KR101368903B1 - Thin film type Solar Cell, and Method for manufacturing the same - Google Patents

Abstract

The present invention provides a method of forming a plurality of unit front electrodes spaced apart at predetermined intervals on a substrate; Forming a semiconductor layer on the entire surface of the substrate; Forming a plurality of unit semiconductor layers spaced apart from each other by interposing the contact portion and the separation portion by irradiating a laser beam to the semiconductor layer; And forming a plurality of unit back electrodes connected to the unit front electrode through the contact part and spaced apart by the separating part, wherein the contact part and the separating part are simultaneously irradiated with one laser beam. A method of manufacturing a thin film solar cell, and a thin film solar cell manufactured by the method,

According to the present invention, in the process of forming the contact portion and the separation portion by the laser scribing process, the laser beam emitted from one laser oscillator is divided into a plurality of laser beams and irradiated or the laser beam emitted from one laser oscillator By changing the profile of and irradiating a laser beam having a plurality of beam spots, the contact portion and the separation portion can be formed simultaneously, thereby reducing the number of laser scribing processes.

Thin film solar cell, laser scribing

Description

Thin film type solar cell and its manufacturing method {Thin film type Solar Cell, and Method for manufacturing the same}

The present invention relates to a thin film solar cell, and more particularly, to a thin film solar cell having a structure in which a plurality of unit cells are connected in series.

Solar cells are devices that convert light energy into electrical energy using the properties of semiconductors.

The structure and principle of a solar cell will be briefly described. A solar cell has a PN junction structure in which a P (positive) semiconductor and an N (negative) semiconductor are bonded. When solar light enters the solar cell having such a structure, Holes and electrons are generated in the semiconductor due to the energy of the incident sunlight. At this time, the holes (+) move toward the P-type semiconductor due to the electric field generated at the PN junction, (-) is moved toward the N-type semiconductor to generate electric potential, thereby generating electric power.

Such a solar cell can be classified into a substrate type solar cell and a thin film type solar cell.

The substrate type solar cell is a solar cell manufactured using a semiconductor material itself such as silicon as a substrate, and the thin film type solar cell is formed by forming a semiconductor in the form of a thin film on a substrate such as glass to manufacture a solar cell.

Although the substrate type solar cell has a somewhat higher efficiency than the thin film type solar cell, there is a limitation in minimizing the thickness in the process, and a manufacturing cost is increased because an expensive semiconductor substrate is used.

Though the efficiency of the thin-film solar cell is somewhat lower than that of the substrate-type solar cell, the thin-film solar cell can be manufactured in a thin thickness and can be made of a low-cost material.

The thin-film solar cell is manufactured by forming a front electrode on a substrate such as glass, forming a semiconductor layer on the front electrode, and forming a rear electrode on the semiconductor layer. Since the front electrode forms a light receiving surface on which light is incident, a transparent conductive material such as ZnO is used as the front electrode. As the substrate becomes larger, the power loss due to the resistance of the transparent conductive material increases .

Therefore, a method has been devised in which a thin film solar cell is divided into a plurality of unit cells and a plurality of unit cells are connected in series so as to minimize the power loss due to the resistance of the transparent conductive material.

Hereinafter, a method of manufacturing a thin film solar cell having a plurality of unit cells connected in series will be described with reference to the drawings.

1A to 1F are cross-sectional views illustrating a conventional manufacturing process of a thin film solar cell having a plurality of unit cells connected in series.

First, as shown in FIG. 1A, the front electrode layer 12a is formed on the substrate 10 using a transparent conductive material such as ZnO.

Next, as shown in FIG. 1B, the front electrode layer 12a is patterned to form a unit front electrode 12. The patterning process of the front electrode layer 12a is performed using a laser scribing process.

Next, as shown in FIG. 1C, the semiconductor layer 14a is formed on the entire surface of the substrate 10. The semiconductor layer 14a is formed using a semiconductor material such as silicon, and has a so-called PIN structure stacked with a P-type semiconductor layer, an I-type (Intrinsic) semiconductor layer, and an N-type semiconductor layer.

Next, as shown in FIG. 1D, the semiconductor layer 14a is patterned to form a unit semiconductor layer 14. The patterning process of the semiconductor layer 14a is performed using a laser scribing process.

Next, as can be seen in Figure 1e, the back electrode layer 20a is formed on the entire surface of the substrate 10.

Next, as can be seen in Figure 1f, the back electrode layer 20a is patterned to form a unit back electrode 20. Here, when the back electrode layer 20a is patterned, the unit semiconductor layer 14 below is also patterned. The patterning process is performed by using a laser scribing process.

However, such a conventional method of manufacturing a thin film solar cell has the following problems.

First, the patterning process of the front electrode layer 12a (see FIG. 1B), the patterning process of the semiconductor layer 14a (see FIG. 1D), and the patterning process of the back electrode layer 20a (see FIG. 1F) are performed. Since the patterning process needs to be performed three times, the process becomes complicated.

