JP4173692B2 - Solar cell element and manufacturing method thereof - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a solar cell element. More specifically, the present invention relates to a solar cell element in which a plurality of power generation regions having an insulating translucent substrate, a surface electrode, a photoelectric conversion layer in which a semiconductor film is laminated, and a back electrode are connected in series.
[0002]
Moreover, this invention relates to the manufacturing method of said solar cell element. More specifically, the present invention relates to a method for manufacturing a solar cell element in which a plurality of power generation regions having an insulating translucent substrate, a surface electrode, a photoelectric conversion layer in which a semiconductor film is laminated, and a back electrode are connected in series.
[0003]
[Prior art]
In recent years, the technological development of photovoltaic power generation systems that directly generate electric energy from solar rays using solar cells has progressed rapidly, and a technical prospect is being established as a power generation method that can withstand practical use. As a result, the future of solar power generation systems is expected as a full-fledged clean energy technology that protects the global environment of the 21st century from environmental pollution caused by the burning of fossil energy.
[0004]
Here, the types of solar cell elements used for solar cells are roughly divided into the following four types.
(I) Group IV semiconductor
(Ii) Compound semiconductor (Group III-V, Group II-VI, Group I-III-VI)
(Iii) Organic semiconductor
(Iv) TiO used for wet solar power generation ₂ Compounds such as
Among these materials, Group IV semiconductors are most practically used at present because they can be manufactured at a lower cost than other materials. Group IV semiconductors are broadly divided into (i) crystalline semiconductors and (ii) amorphous semiconductors (also called amorphous semiconductors).
[0005]
Examples of the material of the crystalline semiconductor used as the solar cell element include single crystal silicon, single crystal germanium, polycrystalline silicon, and microcrystalline silicon.
[0006]
Moreover, as an amorphous semiconductor used as a solar cell element, amorphous silicon etc. are mentioned, for example.
[0007]
Here, the solar cell element manufactured using such a semiconductor material is roughly divided into the following three types.
(I) pn junction type
(Ii) Pin junction type
(Iii) Heterojunction type
Among these, in general, a pn junction type is often used in a solar cell element using a crystalline semiconductor having a large carrier diffusion distance. Moreover, in a solar cell element using an amorphous semiconductor with a small carrier diffusion distance and a localized level, it is advantageous to move carriers by drift by an internal electric field in the i layer (intrinsic layer). The pin junction type is often used.
[0008]
In general, a pin junction solar cell element is made of SnO on an insulating translucent substrate such as glass. ₂ A transparent conductive film such as ITO, ZnO or the like is formed, and an amorphous semiconductor p-layer, i-layer, and n-layer are stacked in this order to form a photoelectric conversion layer, and a metal thin film or the like is formed thereon. In many cases, it has a structure in which a back electrode is laminated. Conversely, an n-layer, an i-layer, and a p-layer of an amorphous semiconductor are laminated in this order on a back electrode made of a metal thin film or the like to form a photoelectric conversion layer, and a transparent conductive film is laminated thereon. There is also a pin junction type solar cell element having the following structure.
[0009]
Among these, the method of laminating in order of the p-i-n layer is that the translucent insulating substrate can also serve as a solar cell surface cover glass, and SnO ₂ Plasma-resistant transparent conductive films such as these have been developed, and are now widely used for reasons such as the possibility of laminating a photoelectric conversion layer made of an amorphous semiconductor by plasma CVD. Has become the mainstream.
[0010]
Here, the energy conversion efficiency of the solar cell manufactured using the solar cell element as described above is expressed as a ratio of the solar radiation energy to be input and the electric output energy output from the terminal of the solar cell in%. It is a thing.
[0011]
That is, the conversion efficiency η is
η = (electric output of solar cell) / (solar energy entering the solar cell) × 100%.
[0012]
In order to unify the conversion efficiency measurement standard, the International Electrotechnical Standardization Committee has an air mass passage condition of solar radiation of AM (air mass) of 1.5 and 100 mW / cm. ² The ratio of the input optical power to the maximum electrical output when the load condition is changed, expressed as a percentage, is defined as the nominal efficiency.
[0013]
And the nominal efficiency η of the solar cell _n Is the maximum output point voltage V obtained from the solar cell output measurement method based on the above conditions. _max Maximum output point current I _max , Open circuit voltage V _oc And short circuit photocurrent density I _sc Can be derived from.
[0014]
That is, the input light power of sunlight is P _in The effective light receiving area of the solar cell is represented by S (cm ² )
η _n = (V _max ・ I _max ) / (P _in ・ S) × 100%
= (V _oc ・ I _sc ・ FF) / 100 (mW · cm ^-2 ) X 100%
= V _oc (V) ・ I _sc (MA · cm ^-2 ) FF (%)
It can be expressed as
However, in the above formula, F.I. F. = (V _max ・ I _max ) / (V _oc ・ I _sc ).
[0015]
Here, F.R. F. Is called a fill factor and is treated as an important index indicating the performance of a solar cell.
[0016]
Also, as you can see from the above formula, the input power is 100 mW / cm. ^-2 In measurements normalized to V _oc And I _sc And FF can be obtained, the nominal efficiency of the solar cell can be obtained by obtaining their product.
[0017]
In general, the nominal efficiency of solar cells obtained as described above is about 10 to 20%. That is, about 80 to 90% of solar energy is not converted into electric energy and disappears somewhere. The reason is considered as follows.
[0018]
(I) Sunlight is reflected from the cell surface.
For example, the surface of the silicon plate of a silicon solar cell looks like a dark mirror because light reflects off the cell surface. In general, in order to reduce these reflections, a film for preventing reflection is applied to the cell surface.
[0019]
(Ii) It cannot absorb all wavelengths of sunlight.
Most of the sun rays have a wavelength of 0.2 to 3 μm (ultraviolet rays, visible rays, infrared rays), but the sun rays cannot absorb all these wavelength ranges. Which wavelength is more efficiently converted into electrical energy is affected by the material and manufacturing method of the solar cell.
[0020]
(Iii) The generation rate of free electrons and free holes is not 100%.
Free electrons and free holes may not be generated even when exposed to light, and since they have a lifetime even if they are generated, they may disappear immediately before being taken out as electric energy.
[0021]
(Iv) The yield of free electrons and free holes is not 100%.
Free electrons and free holes generated and separated at the pn junction surface and the like disappear to some extent while moving in the electrode direction.
[0022]
(V) There is resistance inside the solar cell.
Since the silicon material, the electrode part, etc. have electrical resistance, it is impossible to take out all the generated electricity to the outside. F. Decreases.
[0023]
That is, it can be said that the nominal efficiency of the current solar cell can be further improved by eliminating or reducing these causes.
[0024]
In addition to these efforts, efforts are also being made to improve the nominal efficiency of solar cells by increasing the integration to provide more photoelectric conversion layers on the substrate of the solar cells.
[0025]
For example, in a solar cell element called a multi-junction type, by laminating a large number of photoelectric conversion layers in the light traveling direction, light from the short wavelength side is sequentially absorbed in each photoelectric conversion layer, and each forbidden band width The structure is designed to generate a voltage commensurate with Eg.
[0026]
In addition, in order to increase the light absorption efficiency in the photoelectric conversion layer, a material having high reflectance such as Ag or Al is used as the back electrode of the solar cell element, and a transparent electrode is sandwiched between the photoelectric conversion layer and the back electrode. Thus, a method of scattering the light and increasing the optical path length of the incident light in the photoelectric conversion layer to improve the conversion efficiency of the solar cell is often used together. At this time, as the transparent electrode, for example, SnO ₂ In many cases, a material containing ZnO, ITO, or the like is used.
[0027]
Moreover, in order to further increase the voltage generated in one power generation region of the solar cell element, development of a solar cell element having a power generation region in which a photoelectric conversion layer is laminated on two to three layers has been actively performed in recent years. Furthermore, in order to effectively use the energy of different wavelengths of solar rays, the development of solar cell elements having a multi-band gap type power generation region in which the upper photoelectric conversion layer and the lower photoelectric conversion layer have different band gaps has also been promoted. ing.
[0028]
Here, in general, when an electronic device is driven by a solar cell or a solar cell is used for electric power, the voltage generated at one power generation region is generally 1 V or less, and thus a plurality of power generation regions are connected in series. It is necessary to use a solar cell element having a large area having a connected structure.
[0029]
For example, a general solar cell element is formed on an insulating substrate by using a patterning process. In this case, a transparent electrode, a photoelectric conversion layer is formed on a light-transmitting insulating substrate such as one glass substrate. A plurality of power generation regions having a back electrode are formed, and a structure in which these adjacent power generation regions are connected in series is often used.
[0030]
Further, in the patterning process of the above solar cell element, conventionally, patterning by etching using a resin mask or the like has been performed. However, such a method requires many processes for forming the laminated structure, and there are restrictions on the size of the substrate that can be handled, and the effective area of the power generation region in the substrate of the solar cell tends to be small, so that the wet process Therefore, pinholes are easily generated in the photoelectric conversion layer, and patterning is difficult on a curved substrate.
[0031]
On the other hand, patterning using heating by laser irradiation has recently been developed and is actively used. This patterning method using a laser can reduce the formation process of the laminated structure, can manufacture a solar cell element on a large-area substrate, and can form a solar cell on a substrate having an arbitrary structure such as a curved surface. The battery element can be manufactured, and the effective area of the power generation area in the substrate of the solar cell can be increased, which is advantageous for continuous integrated production and automated production.
[0032]
In particular, in patterning by etching using a conventional resin mask or the like, a distance of about 3 mm from the adjacent power generation region is required. By adopting patterning using heating by laser irradiation, the distance is reduced to 0. It can be shortened to 5 mm or less. Therefore, by employing patterning using heating by laser irradiation, the output per unit area of the solar cell element can be generally improved by 30% or more through the increase of the effective area of the power generation region in the substrate of the solar cell. it can.
[0033]
[Problems to be solved by the invention]
In a solar cell element having a power generation region in which such photoelectric conversion layers are stacked (also referred to as a stacked solar cell element in this specification), for example, the power generation region is an upper photoelectric conversion layer (in this specification, an upper part). In the case of a power generation region having a two-layer structure consisting of a cell and a lower photoelectric conversion layer (also referred to as a lower cell in this specification), the contact property between the upper cell n layer and the lower cell p layer, etc. Thus, the power generation efficiency of the stacked solar cell element is generally affected.
[0034]
Here, a solar cell element provided with a power generation region having an i layer of a semiconductor thin film mainly made of amorphous silicon in the upper cell and an i layer of a semiconductor thin film mainly made of microcrystalline silicon in the lower cell. When solar power generation is used, in the manufacturing process of the solar cell element, by making the n layer of the upper cell microcrystallized, the p layer of the lower cell laminated on the surface is easily microcrystallized, Further, the i layer of the lower cell laminated on the surface is also easily crystallized. As a result, an i-layer of the lower cell whose main material is good quality microcrystalline silicon is obtained, and the power generation efficiency of the solar cell element is improved. Therefore, in order to improve the power generation efficiency of the solar cell element, it is effective to increase the crystallization rate of the microcrystal of the n layer of the upper cell.
[0035]
Further, in order to microcrystallize the n layer of the upper cell, the contact with the p layer of the lower cell is improved, and the F.V. F. As a result, there is also an advantage that the power generation efficiency of the solar cell element is stabilized.
[0036]
Here, in order for such a stacked solar cell to generate a sufficient voltage, a stacked structure in which a power generation region in which a plurality of photoelectric conversion layers are stacked is connected in series (also referred to as a serial stacked structure in this specification). It is necessary to have However, in a stacked solar cell element having a structure having a semiconductor thin film mainly composed of microcrystalline silicon in the n layer of the upper cell, patterning using heating by laser irradiation (in this specification, laser patterning is used). When a series stacked structure is formed by a conventionally known method such as the above-mentioned method, there is a problem that a short circuit occurs in the upper cell and the output of the stacked solar cell element may be reduced.
[0037]
Even when a series stacked structure is formed in a solar cell element having a structure having microcrystalline silicon in the n-layer of the upper cell, the back electrode and the front electrode are connected by a contact line filled with a conductive material, and adjacent power generation regions Need to be connected in series. However, in a solar cell element having such a structure, when such a contact line is formed using a conventionally known method such as laser patterning, the contact line and the n layer of the upper cell are in direct contact with each other. There are many.
[0038]
For example, when a series stacked solar cell having a power generation region consisting of a two-layer structure of an upper cell and a lower cell in a general series stacked structure, similar to the case where the n layer of the upper cell is not microcrystalline silicon, The structure shown in FIG.
[0039]
However, in the case of such a serially stacked structure, when the n layer (that is, the first n layer) 3b of the upper cell is microcrystalline silicon, depending on the film formation conditions, the n layer (that is, the first layer) of the upper cell. n layer) 3b and the contact line 8 may cause a leakage current. That is, when the adjacent power generation regions are connected by the contact line 8 that electrically connects the back electrode 5 and the front electrode 2, the n-layer (that is, the first n layer) 3 b of the upper cell and the groove of the contact line 8 And will be in direct contact. Therefore, the upper cell 3 is short-circuited, and there arises a problem that the output of this series stacked solar cell element is lower than the original output.
[0040]
In FIG. 4, reference numeral 1 denotes an insulating translucent substrate, 2 denotes a surface electrode, 3a denotes a first p layer and i layer, 4 denotes a lower cell, 6 denotes a surface electrode separation line, and 9 denotes a surface electrode separation line. Each of the back electrode separation lines is shown.
[0041]
In order to overcome such problems, a great deal of research and development efforts are currently being made in many directions. For example, Japanese Patent Laying-Open No. 9-129903 discloses a serial laminated structure as shown in FIG. However, in the case of the serial laminated structure as shown in FIG. 5, when the surface electrode 2 and the upper cell 3 are simultaneously subjected to laser patterning, if the surface electrode 2 is not sufficiently processed, the surface electrodes 2 are separated between the power generation regions. Even when the surface electrode 2 sublimated on the side surface of the upper cell 3 is reattached and cleaning such as ultrasonic cleaning is performed thereafter, the n layer of the upper cell (that is, the first n layer) There is a case where a short circuit occurs between 3b and the surface electrode 2 to cause a decrease in output of the solar cell element, which causes a decrease in yield in the manufacturing process of the solar cell element.
[0042]
Further, in the solar cell element having the serially stacked structure as shown in FIG. 5, when the lower cell 4 is formed by a CVD method using a material containing microcrystalline silicon as the material of the lower cell 4, The lower cell 4 requires a thick film thickness of 2 μm or more. In addition, in this case, since there is a portion where the lower cell 4 and the insulating translucent substrate 1 are in direct contact, depending on the film formation conditions of the lower cell 4 in the lower cell 4 formation process, the lower cell 4 Peeling occurs frequently. For this reason, the reliability of the solar cell element is lowered, and the yield in the manufacturing process of the solar cell element is lowered. Therefore, there is a problem that the efficiency of the solar cell element is restricted.
[0043]
Also, in the normal manufacturing process of solar cell elements, the separation resistance between cells is measured after laser scribing of the surface electrode 2, and if the separation is not sufficient, it can be excluded so that it does not flow to the subsequent process, or the processing failure In general, by repairing the location, the solar cell element material is effectively used or the average output of the solar cell element is improved. However, in the manufacturing process of the solar cell element having the structure shown in FIG. 5, since the above-mentioned separation cannot be confirmed and the defective processing place cannot be repaired, a part of the material of the solar cell element is wasted, and the average output of the solar cell element There is a problem that decreases.
[0044]
Then, in the manufacturing process of the solar cell element having the serial laminated structure as shown in FIG. 5, in order to remove the residue of the surface electrode 2 after the laser scribing of the surface electrode 2 after the formation of the first n layer 3b. Ultrasonic cleaning is essential in pure water. At this time, in the case where there is no conductive layer on the back side of the first n layer 3b, the contact property between the first n layer 3b and the p layer of the lower cell 4 is improved by washing in pure water. The F. of the solar cell element becomes worse. F. There was also a problem that this could lead to a decrease in the quality.
[0045]
In FIG. 5, reference numeral 3a denotes the first p layer and i layer, 5 denotes the back electrode, 6 denotes the front electrode separation line, 8 denotes the contact line, and 9 denotes the back electrode separation line. To do.
[0046]
Japanese Patent Laid-Open No. 9-129906 discloses a serial stacked structure as shown in FIG.
[0047]
Here, also in the solar cell element having the serial laminated structure as shown in FIG. 6, when the lower cell 4 is formed by the CVD method, the lower cell needs to have a thick film thickness of 2 μm or more. Since there is a portion where the cell 4 and the insulating translucent substrate 1 are in direct contact, the lower cell 4 may be peeled off frequently in the formation process of the lower cell 4 depending on the film formation conditions of the lower cell 4. There is a problem that the yield is lowered in the manufacturing process of the solar cell element and the efficiency of the element is restricted.
[0048]
In FIG. 6, reference numeral 1 denotes an insulating translucent substrate, 2 denotes a surface electrode, 3 denotes an upper cell, 3a denotes a first p-layer and i-layer, 3b denotes a first n-layer, 5 Denotes a back electrode, 6 denotes a surface electrode separation line, 8 denotes a contact line, 9 denotes a back electrode separation line, and 38 denotes a surface electrode / first n-layer isolation member.
[0049]
As described above, a solar cell element having a serial stacked structure in which the first n layer 3b made of a semiconductor thin film mainly composed of microcrystalline silicon is formed between the i layer of the upper cell and the p layer of the lower cell. In order to prevent short circuit between the back electrode 5 and the first n layer 3b made of a semiconductor thin film made mainly of microcrystalline silicon, it is necessary to adopt a specific structure. However, in the conventionally known structures, the problems that the reliability of the solar cell element is reduced, the yield of the manufacturing process of the solar cell element is reduced, and the characteristics of the solar cell element are not overcome.
[0050]
Therefore, based on the above-described present situation, an object of the present invention is to provide a solar cell element having a series laminated structure that is excellent in power generation efficiency per unit area and can be manufactured with high reliability and yield.
[0051]
Another object of the present invention is to provide a method for manufacturing a solar cell element capable of manufacturing a solar cell element having a series laminated structure excellent in power generation efficiency per unit area with high reliability and yield. .
[0052]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, the present inventors may form a structure in which the first n layer made of a semiconductor thin film mainly composed of microcrystalline silicon and the contact line are not in direct contact with each other. In order to find a structure of a solar cell element capable of forming a series laminated structure of such a structure and capable of being manufactured with high reliability and yield, We conducted experiments with a combination of manufacturing processes and conducted extensive studies.
[0053]
After the study, the present inventors have made a single or a plurality of non-conductors and / or semiconductors between the first n layer made of a semiconductor thin film made mainly of microcrystalline silicon and the contact line. The series stacked solar cell element having a structure in which the first n layer made of a semiconductor thin film mainly composed of microcrystalline silicon and the contact line are not in direct contact with each other has a power generation efficiency per unit area. The present invention has been completed by finding that it is excellent and can be manufactured with high reliability and yield.