Second, since all three patterning processes are performed by using a laser scribing process, residues generated during the laser scribing process may remain on the substrate, thereby increasing the risk of contamination of the substrate and preventing contamination of the substrate. In order to add a cleaning process, there is a problem that the process is complicated and productivity is reduced.

The present invention has been devised to solve the problems of the conventional thin film type solar cell,

An object of the present invention is to provide a thin-film solar cell and a method of manufacturing the same that can be manufactured by a simpler method by shortening the patterning process.

The present invention provides a thin-film solar cell and a method of manufacturing the same which can increase productivity by reducing the number of times of use of the laser scribing process in performing the patterning process and reducing the possibility of contamination of the substrate and the cleaning process. The purpose.

The present invention to achieve the above object, the step of forming a plurality of unit front electrode spaced at a predetermined interval on the substrate; Forming a plurality of unit semiconductor layers spaced apart from each other with a predetermined open portion on the unit front electrode; And forming a plurality of unit back electrodes spaced apart from each other via the open portion and spaced apart from each other with the remaining portion of the open portion interposed therebetween.

The present invention also provides a process for forming a plurality of unit front electrodes spaced at predetermined intervals on a substrate; Forming a semiconductor layer on the entire surface of the substrate; Forming a plurality of unit semiconductor layers spaced apart from each other by interposing a predetermined contact portion and a separation portion in the semiconductor layer; And forming a plurality of unit back electrodes connected to the unit front electrode through the contact unit and spaced apart from the separation unit.

The contact part and the separation part may be simultaneously formed through a process of irradiating a laser beam once.

In the step of irradiating the laser beam, the contact part and the separation part may be simultaneously formed by one laser beam irradiation by dividing and irradiating a laser beam emitted from one laser oscillator into a plurality of laser beams.

The process of irradiating the laser beam is performed using a predetermined laser scribing equipment, the laser scribing equipment comprising a laser oscillator; A first mirror to which a laser beam emitted from the laser oscillator is incident, which passes a portion of the incident laser beam and reflects the remainder of the incident laser beam; A second mirror reflecting all of the laser beams reflected from the first mirror; A first lens to which the laser beam passing through the first mirror is incident; And a second lens into which the laser beam reflected from the second mirror is incident.

The process of irradiating the laser beam is performed using a predetermined laser scribing equipment, the laser scribing equipment comprising a laser oscillator; A first mirror to which a laser beam emitted from the laser oscillator is incident, which passes a portion of the incident laser beam and reflects the remainder of the incident laser beam; A second mirror reflecting all of the laser beams reflected from the first mirror; A third mirror passing through a portion of the laser beam passing through the first mirror and reflecting a portion of the laser beam passing through the first mirror; A fourth mirror reflecting all of the laser beams reflected from the third mirror; A fifth mirror passing through a portion of the laser beam reflected from the second mirror and reflecting a portion of the laser beam reflected from the second mirror; A sixth mirror reflecting all of the laser beam reflected from the fifth head; A first lens into which the laser beam passing through the third mirror is incident; A second lens into which the laser beam reflected from the fourth mirror is incident; A third lens into which the laser beam passing through the fifth mirror is incident; And a fourth lens into which the laser beam reflected from the sixth mirror is incident.

The irradiating of the laser beam may simultaneously form the contact portion and the separating portion by one laser beam irradiation by changing a profile of the laser beam emitted from one laser oscillator and irradiating a laser beam having a plurality of beam spots. Can be.

The process of irradiating the laser beam may be performed using a predetermined laser scribing equipment, and the laser scribing equipment may include a laser oscillator, a beam shaper, and a lens.

The forming of the unit front electrode may be performed by forming a front electrode layer on the substrate and patterning the front electrode layer by irradiating a laser beam to the front electrode layer.

The unit front electrode may be formed by screen printing, inkjet printing, gravure printing, or microcontact printing.

The process of forming the unit back electrode may be performed using a screen printing method, an inkjet printing method, a gravure printing method, or a microcontact printing method.

The method may further include forming a unit transparent conductive layer having the same pattern as the unit semiconductor layer on the unit semiconductor layer.

The present invention also provides a plurality of unit front electrodes spaced apart at predetermined intervals on the substrate; A plurality of unit semiconductor layers formed on the unit front electrode and spaced apart from each other with a predetermined opening; And a plurality of unit back electrodes connected to the unit front electrode through a part of the open part and spaced apart from each other with the remaining part of the open part interposed therebetween.

The present invention also provides a plurality of unit front electrodes spaced apart at predetermined intervals on the substrate; A plurality of unit semiconductor layers spaced apart from each other on the unit front electrode with a predetermined contact portion and a separation portion therebetween; It provides a thin film type solar cell connected to the unit front electrode through the contact portion, comprising a plurality of unit back electrodes spaced apart by the separation unit.

A unit transparent conductive layer having the same pattern as the unit semiconductor layer may be further formed on the unit semiconductor layer.

According to the present invention as described above, the following effects can be obtained.

First, the present invention can reduce the laser scribing process to two times or less, which simplifies the process, and reduces the problem of substrate contamination caused by the laser scribing process and the problem of reduced productivity due to the increase of the cleaning process. .