[0054]
That is, in the solar cell element of the present invention, at least an insulating translucent substrate, a surface electrode, a power generation region having a photoelectric conversion layer laminated with a semiconductor film and a back electrode, and a surface electrode and a back electrode between adjacent power generation regions are electrically connected. A plurality of power generation regions connected in series, wherein the power generation region includes at least a first p-layer, an i-layer, and an n-layer photoelectric conversion layer. , A second p layer, an i layer, and a photoelectric conversion layer composed of an n layer are sequentially stacked, and the first n layer is a semiconductor film containing microcrystalline silicon, A single or a plurality of members made of a non-conductor and / or a semiconductor is provided between the n layer and the contact line, and the first n layer and the contact line have a structure that is not in direct contact. Solar cell element A.
[0055]
Here, in the solar cell element of the present invention, a single member or a plurality of members made of a nonconductor and / or a semiconductor provided between the first n layer and the contact line are formed from the first n layer. Also, it is desirable that the member is made of a material having the same composition as a part of the photoelectric conversion layer provided on the back surface side.
[0056]
Furthermore, in the solar cell element of the present invention, the single member or the plurality of members made of a nonconductor and / or a semiconductor provided between the first n layer and the contact line are more than the first n layer. It is recommended that the semiconductor film be included in the photoelectric conversion layer provided on the back surface side, and be a member made of a semiconductor having the same composition as that of the semiconductor film provided closest to the light incident side in the photoelectric conversion layer. The
[0057]
And in the solar cell element of this invention, the single or several member which consists of a nonconductor and / or the semiconductor with which the 1st n layer and the contact line were equipped is more than this 1st n layer. A portion made of a material having the same composition as a part of the photoelectric conversion layer provided on the light incident side, and a material having the same composition as a part of the photoelectric conversion layer provided on the back side of the first n layer It may be a member combined with a portion consisting of
[0058]
In the solar cell element of the present invention, the single member or the plurality of members made of a nonconductor and / or a semiconductor provided between the first n layer and the contact line are more than the first n layer. A portion made of a single or a plurality of semiconductors having the same composition as that of a single or a plurality of semiconductor films included in a photoelectric conversion layer provided on the light incident side, and provided on the back side of the first n layer It is a semiconductor film included in the photoelectric conversion layer, and may be a composite member with a portion made of a semiconductor having the same composition as the semiconductor film provided closest to the light incident side in the photoelectric conversion layer.
[0059]
Here, in the solar cell element of the present invention, the surface electrode is preferably made of a transparent conductive film using a material containing zinc oxide, tin oxide or ITO.
[0060]
In the solar cell element of the present invention, among the photoelectric conversion layers, the first p layer and the i layer are semiconductor films mainly composed of a-Si: H, and the first n layer is μc−. It is recommended that the semiconductor film is made of Si: H as a main material, and the second p layer, i layer, and n layer are semiconductor films made of μc-Si: H as a main material.
[0061]
In the solar cell element of the present invention, the back electrode has a structure in which a transparent conductive film using a material containing zinc oxide, tin oxide or ITO and a metal film using a material containing Ag or Al are laminated. Preferably there is.
[0062]
In the solar cell element of the present invention, the contact line is preferably a member using a material having the same composition as a part of the back electrode.
[0063]
Here, this invention is a manufacturing method of said solar cell element, Comprising: As A process, the process of forming a 1st p layer, i layer, and n layer in order, As B process, this 1st n Forming a first n-layer separation line that penetrates the layer and the member sandwiched between the first n-layer and the surface electrode and reaches the surface on the back surface side of the surface electrode; A second p-layer, an i-layer, and an n-layer in contact with the outer surface of the first n-layer and the first n-layer separation line A step of forming layers sequentially, and a step of forming a contact line through the member sandwiched between the back electrode and the front electrode and reaching the back surface side surface of the front electrode as the D step, The cross section of the first n-layer separation line by a plane or curved surface parallel to the conductive insulating substrate is the coplanar by the plane or curved surface. It includes a method of making a solar cell element characterized in that it comprises the open groove of the cross section of the tact line.
[0064]
Moreover, this invention is a manufacturing method of said solar cell element, Comprising: As A process, the process of forming a 1st p layer, i layer, and n layer in order, As this B process, this 1st n layer Forming a first n-layer separation line that penetrates the first p-layer and / or part of the first p-layer and / or the i-layer, and as a C-step, the back side of the first n-layer and the n-layer In the layer separation line, a step of forming a second p layer, an i layer, and an n layer in order so as to be in contact with the outline of the first n layer and the first n layer separation line; Forming a contact line groove extending through the member sandwiched between the back electrode and the front electrode and reaching the surface on the back surface side of the front electrode, and comprising a plane or curved surface parallel to the translucent insulating substrate. The cross section of one n-layer separation line includes the cross section of the groove of the contact line by the plane or curved surface It includes a method of making a solar cell element characterized Rukoto.
[0065]
And in the manufacturing method of the solar cell element of this invention, it is preferable to form the open groove | channel of a 1st n layer separation line and a contact line by irradiating a laser.
[0066]
In the method for manufacturing a solar cell element of the present invention, it is desirable that the maximum diameter of the laser beam cross section used in the D process is smaller than the maximum diameter of the laser beam cross section used in the B process.
[0067]
Moreover, in the manufacturing method of the solar cell element of this invention, it is recommended that a photoelectric converting layer is formed using a plasma CVD method.
[0068]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in more detail with reference to embodiments.
[0069]
<Structure of solar cell element>
The solar cell element of the present invention electrically includes at least an insulating translucent substrate, a surface electrode, a power generation region having a photoelectric conversion layer laminated with a semiconductor film and a back electrode, and a front electrode and a back electrode between adjacent power generation regions. A solar cell element having a plurality of power generation regions connected in series, wherein the power generation region includes at least a first p-layer, an i-layer, an n-layer photoelectric conversion layer, A photoelectric conversion layer composed of two p-layers, i-layers, and n-layers is sequentially stacked; and the first n-layer is a semiconductor film containing microcrystalline silicon, and the first n-layer And a contact line comprising a single member or a plurality of members made of a nonconductor and / or a semiconductor, and the first n layer and the contact line have a structure that does not directly contact It is a battery element.
[0070]
<Insulating translucent substrate>
The insulating translucent substrate used for the solar cell element of the present invention is not particularly limited as long as it has insulating properties and translucency, and a substrate generally used for a solar cell element can be used. Specific examples of the insulating translucent substrate used in the present invention include a substrate using glass, quartz, transparent plastic, or the like as a material.
[0071]
However, the insulating translucent substrate used in the present invention does not need to have insulating properties at all sites, and can be used as long as at least the surface electrode formation surface is insulated. That is, even a conductive substrate can be used as an insulating translucent substrate used in the present invention by covering the surface electrode formation surface with an insulator.
[0072]
<Surface electrode>
The surface electrode used for the solar cell element of the present invention is formed on an insulating translucent substrate. Here, the surface electrode used for this invention will not be specifically limited if it has electroconductivity and translucency, The surface electrode generally used for a solar cell element can be used. The surface electrode used in the present invention is preferably a film electrode made of a material having transparency and conductivity (also referred to as a transparent conductive film in this specification).
[0073]
However, the surface electrode used in the present invention does not have to be transparent at all sites, and at least some of the sites are transparent and can transmit the amount of light required for photovoltaic power generation. If it has the transparency which can be used, it can be used. That is, even an electrode using a non-transparent material such as a metal can be used as a surface electrode used in the present invention because it has translucency if the structure is a lattice, for example.
[0074]
Specific examples of the surface electrode used in the present invention include a transparent conductive film using tin oxide, zinc oxide, ITO, or the like as a material. Here, SnO includes SnO ₂ As well as Sn _m O _n It is assumed that tin oxides of various compositions represented by (where m and n are positive integers) are included. Zinc oxide includes not only ZnO but also ZnO. _{m '} O _{n '} (Here, m ′ and n ′ are positive integers) and zinc oxides having various compositions are included. ITO is an abbreviation for Indium Tin Oxide, which means indium tin oxide.
[0075]
Where ITO and SnO ₂ In both cases, there is little difference in terms of translucency, but in general ITO is superior in terms of low specific resistance, and SnO in terms of chemical stability. ₂ Is considered excellent. Further, ZnO has an advantage that the material cost is lower than that of ITO. In addition, SnO ₂ In some cases, the reduction of the surface by plasma may be a problem when forming an a-Si film, whereas ZnO has high plasma resistance. In addition, ZnO has an advantage that it has a high transmittance for long-wavelength light.
[0076]
Moreover, when the surface electrode used for this invention consists of a transparent conductive film which consists of a material containing ZnO, you may dope impurities, such as Al and Ga, for the low resistance of a transparent conductive film. Among these impurities, it is preferable to dope Ga, which is excellent in the property of lowering resistance.
[0077]
Furthermore, when the surface electrode used for this invention is a transparent conductive film, it is preferable that the surface has an unevenness | corrugation. By forming minute irregularities on the surface of the surface transparent conductive film, light can be scattered in the power generation region provided in the solar cell element, and the optical path length of the light is extended. Therefore, the power generation efficiency of the solar cell element can be improved as compared with the case where the surface of the surface transparent conductive film is not uneven.
[0078]
<Photoelectric conversion layer>
If the photoelectric conversion layer used for the solar cell element of the present invention has a structure in which semiconductor films are stacked, the first n layer is a semiconductor film containing microcrystalline silicon, and has photoelectric conversion properties, It does not specifically limit, The photoelectric converting layer generally used for a solar cell element can be used.
[0079]
Here, as a material of the photoelectric conversion layer used in the present invention, a material generally used for a photoelectric conversion layer of a solar cell element can be used as long as it is a semiconductor. Specific examples include Si, Ge, SiGe, Semiconductors such as SiC, SiN, GaAs, and SiSn can be used. Of these, silicon-based semiconductors such as Si, SiGe, and SiC are preferably used.
[0080]
Further, the semiconductor that is a material of the photoelectric conversion layer used in the present invention may be a crystalline semiconductor such as a microcrystalline or polycrystalline type, or may be an amorphous semiconductor such as an amorphous type. Here, as the amorphous semiconductor and the polycrystalline semiconductor, it is preferable to use a hydrogenated semiconductor having a chemical structure in which a dangling bond causing a localized level is terminated with hydrogen. However, the semiconductor which is the material of the first n layer used in the present invention needs to be a semiconductor containing microcrystalline silicon.
[0081]
Further, the semiconductor film of the first photoelectric conversion layer and the second photoelectric conversion layer used in the present invention needs to have a p-type, i-type, and n-type three-layer structure. Here, the p-type and n-type semiconductors can be formed by doping predetermined impurities. Further, the three-layer structure needs to be a pin type structure in which a p layer, an i layer, and an n layer are stacked in order from the light incident surface side.
[0082]
Furthermore, the power generation region provided in the solar cell element of the present invention has two or more photoelectric conversion layers stacked. Here, the power generation region provided in the solar cell element of the present invention may have a so-called tandem structure in which two photoelectric conversion layers are stacked, or may have a structure in which three or more photoelectric conversion layers are stacked. Good. Further, the two or more stacked photoelectric conversion layers may be photoelectric conversion layers having the same structure and / or material, but may be photoelectric conversion layers having different structures and / or materials.
[0083]
Here, the power generation region provided in the solar cell element of the present invention preferably has a structure in which two photoelectric conversion layers are stacked. Further, in the solar cell element having such a structure, the photoelectric conversion layer including the first n layer, the upper photoelectric conversion layer (in this specification, a photoelectric conversion layer provided on the light incident surface side) (Also called an upper cell) is a photoelectric layer consisting of a hydrogenated amorphous silicon semiconductor (a-Si: H) p-layer and an i-layer, and a hydrogenated microcrystalline silicon-based semiconductor n-type three-layer structure. A conversion layer is preferred.
[0084]
Moreover, in the solar cell element having such a structure, the photoelectric conversion layer is in contact with the first n layer and is provided on the opposite side of the light incident surface from the first n layer. A certain lower photoelectric conversion layer (also referred to as a lower cell in this specification) is a photoelectric conversion layer having a p-i-n type three-layer structure of a hydrogenated polycrystalline silicon-based semiconductor (μc-Si: H). Preferably there is.
[0085]
<Back electrode>
The back electrode used in the present invention is formed on the opposite side (also referred to as the back side in this specification) of the two or more photoelectric conversion layers stacked. In addition, the back electrode used in the present invention is not particularly limited as long as it has light scattering or light reflectivity in addition to conductivity, and the back electrode generally used for solar cell elements can be preferably used. it can.
[0086]
Furthermore, the back electrode used in the present invention is preferably a laminate of a back transparent electrode and a back metal electrode. In addition, the back electrode used in the present invention may be composed only of the back metal electrode, and the back transparent electrode may be omitted, but in order to promote light scattering and obtain high power generation efficiency, It is desirable to have a transparent electrode.
[0087]
And as a specific example of the back surface metal electrode used for this invention, the metal film which used Ag, Al, Cr, etc. which were excellent in light reflectivity as a material is mentioned.
[0088]
Further, specific examples of the back transparent electrode used in the present invention include a transparent conductive film using tin oxide, zinc oxide, ITO, or the like as a material. Here, SnO includes SnO ₂ As well as Sn _m O _n It is assumed that tin oxides of various compositions represented by (where m and n are positive integers) are included. Zinc oxide includes not only ZnO but also ZnO. _{m '} O _{n '} (Here, m ′ and n ′ are positive integers) and zinc oxides having various compositions are included. ITO is an abbreviation for Indium Tin Oxide, which means indium tin oxide.
[0089]
Where ITO and SnO ₂ In both cases, there is little difference in terms of translucency, but in general ITO is superior in terms of low specific resistance, and SnO in terms of chemical stability. ₂ Is considered excellent. Further, ZnO has an advantage that the material cost is lower than that of ITO. In addition, SnO ₂ In some cases, reduction of the surface by plasma or the like may cause a problem, whereas ZnO has high plasma resistance. In addition, ZnO has an advantage that it has a high transmittance for long-wavelength light.
[0090]
Moreover, when the back surface transparent electrode used for this invention consists of a transparent conductive film which consists of a material containing ZnO, you may dope impurities, such as Al and Ga, for the low resistance of a transparent conductive film. Among these impurities, it is preferable to dope Ga, which is excellent in the property of lowering resistance.
[0091]
Furthermore, it is preferable that the back surface transparent electrode used for this invention has the unevenness | corrugation formed in the surface. By forming minute irregularities on the surface of the back transparent electrode, light can be scattered in the power generation region provided in the solar cell element, and the optical path length of the light is extended. Therefore, the power generation efficiency of the solar cell element can be improved as compared with the case where there is no unevenness on the surface of the back transparent electrode.
[0092]
And the unevenness | corrugation of the surface of the back surface transparent electrode used for this invention can be simply and correctly formed by using the etching by a general etching solution.
[0093]
<Series laminated structure>
The solar cell element of the present invention electrically includes at least an insulating translucent substrate, a surface electrode, a power generation region having a photoelectric conversion layer laminated with a semiconductor film and a back electrode, and a front electrode and a back electrode between adjacent power generation regions. A solar cell element having a plurality of power generation regions connected in series, wherein the power generation region includes at least a first p-layer, an i-layer, an n-layer photoelectric conversion layer, A photoelectric conversion layer composed of two p-layers, i-layers, and n-layers is sequentially stacked; and the first n-layer is a semiconductor film containing microcrystalline silicon, and the first n-layer And a contact line comprising a single member or a plurality of members made of a nonconductor and / or a semiconductor, and the first n layer and the contact line have a structure that does not directly contact It is a battery element.
[0094]
Here, in the solar cell element of the present invention, in order to realize such a structure in which a plurality of power generation regions are connected in series (also referred to as a series stacked structure in this specification), between adjacent power generation regions Thus, the front electrodes, the photoelectric conversion layers, and the back electrodes need to be completely separated from each other. Moreover, in order for the solar cell element of the present invention to realize an integrated structure, the front electrode and the back electrode need to be connected in order between adjacent power generation regions.
[0095]
Therefore, the solar cell element of the present invention includes an open groove for separating the surface electrode (also referred to as a surface electrode separation line in this specification) and an open groove for separating the photoelectric conversion layer (in this specification). , Also referred to as a photoelectric conversion layer separation line), an open groove for separating the first n layer (also referred to herein as a first n layer separation line), and an opening for separating the back electrode. It is necessary to have a groove (also referred to as a back electrode separation line in this specification).
[0096]
Here, the inside of the open groove is not limited to the case of a gap, and a non-conductor, a semiconductor, a conductor, or the like may exist or be filled in a film shape. In the book, it will be called an open groove.
[0097]
In addition, in the solar cell element of the present invention, in order to realize the serial stacked structure, it is necessary to have a member (also referred to as a contact line in this specification) for electrically connecting the front surface electrode and the back surface electrode. is there.
[0098]
Furthermore, in the solar cell element of the present invention, in order to realize a serial stacked structure and to prevent a decrease in the output of the solar cell element due to a short circuit between the first n layer and the contact line, A first n layer and a contact line, each having a single or a plurality of members made of a nonconductor and / or a semiconductor (also referred to as an intermediate transparent conductive film / contact line isolation member in this specification) between the contact line and the contact line. It is also necessary to have a structure that does not come into direct contact with.
[0099]
Here, the first n-layer separation line preferably has a structure that completely separates the first n-layer, the first p-layer, and the i-layer together. However, the first n-layer separation line may have a structure in which the first n-layer is completely separated, but the first p-layer and i-layer are not completely separated. However, in this case, as will be described later, the contact line provided inside the first n-layer separation line needs to completely separate the first p-layer and i-layer.
[0100]
Moreover, it is preferable to provide said contact line which electrically connects the surface electrode and back surface electrode of adjacent electric power generation area | regions inside a 1st n layer separation line. The contact line is preferably made of a material having the same composition as a part of the back electrode. Furthermore, the contact line preferably has a shape that completely separates the photoelectric conversion layer as described above.
[0101]
Here, the member for isolating the first n layer from the contact line (also referred to herein as the first n layer / contact line isolating member) is the first n layer and the contact line. In order to prevent a decrease in the output of the solar cell element due to a short circuit, the first n layer is provided inside the first n layer separation line and the first n layer and the contact line are not in direct contact with each other. It is preferable to provide a structure inserted between the layer and the contact line.
[0102]
From the viewpoint of simplifying the manufacturing process, the material of the first n-layer separation line 7 is, as shown in FIG. 1, a lower cell 4 provided on the back side of the first n-layer 3b. It is preferable that the material has the same composition as a part of
[0103]
Furthermore, the material of the first n layer / contact line isolation member is a semiconductor film included in the photoelectric conversion layer provided on the back side of the first n layer from the viewpoint of simplifying the manufacturing process. In addition, it is particularly preferable that the material has the same composition as that of the semiconductor film provided closest to the light incident side in the photoelectric conversion layer.
[0104]
Further, the first n layer / contact line isolation member 18 does not need to be made of a single material, and is provided on the light incident side with respect to the first n layer 3b, for example, as shown in FIG. In addition, the first n layer / contact line isolation member 18 which is a part made of the material having the same composition as the first p layer and a part of the i layer 3a, and provided on the back side of the first n layer It may be a member combined with a first n-layer separation line 7 made of a material having the same composition as a part of the lower cell 4.
[0105]
The first n layer / contact line isolation member is the same as the single or plural semiconductor films included in the p layer and i layer of the upper cell provided on the light incident side with respect to the first n layer. And a semiconductor film included in a photoelectric conversion layer provided on the back side of the first n layer, and the most light incident in the photoelectric conversion layer It may be a member that is combined with a portion made of a semiconductor having the same composition as the semiconductor film provided on the side.
[0106]
That is, as the material of the first n layer / contact line isolation member, for example, a semiconductor such as Si, Ge, SiGe, SiC, SiN, GaAs, or SiSn can be used. Of these, silicon-based semiconductors such as Si, SiGe, and SiC are preferably used.
[0107]
The semiconductor that is the material of the first n-layer / contact line isolation member may be a crystalline semiconductor such as a polycrystalline type or a microcrystal, or an amorphous semiconductor such as an amorphous type. However, it should be a separator that does not cause leakage current in the first n layer and the contact line. Here, as the amorphous semiconductor and the polycrystalline semiconductor, it is preferable to use a hydrogenated semiconductor having a chemical structure in which a dangling bond causing a localized level is terminated with hydrogen.
[0108]
Furthermore, the semiconductor that is the material of the first n layer / contact line isolation member may be any of p-type, i-type, and n-type. Here, the p-type and n-type semiconductors can be formed by doping predetermined impurities.
[0109]
Further, in the solar cell element of the present invention, in the case of having two photoelectric conversion layers (upper cell 3, lower cell 4) in which one power generation region is laminated, the first n-layer separation line 7 is As shown in FIG. 1, it is preferable to provide a single layer.
[0110]
On the other hand, in the solar cell element of the present invention, one power generation region has a second n layer 4b made of a semiconductor film containing microcrystalline silicon in addition to the first n layer 3b, and has three photoelectric conversion layers ( In the case of having the upper cell 3, the lower cell 4, and the third photoelectric conversion layer 23), the first n layer and the second n layer separation line 25 are dependent on the thickness of the photoelectric conversion layer. Considering simplification of the process, it is preferable to provide a single layer as shown in FIG. 7 as in the case of the two photoelectric conversion layers.
[0111]
In FIG. 7, reference numeral 1 denotes an insulating translucent substrate, 2 denotes a front electrode, 3a denotes a first p layer and i layer, 4a denotes a second p layer and i layer, and 5 denotes a back electrode. , 6 is a surface electrode separation line, 8 is a contact line, and 9 is a back electrode separation line.
[0112]
<Method for producing solar cell element>
The manufacturing method of the solar cell element of the present invention is the above-described manufacturing method of the solar cell element, and as the A step, the step of forming the first p layer, the i layer, and the n layer in order, and the B step, A step of forming a first n-layer separation line extending through the first n-layer and the member sandwiched between the first n-layer and the surface electrode to reach the surface on the back surface side of the surface electrode; A second p layer in contact with the outer surface of the first n layer and the first n layer separation line, on the back side of the first n layer and in the first n layer separation line, A step of sequentially forming an i layer and an n layer, and a step of forming a contact line groove extending through the member sandwiched between the back electrode and the front electrode and reaching the back surface of the front electrode as the D step. A cross section of the first n-layer separation line by a plane or curved surface parallel to the translucent insulating substrate is the plane or It is preferred according to the curved surface is a manufacturing method of a solar cell element characterized in that it comprises a cross-section of the open groove of the contact line.
[0113]
Moreover, the manufacturing method of the solar cell element of this invention is a manufacturing method of said solar cell element, Comprising: As a process, the process of forming a 1st p layer, i layer, n layer in order, and B process Forming a first n-layer separation line that penetrates through the first n-layer and partially removes the first p-layer and / or i-layer; A second p-layer, an i-layer, and an n-layer are sequentially formed so as to be in contact with the outer surface of the first n-layer and the first n-layer separation line on the back side of the layer and in the n-layer separation line. The step and the step D include a step of forming a contact line groove extending through the member sandwiched between the back electrode and the front electrode and reaching the surface on the back surface side of the front electrode, parallel to the translucent insulating substrate. The cross section of the first n-layer separation line by a flat or curved surface is the contact by the flat or curved surface. May be a method for manufacturing a solar cell element characterized in that it comprises a cross-section of the in-the open grooves.
[0114]
<Surface electrode formation process>
In the method for manufacturing a solar cell element of the present invention, in the step of forming the surface electrode on the insulating translucent substrate (also referred to herein as the surface electrode forming step), is the surface electrode a metal electrode? The process differs depending on whether it is a transparent conductive film.
[0115]
Here, when the surface electrode used for this invention is a metal electrode, a physical manufacturing method can be used as a surface electrode formation process.
[0116]
The physical production method is not particularly limited, and examples thereof include a vacuum deposition method, an ion plating method, a sputtering method, and a magnetron sputtering method. Of these manufacturing methods, it is preferable to use a sputtering method in terms of quality and the like.
[0117]
Moreover, when the surface electrode used for this invention consists of a transparent conductive film, a chemical manufacturing method or a physical manufacturing method can be used as a surface electrode formation process.
[0118]
Here, the chemical production method is not particularly limited, and examples thereof include a spray method, a CVD method, and a plasma CVD method. In general, the chemical production method is a method of forming an oxide film on a substrate by thermal decomposition or oxidation reaction of chloride or an organometallic compound, and has an advantage that process cost is low.
[0119]
On the other hand, examples of the physical production method include a vacuum deposition method, an ion plating method, a sputtering method, and a magnetron sputtering method. In general, the physical manufacturing method has a lower substrate temperature than the chemical manufacturing method and can form a high-quality film, but has a tendency that the film forming speed is low and the cost of the apparatus is high.
[0120]
<Surface electrode patterning process>
In the method for manufacturing a solar cell element of the present invention, the patterning technique is particularly limited in the step of patterning the surface electrode to form the surface electrode separation line (also referred to as a surface electrode patterning step in this specification). Any technique that can be used for patterning a metal electrode or a transparent conductive film can be suitably used as long as it can be accurately patterned.
[0121]
In the surface electrode patterning step in the present invention, for example, patterning by etching using a resin mask or a metal mask may be performed. However, such a method requires many processes for forming the laminated structure, and there are restrictions on the size of the substrate that can be handled, and the effective area of the power generation region in the substrate of the solar cell tends to be small, so that the wet process Therefore, pinholes are easily generated in the photoelectric conversion layer, and patterning is difficult on a curved substrate.
[0122]
Therefore, in the surface electrode patterning step in the present invention, it is preferable to perform patterning using heating by laser irradiation (also referred to as laser patterning in this specification). By performing such laser patterning, the number of steps required for forming the laminated structure can be reduced, a solar cell element can be manufactured on a large-area substrate, and a substrate with an arbitrary shape such as a curved surface The solar cell element can be manufactured on the top, the effective area of the power generation region in the substrate of the solar cell can be increased, and there is an advantage that it is suitable for continuous integrated production and automated production.
[0123]
Here, in the surface electrode patterning step in the present invention, the laser used for laser patterning is not particularly limited, and a laser generally used in a method for manufacturing a solar cell element can be used.
[0124]
In the surface electrode patterning step of the present invention, the distance between the laser emission port and the irradiation surface, the laser diameter on the irradiation surface, the laser irradiation time, and the like are preferably appropriately selected according to the patterning shape and the like.
[0125]
In addition, in order to remove the residue of a surface electrode after performing the formation process of a photoelectric converting layer after the surface electrode patterning process in this invention, it is preferable to ultrasonically wash a board | substrate and a surface electrode in a pure water. .
[0126]
<Photoelectric Conversion Layer Formation Step: Step A>
In the method for producing a solar cell element of the present invention, in the step of forming two or more photoelectric conversion layers laminated on the surface electrode (also referred to as a photoelectric conversion layer formation step in this specification), a chemical production method is used. Or a physical manufacturing method can be used.
[0127]
Here, examples of the chemical manufacturing method in the photoelectric conversion layer forming step include a spray method, a CVD method, a plasma CVD method, and the like. In general, a chemical manufacturing method of a semiconductor is a method of forming a semiconductor film on a substrate by thermal decomposition of a source gas such as silane gas, plasma reaction, etc., and has an advantage that process cost is low.
[0128]
On the other hand, examples of the physical production method include a vacuum deposition method, an ion plating method, a sputtering method, and a magnetron sputtering method. In general, the physical manufacturing method has a lower substrate temperature than the chemical manufacturing method and can form a high-quality film, but has a tendency that the film forming speed is low and the cost of the apparatus is high.
[0129]
Of these manufacturing methods, the plasma CVD method is preferably used from the viewpoint of quality and the like.
[0130]
<First n-layer patterning step: B step>
Of the method for manufacturing a solar cell element of the present invention, a step of patterning a first n layer to form a first n layer separation line (also referred to as a first n layer patterning step in this specification). In the method, the patterning method is not particularly limited, and a method generally used for patterning of the photoelectric conversion layer and the transparent conductive film can be suitably used as long as it can be accurately patterned.
[0131]
In the patterning step of the photoelectric conversion layer in the present invention, for example, patterning by etching using a resin mask or a metal mask may be performed. However, such a method requires many processes for forming the laminated structure, and there are restrictions on the size of the substrate that can be handled, and the effective area of the power generation region in the substrate of the solar cell tends to be small, so that the wet process Therefore, pinholes are easily generated in the photoelectric conversion layer, and patterning is difficult on a curved substrate.
[0132]
Therefore, in the patterning step of the first n layer in the present invention, it is preferable to perform patterning using heating by laser irradiation (also referred to as laser patterning in this specification).
[0133]
By performing such laser patterning, the number of steps required for forming the laminated structure can be reduced, a solar cell element can be manufactured on a large-area substrate, and a substrate with an arbitrary shape such as a curved surface The solar cell element can be manufactured on the top, the effective area of the power generation region in the substrate of the solar cell can be increased, and there is an advantage that it is suitable for continuous integrated production and automated production.
[0134]
Here, in the patterning process of the first n layer in the present invention, the laser used for laser patterning is transparent in order to avoid damaging the transparent conductive film when the surface electrode is made of a transparent conductive film. It is preferable to use a laser in the visible light region where the conductive film has excellent transparency. Therefore, for example, it is preferable to use a YAG SHG laser.
[0135]
In the first n-layer patterning step of the present invention, the distance between the laser emission port and the irradiation surface, the laser irradiation time, and the like are preferably selected as appropriate in accordance with the patterning shape and the like.
[0136]
For example, when manufacturing a solar cell element as shown in FIG. 1, when forming the first n-layer separation line using the laser as described above, the first n-layer separation line is It is preferable to select the laser processing conditions so that the first n-layer and the member sandwiched between the first n-layer and the surface electrode penetrate to the surface on the back surface side of the surface electrode.
[0137]
For example, when manufacturing a solar cell element as shown in FIG. 2, when forming the first n-layer separation line using the laser as described above, the first n-layer separation line is It is preferable to select the laser processing conditions so as to partially remove the p layer and / or the i layer penetrating the first n layer and provided on the light incident side of the first n layer. In this case, the contact line described later needs to have a structure that completely separates the photoelectric conversion layer.
[0138]
After forming the first n-layer separation line, cleaning with pure water or the like may be performed, but if the first n-layer is cleaned with pure water or the like, the contact property between the first n-layer and the p-layer of the lower cell In this case, it is not necessary to perform cleaning with pure water or the like. In the present invention, since the residue of the surface electrode 2 is hardly generated when forming the first n-layer separation line, it is not necessary to perform cleaning with pure water or the like to remove the residue.
[0139]
<Further photoelectric conversion layer forming step: Step C>
In the method for manufacturing a solar cell element of the present invention, the first n-layer separation line separated by the first n-layer separation line by the above-described step and the first n-layer separation line include the first n-layer separation line. In the step of forming another photoelectric conversion layer so as to be in contact with the outer layer of the n-layer and the first n-layer separation line (also referred to as a further photoelectric conversion layer formation step in this specification) A manufacturing method or a physical manufacturing method can be used.
[0140]
Here, examples of the chemical manufacturing method in the photoelectric conversion layer forming step include a spray method, a CVD method, a plasma CVD method, and the like. In general, a chemical manufacturing method of a semiconductor is a method of forming a semiconductor film on a substrate by thermal decomposition of a source gas such as silane gas, plasma reaction, etc., and has an advantage that process cost is low.
[0141]
On the other hand, examples of the physical production method include a vacuum deposition method, an ion plating method, a sputtering method, and a magnetron sputtering method. In general, the physical manufacturing method has a lower substrate temperature than the chemical manufacturing method and can form a high-quality film, but has a tendency that the film forming speed is low and the cost of the apparatus is high.
[0142]
Of these manufacturing methods, the plasma CVD method is preferably used from the viewpoint of quality and the like.
[0143]
Further, only a part of the photoelectric conversion layer may be formed inside the first n-layer separation line, for example, only the semiconductor film provided on the most light incident side of the photoelectric conversion layer. May be.
[0144]
Further, the inside of the first n-layer separation line may be covered with a part of the photoelectric conversion layer entirely in the outline of the first n-layer separation line by the photoelectric conversion layer forming step. The inside of the first n-layer separation line may be filled with a part of the photoelectric conversion layer.
[0145]
Here, it is preferable that the A step, the B step, and the C step are sequentially performed in this order. By performing the A step, the B step, and the C step once, as shown in FIG. A solar cell element having two photoelectric conversion layers in which one power generation region is stacked with the first n layer interposed therebetween can be manufactured.
[0146]
<Contact line and back electrode forming process: D process>
Of the method for manufacturing a solar cell element of the present invention, the contact line forming step includes a step of forming an open groove (also referred to as an open groove of a contact line in this specification) necessary for forming the contact line, and a contact This can be divided into a process of filling the open groove of the line with a conductive material (in this specification, the material of the conductive material is referred to as the material of the contact line).
[0147]
Here, in the present invention, in the step of patterning the photoelectric conversion layer to form the contact line groove (also referred to as the contact line groove formation step in this specification), the patterning technique is particularly Any technique that is generally used for patterning the photoelectric conversion layer and the transparent conductive film can be suitably used as long as it is a technique that can be accurately patterned.
[0148]
In the contact line groove forming step of the present invention, patterning may be performed by etching using, for example, a resin mask or a metal mask. However, such a method requires many processes for forming the laminated structure, and there are restrictions on the size of the substrate that can be handled, and the effective area of the power generation region in the substrate of the solar cell tends to be small, so that the wet process Therefore, pinholes are easily generated in the photoelectric conversion layer, and patterning is difficult on a curved substrate.
[0149]
Therefore, it is preferable to perform laser patterning in the contact line groove forming step in the present invention. By performing such laser patterning, the number of steps required for forming the laminated structure can be reduced, a solar cell element can be manufactured on a large-area substrate, and a substrate with an arbitrary shape such as a curved surface The solar cell element can be manufactured on the top, the effective area of the power generation region in the substrate of the solar cell can be increased, and there is an advantage that it is suitable for continuous integrated production and automated production.
[0150]
Here, in the contact line groove forming step in the present invention, as the laser used for laser patterning, when the surface electrode is made of a transparent conductive film, the transparent conductive film is used to avoid damaging the transparent conductive film. It is preferable to use a laser in the visible light region that is excellent in film permeability. Therefore, for example, it is preferable to use a YAG SHG laser.
[0151]
The maximum diameter of the laser beam cross section used here is preferably smaller than the laser beam cross section used in the step B. If the maximum diameter of the laser beam cross section used here is larger than the laser beam cross section used in the B process, the first n layer separation is performed in the B process in order to separate the first n layer from the contact line. In order to form a line, a plurality of laser processings are essential, which reduces productivity.
[0152]
In the contact line groove forming step of the present invention, the distance between the laser emission port and the irradiated surface, the laser diameter on the irradiated surface, the laser processing conditions, and the like are appropriately selected according to the patterning shape and the like. Is preferred.
[0153]
However, regarding the laser processing conditions, the laser processing conditions are selected so that the groove of the contact line penetrates the member sandwiched between the back electrode and the front electrode and reaches the back surface of the front electrode. It is preferable.
[0154]
The contact line groove in the present invention is preferably provided inside the first n-layer separation line. That is, in the contact line groove forming step of the present invention, the cross section of the first n-layer separation line by a plane or curved surface parallel to the light-transmitting insulating substrate is the groove of the contact line line by the plane or curved surface. It is preferable to perform laser patterning with a laser aiming at a position that includes the cross section.
[0155]
<Contact line filling and back electrode forming process>
Of the method for manufacturing a solar cell element of the present invention, the conductive material used in the step of filling the open grooves of the contact line with the conductive material (also referred to as the contact line filling step in this specification) has conductivity. If it is, it will not specifically limit, The electrically conductive substance generally used for a solar cell element can be used.
[0156]
In addition, when a back surface electrode consists of a back surface metal electrode and a back surface transparent electrode, it is preferable to use the electrically conductive material which consists of the same material as said back surface transparent electrode from a viewpoint of simplification of a manufacturing process.
[0157]
Therefore, the contact line filling step in the present invention is preferably the same step as the step of forming the back transparent electrode in the back electrode forming step. By performing the contact line filling process, it is desirable that the inside of the contact line is completely filled with the conductive material, and the front electrode and the back electrode are completely electrically connected.
[0158]
In the method for manufacturing a solar cell element of the present invention, the step of forming the back electrode (also referred to as a back electrode forming step in this specification) differs depending on the material and structure of the back electrode.
[0159]
Here, as described above, the back electrode used in the present invention is preferably a laminate of a back transparent electrode and a back metal electrode. In addition, the back electrode used in the present invention may be composed only of the back metal electrode, and the back transparent electrode may be omitted, but in order to promote light scattering and obtain high power generation efficiency, It is desirable to have a transparent electrode.
[0160]
And as a manufacturing method of the back surface metal electrode used for this invention, it is preferable to use a physical manufacturing method. Examples of the physical production method include a vacuum deposition method, an ion plating method, a sputtering method, and a magnetron sputtering method. Of these manufacturing methods, it is preferable to use a sputtering method in terms of quality and the like.
[0161]
Moreover, as a manufacturing method of the back surface transparent electrode used for this invention, a chemical manufacturing method or a physical manufacturing method can be used.
[0162]
Here, examples of the chemical manufacturing method include a spray method, a CVD method, and a plasma CVD method. In general, the chemical production method is a method of forming an oxide film on a substrate by thermal decomposition or oxidation reaction of chloride or an organometallic compound, and has an advantage that process cost is low.
[0163]
On the other hand, examples of the physical production method include a vacuum deposition method, an ion plating method, a sputtering method, and a magnetron sputtering method. In general, the physical manufacturing method has a lower substrate temperature than the chemical manufacturing method and can form a high-quality film, but has a tendency that the film forming speed is low and the cost of the apparatus is high.
[0164]
Of these manufacturing methods, it is preferable to use a sputtering method in terms of quality and the like.
[0165]
<Back electrode patterning process>
In the method for manufacturing a solar cell element of the present invention, the patterning method is particularly limited in the step of patterning the back electrode to form the back electrode separation line (also referred to as back electrode patterning step in this specification). Any technique that can be used for patterning a metal electrode or a transparent conductive film can be suitably used as long as it can be accurately patterned.
[0166]
In the back electrode patterning step in the present invention, for example, patterning by etching using a resin mask, a metal mask or the like may be performed. However, such a method requires many processes for forming the laminated structure, and there are restrictions on the size of the substrate that can be handled, and the effective area of the power generation region in the substrate of the solar cell tends to be small, so that the wet process Therefore, pinholes are easily generated in the photoelectric conversion layer, and patterning is difficult on a curved substrate.
[0167]
Therefore, it is preferable to perform laser patterning in the back electrode patterning step in the present invention. By performing such laser patterning, the number of steps required for forming the laminated structure can be reduced, a solar cell element can be manufactured on a large-area substrate, and a substrate with an arbitrary shape such as a curved surface The solar cell element can be manufactured on the top, the effective area of the power generation region in the substrate of the solar cell can be increased, and there is an advantage that it is suitable for continuous integrated production and automated production.
[0168]
Here, in the back surface electrode patterning step in the present invention, as a laser used for laser patterning, in order to avoid adversely affecting the surface electrode made of the transparent conductive film, a visible light region excellent in transparency of the transparent conductive film is used. It is preferable to use a laser. For example, it is preferable to use a YAG SHG laser.
[0169]
In the back electrode patterning step of the present invention, the distance between the laser emission port and the irradiated surface, the laser diameter on the irradiated surface, the laser processing conditions, and the like are preferably selected as appropriate according to the patterning shape and the like.
[0170]
In addition, it is preferable to ultrasonically wash a board | substrate and a surface electrode in a pure water after the back surface electrode patterning process in this invention.
[0171]
And the solar cell element of this invention manufactured using said manufacturing method is used suitably as a main member of a solar cell individually or in combination of several or in combination with another solar cell element.
[0172]
【Example】
EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated in detail, this invention is not limited to these.
[0173]
<Example 1>
Hereinafter, Example 1 will be described with reference to FIG. Here, FIG. 1 is a schematic cross-sectional view of the solar cell element produced in Example 1. FIG.
[0174]
First, a glass substrate having a thickness of about 4.0 mm and a substrate size of 650 mm × 910 mm is prepared as the insulating translucent substrate 1, and SnO is formed on the insulating translucent substrate 1 using a thermal CVD method. ₂ A surface electrode 2 made of a transparent conductive film made of (tin oxide) was formed.
[0175]
Next, the surface electrode 2 was patterned using the fundamental wave of the YAG laser. That is, the surface electrode 2 was separated into strips by making laser light incident from the insulating translucent substrate 1 side, and the surface electrode separation line 6 was formed.
[0176]
Thereafter, the substrate is ultrasonically cleaned in pure water, and then an upper cell 3 made of a photoelectric conversion layer in which a semiconductor film is laminated on the surface electrode 2 and inside the surface electrode separation line 6 is formed by plasma CVD. did. Here, the upper cell 3 formed as described above has an insulating translucency for the p layer made of a-Si: H, the i layer made of a-Si: H, and the n layer made of μc-Si: H. The photoelectric conversion layers were laminated in order from the substrate 1 side, and the total thickness was about 0.2 μm.
[0177]
Subsequently, the upper cell 3 was patterned by allowing the second harmonic of the YAG laser to enter from the insulating translucent substrate 1 side. As a result, the upper cell 3 was separated into strips, and a first n-layer separation line 7 extending through the upper cell 3 to the surface on the back surface side of the surface electrode 2 was formed. At this time, as shown in FIG. 3, the width 15 of the first n-layer separation line was set to about 150 μm.
[0178]
Next, the lower cell 4 made of a photoelectric conversion layer in which a semiconductor film was stacked was formed inside the first n-layer separation line 7 by plasma CVD. Here, in the lower cell 4 formed as described above, the p layer made of μc-Si: H, the i layer made of μc-Si: H, and the n layer made of μc-Si: H were insulated and translucent. The photoelectric conversion layers were laminated in order from the substrate 1 side, and the total thickness was about 2 μm.
[0179]
Next, the second harmonic of the YAG laser was made incident from the insulating translucent substrate 1 side, and the lower cell 4 was patterned. As a result, the lower cell 4 was separated into strips, and an open groove of the contact line 8 for electrically connecting the front electrode 2 and the back electrode 5 was formed.
[0180]
At this time, as can be seen with reference to FIG. 3, when the back electrode 5 is formed without making the width 13 of the contact line smaller than the width 15 of the first n-layer separation line, the back electrode as shown in FIG. 5 is in direct contact with the first n layer 3b. As a result, there is a problem that the upper cell 3 is short-circuited and the output of the solar cell element is less than the original output.
[0181]
Therefore, in this embodiment, as shown in FIG. 3, the groove of the contact line 8 is formed so that the width 13 of the contact line is smaller than the width 15 of the first n-layer separation line.
[0182]
By reducing the width 13 of the contact line, the first n layer / contact line isolation member made of the material having the same composition as that of the lower cell 4 fills a part of the first n layer separation line 7. The conductive material filled in the groove of the contact line 8 made of the material having the same composition as that of the first n layer 3b and the back electrode can be separated, and as a result, the upper cell 3 can be prevented from being short-circuited. did it.
[0183]
At this time, the width 13 of the contact line was set to about 80 μm, and the distance 17a between the first n-layer separation line and the contact line was set to about 50 μm. Further, the distance 17b between the first n-layer separation line and the contact line on the side opposite to the distance 17a between the first n-layer separation line and the contact line was set to about 20 μm.
[0184]
Next, a film of ZnO (zinc oxide) and Ag was formed as the back electrode 5 by magnetron sputtering. At this time, the total thickness of the back electrode 5 was about 350 nm. At this time, the inner side of the groove of the contact line 8 is filled with a material having the same composition as the back electrode 5.
[0185]
And in order to avoid the damage to the surface electrode 2 by a laser, the 2nd harmonic of the YAG laser with the sufficient transparency of the surface electrode 2 was entered from the insulated translucent board | substrate 1 side, and the back surface electrode 5 was patterned. As a result, the back electrode 5 was separated into strips, and a back electrode separation line 9 was formed. Thereafter, the substrate was subjected to ultrasonic cleaning in pure water, and after drying, a bus bar was attached to the positive electrode and the negative electrode to produce a solar cell element (I) of this example.
[0186]
When the characteristics of the solar cell element (I) produced as described above (substrate size: 650 mm × 910 mm) were evaluated using a solar simulator, AM1.5 (100 mW / cm ² ) Measured under the conditions of F.). F. Is 0.67 to 0.70, η _n A stable efficiency of 10.3% to 11.0% was obtained.
[0187]
<Example 2>
The first n-layer separation line 7 has a structure that does not reach the back surface side of the front electrode, and is opposite to the insulating translucent substrate 1 so that the shape of the tip of the first n-layer separation line 7 is a curved surface. A solar cell element was fabricated in the same manner as in Example 1 except that laser patterning was performed on the first n-layer separation line 7 by irradiating the laser from the side, and a solar cell element (II) was obtained. It was.
[0188]
When the characteristics of the solar cell element (II) (substrate size 650 mm × 910 mm) produced as described above were evaluated using a solar simulator, AM1.5 (100 mW / cm ² ) Measured under the conditions of F.). F. Is 0.67 to 0.70, η _n A stable efficiency of 10.3% to 11.0% was obtained.
[0189]
<Comparative Example 1>
Hereinafter, Comparative Example 1 will be described with reference to FIG. Here, FIG. 5 is a schematic cross-sectional view of the solar cell element produced in Comparative Example 1. FIG. Further, this solar cell element has the same structure as the integrated structure disclosed in JP-A-9-129903.
[0190]
First, a glass substrate having a thickness of about 4.0 mm and a substrate size of 650 mm × 910 mm is prepared as the insulating translucent substrate 1, and SnO is formed on the insulating translucent substrate 1 using a thermal CVD method. ₂ A surface electrode 2 made of a transparent conductive film made of (tin oxide) was formed.
[0191]
Next, an upper cell 3 made of a photoelectric conversion layer in which a semiconductor film was stacked on the surface electrode 2 was formed by a plasma CVD method. Here, the upper cell 3 formed as described above has an insulating translucency for the p layer made of a-Si: H, the i layer made of a-Si: H, and the n layer made of μc-Si: H. The photoelectric conversion layers were laminated in order from the substrate 1 side, and the total thickness was about 0.2 μm.
[0192]
Thereafter, patterning of the surface electrode 2 and the upper cell 3 was performed at once using the fundamental wave of the YAG laser. That is, the surface electrode 2 and the upper cell 3 were separated into strips by making laser light incident from the insulating translucent substrate 1 side, and the surface electrode separation line 6 was formed.
[0193]
Subsequently, the substrate was ultrasonically cleaned with pure water, and the lower cell 4 made of a photoelectric conversion layer in which a semiconductor film was laminated was formed inside the surface electrode separation line 6 by a plasma CVD method. Here, in the lower cell 4 formed as described above, the p layer made of μc-Si: H, the i layer made of μc-Si: H, and the n layer made of μc-Si: H were insulated and translucent. The photoelectric conversion layers were laminated in order from the substrate 1 side, and the total thickness was about 2 μm.
[0194]
Next, the upper cell 3 and the lower cell 4 were patterned by allowing the second harmonic of the YAG laser to enter from the insulating translucent substrate 1 side. As a result, the upper cell 3 and the lower cell 4 are separated into strips, penetrate the upper cell 3 and the lower cell 4 to reach the surface on the back surface side of the surface electrode 2, and connect the surface electrode 2 and the back electrode 5 to each other. An open groove of the contact line 8 for electrical connection was formed.
[0195]
Next, a film of ZnO (zinc oxide) and Ag was formed as the back electrode 5 by magnetron sputtering. At this time, the total thickness of the back electrode 5 was about 350 nm. At this time, the inner side of the groove of the contact line 8 is filled with a material having the same composition as the back electrode 5.
[0196]
Next, in order to avoid damage to the surface electrode 2 due to the laser, the second harmonic of the YAG laser having good transparency of the surface electrode 2 was made incident from the insulating translucent substrate 1 side, and the back electrode 5 was patterned. As a result, the back electrode 5 was separated into strips, and a back electrode separation line 9 was formed. Thereafter, the substrate was subjected to ultrasonic cleaning in pure water, and after drying, a bus bar was attached to the positive electrode and the negative electrode to produce a solar cell element (III) of this comparative example.
[0197]
The characteristics of the solar cell element (III) (substrate size 650 mm × 910 mm) produced as described above were evaluated using a solar simulator. F. Is 0.58 to 0.70 and η _n An efficiency of 7.9% to 11.0% was obtained.
[0198]
As can be seen from the reason for the variation in this value, the surface electrode separation line 6 of the solar cell element (III) produced in Comparative Example 1 is subjected to laser patterning for the surface electrode 2 and the upper cell 3 collectively. Therefore, even if the surface electrode 2 can be completely separated between adjacent power generation regions, the sublimated surface electrode 2 is reattached to the side surface of the upper cell 3, and the first n layer 3b and the surface It is understood that this is because short-circuiting between the electrodes 2 tends to occur at a high frequency. That is, as a result, it is understood that the upper cell 3 is short-circuited and the output of the solar cell element is reduced.
[0199]
Further, in the region where the lower cell was directly formed on the glass substrate, a part of the film was peeled off, and there was a problem in appearance, and in such a cell, the characteristics were deteriorated.
[0200]
It should be understood that the embodiments and examples disclosed herein are illustrative and non-restrictive in every respect. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.
[0201]
【The invention's effect】
As can be seen from the above results, the solar cell element of the present invention includes a single member or a plurality of members made of a nonconductor and / or a semiconductor between the first n layer and the contact line, and the first n layer. And the contact line are not in direct contact with each other, so that a short circuit does not occur between the first n layer and the contact line.
[0202]
Moreover, since the lower cell and the insulating translucent substrate are not in direct contact with the solar cell element of the present invention, the lower cell is hardly peeled off. Furthermore, since cleaning with pure water after the formation process of the first n-layer separation line is unnecessary, the contact property between the first n-layer and the lower cell is excellent. The power generation efficiency of the solar cell element is excellent.
[0203]
That is, it can be said that the solar cell element of the present invention is a solar cell element having a series laminated structure that is excellent in power generation efficiency per unit area and can be manufactured with high reliability and yield.
[0204]
Moreover, the method for manufacturing a solar cell element of the present invention is a method for manufacturing a solar cell element capable of manufacturing a solar cell element having a series laminated structure excellent in power generation efficiency per unit area with high reliability and yield. I can say that.
[Brief description of the drawings]
1 is a schematic cross-sectional view of a solar cell element produced in Example 1 of the present invention.
FIG. 2 is a schematic cross-sectional view of a solar cell element produced in Example 2 of the present invention.
FIG. 3 is an enlarged schematic cross-sectional view showing the vicinity of a contact line of a solar cell element manufactured in Example 1 of the present invention.
FIG. 4 is a schematic cross-sectional view of an example of a conventionally known general series stacked solar cell element.
5 is a schematic cross-sectional view of a solar cell element produced in Comparative Example 1. FIG.
FIG. 6 is a schematic cross-sectional view of a solar cell element disclosed in JP-A-9-129906.
FIG. 7 is a schematic cross-sectional view of another example of the solar cell element of the present invention.
[Explanation of symbols]
1 insulating translucent substrate, 2 surface electrode, 3 upper cell, 3a first p layer and i layer, 3b first n layer, 4 lower cell, 4a second p layer and i layer, 4b second n layer, 5 back electrode, 6 surface electrode separation line, 7 first n layer separation line, 8 contact line, 9 back electrode separation line, 13 contact line width, 15 first n layer separation line width, 17a , 17b Distance between the first n-layer separation line and the contact line, 18 First n-layer / contact line isolation member, 23 Third photoelectric conversion layer, 25 First n-layer and second n-layer separation line 38 Surface electrode / first n-layer isolation member.

Claims (8)

At least the insulative transparent substrate, a power generation region having a surface electrode, a photoelectric conversion layer and the back surface electrode formed by laminating a semiconductor film, the back surface electrode integrally for electrically connecting the surface electrode and the back electrode of the power generation region adjacent to a configured contact line, a solar cell element in which a plurality of power generation regions are connected in series, the power generation region, at least a first p-layer, i layer, a photoelectric conversion layer consisting of n layers , A second p layer, an i layer, and a photoelectric conversion layer composed of an n layer are sequentially stacked, and the first n layer is a semiconductor film containing microcrystalline silicon, Between the n layer and the contact line, a single member or a plurality of members made of a nonconductor and / or a semiconductor integrated with a photoelectric conversion layer provided on the back side of the first n layer is provided. Contact with the first n-layer Solar cell element and having a structure that does not contact directly with Inn. At least the insulative transparent substrate, a power generation region having a surface electrode, a photoelectric conversion layer and the back surface electrode formed by laminating a semiconductor film, the back surface electrode integrally for electrically connecting the surface electrode and the back electrode of the power generation region adjacent to a configured contact line, a solar cell element in which a plurality of power generation regions are connected in series, the power generation region, at least a first p-layer, i layer, a photoelectric conversion layer consisting of n layers , The second p layer, the i layer, and the n-layer photoelectric conversion layer are sequentially stacked, and the first n layer is a semiconductor film containing microcrystalline silicon, Between the n layer and the contact line, a portion integrally formed with the photoelectric conversion layer provided on the light incident side with respect to the first n layer, and provided on the back side with respect to the first n layer was nonconducting to a photoelectric conversion layer and the portion which is integrally formed is combined And / or provided with a single or plurality of members made of a semiconductor, the solar cell element and having a structure that does not contact directly with said first n-layer and the contact line. Single or consisting of a nonconductor and / or a semiconductor integrated with a photoelectric conversion layer provided on the back side of the first n layer provided between the first n layer and the contact line 2. The solar cell element according to claim 1, wherein the plurality of members are members made of a material having the same composition as a part of the photoelectric conversion layer provided on the back surface side of the first n layer. . A portion integrally formed with the photoelectric conversion layer provided on the light incident side of the first n layer provided between the first n layer and the contact line; and from the first n layer A single member or a plurality of members made of a non-conductor and / or a semiconductor in which a photoelectric conversion layer provided on the back surface side and a portion integrally formed are combined are closer to the light incident side than the first n layer. A part made of a material having the same composition as a part of the provided photoelectric conversion layer and a part made of a material having the same composition as a part of the photoelectric conversion layer provided on the back side of the first n layer The solar cell element according to claim 2, wherein the solar cell element is a composite member.   Among the photoelectric conversion layers, the first i layer is a semiconductor film mainly made of amorphous silicon, and the second i layer is a semiconductor film mainly made of microcrystalline silicon. The solar cell element according to any one of claims 1 to 4. Among the photoelectric conversion layers, the first p layer and the i layer are semiconductor films whose main material is a-Si: H, and the first n layer is a material whose main material is μc-Si: H. a semiconductor film, the second p-layer, i layer and n-layer [mu] c-Si: according to any one of claims 1 to 4, characterized in that a semiconductor film for a major material of H Solar cell element. It is a manufacturing method of the solar cell element in any one of Claims 1-6 , Comprising: As 1st p layer, i layer, n layer in order as A process, and 1st as B process Forming a first n-layer separation line that penetrates through the n-layer and a member sandwiched between the first n-layer and the surface electrode to reach the surface on the back surface side of the surface electrode, A second p-layer and an i-layer in contact with the outer surface of the first n-layer and the first n-layer separation line, on the back side of the first n-layer and in the first n-layer separation line The step of forming the n layer in sequence, and the step D include a step of forming a contact line groove extending through the member sandwiched between the back electrode and the surface electrode and reaching the surface on the back surface side of the surface electrode, A cross section of the first n-layer separation line by a plane or curved surface parallel to the translucent insulating substrate is determined by the plane or curved surface. A method for manufacturing a solar cell element comprising a cross section of an open groove of the contact line. It is a manufacturing method of the solar cell element in any one of Claims 1-6 , Comprising: As a A process, the process of forming a 1st p layer, i layer, and n layer in order; Forming a first n-layer separation line that penetrates the n-layer and partially removes the first p-layer and / or i-layer, and as a C-step, the back side of the first n-layer Forming a second p-layer, an i-layer, and an n-layer in this n-layer separation line in order so as to be in contact with the outline of the first n-layer and the first n-layer separation line; The process includes forming a contact line groove extending through the member sandwiched between the back electrode and the front electrode to reach the back surface of the front electrode, and is a plane or curved surface parallel to the translucent insulating substrate The cross section of the first n-layer separation line according to FIG. A method for producing a solar cell element comprising a surface.

Images