Secondly, in the process of forming a contact portion and a separation portion by a laser scribing process, the laser beam emitted from one laser oscillator is divided into a plurality of laser beams and irradiated or a laser beam emitted from one laser oscillator By changing the profile of and irradiating a laser beam having a plurality of beam spots, the contact portion and the separation portion can be formed simultaneously, thereby reducing the number of laser scribing processes.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.

<Thin Film Solar Cell Manufacturing Method>

2A to 2F are cross-sectional views illustrating a manufacturing process of a thin film solar cell according to an embodiment of the present invention.

First, as shown in FIG. 2A, the front electrode layer 120a is formed on the substrate 100.

Glass or transparent plastic may be used as the substrate 100.

The front electrode layer 120a may be formed by sputtering or MOCVD (Metal Organic Chemical Vapor) using a transparent conductive material such as ZnO, ZnO: B, ZnO: Al, SnO ₂ , SnO ₂ : F, Indium Tin Oxide (ITO), or the like. It can be formed using a deposition method and the like.

Since the front electrode layer 120a is a surface on which solar light is incident, it is important to allow the incident sunlight to be absorbed to the inside of the solar cell as much as possible. For this purpose, a texturing process is applied to the front electrode layer 120a. It can be done further.

The texturing process is a process in which the material surface is formed into a rugged concavo-convex structure so as to be processed into the same shape as the surface of the fabric. An etching process using photolithography, anisotropic etching using a chemical solution, , Or a groove forming process using mechanical scribing, or the like. When such a texture processing process is performed on the front electrode layer 120a, the ratio of incident solar light reflected to the outside of the solar cell is reduced, and sunlight is emitted into the solar cell by scattering of incident sunlight. The rate of absorption is increased, thereby increasing the efficiency of the solar cell.

Next, as shown in FIG. 2B, the front electrode layer 120a is patterned to form a plurality of unit front electrodes 120 spaced at predetermined intervals.

The patterning process of the front electrode layer 120a may be performed using a laser scribing process.

2A and 2B, instead of forming the front electrode layer 120a on the entire surface of the substrate 100 and patterning the unit front electrode 120 using a laser scribing process, screen printing is performed. Forming the unit front electrode 120 directly on the substrate 100 using a simpler method such as inkjet printing, gravure printing or microcontact printing. It is possible.

The screen printing method is a method of forming a predetermined pattern by transferring a target material to a work using a screen and a squeeze. In the inkjet printing method, an object is sprayed onto a work using an inkjet, The gravure printing method is a method of applying a target material to a groove of a concave plate and transferring the target material to a workpiece again to form a predetermined pattern. The fine contact printing method is a method of forming a predetermined mold To form a target material pattern on a workpiece.

As such, when the unit front electrode 120 is formed by screen printing, inkjet printing, gravure printing, or microcontact printing, the substrate is less likely to be contaminated than the laser scribing process. The cleaning process to prevent contamination of the process is also reduced.

Next, as shown in FIG. 2C, the semiconductor layer 140a is formed on the entire surface of the substrate 100. As illustrated, the semiconductor layer 140a is formed on the space between the unit front electrodes 120 spaced apart from each other, and on the unit front electrode 120.

The semiconductor layer 140a may be formed of a silicon-based semiconductor material using a plasma CVD method or the like.

The semiconductor layer 140a may be formed in a PIN structure in which a P-type semiconductor layer, an I-type semiconductor layer, and an N-type semiconductor layer are sequentially stacked. When the semiconductor layer 140a is formed in the PIN structure as described above, the I-type semiconductor layer is depleted by the P-type semiconductor layer and the N-type semiconductor layer to generate an electric field therein, and is caused by sunlight. The generated holes and electrons are drift by the electric field and are collected in the P-type semiconductor layer and the N-type semiconductor layer, respectively.

On the other hand, when the semiconductor layer 140a is formed in a PIN structure, it is preferable to form a P-type semiconductor layer on the unit front electrode 120 and then form an I-type semiconductor layer and an N-type semiconductor layer. This is because the drift mobility of holes is generally low due to the drift mobility of electrons, so that the P-type semiconductor layer is formed close to the light receiving surface in order to maximize collection efficiency by incident light.

Next, as shown in FIG. 2D, a transparent conductive layer 160a is formed on the semiconductor layer 140a.

The transparent conductive layer 160a may be formed of a transparent conductive material such as ZnO, ZnO: B, ZnO: Al, Ag by using a sputtering method or a metal organic chemical vapor deposition (MOCVD) method.

Although the process of forming the transparent conductive layer 160a may be omitted, it is preferable to form the transparent conductive layer 160a in order to increase efficiency of the solar cell. That is, when the transparent conductive layer 160a is formed, sunlight passing through the semiconductor layer 140a passes through the transparent conductive layer 160a and progresses through scattering at various angles, and is reflected from the rear electrode layer to be described later. This is because the proportion of light reincident to 140a can be increased.

Next, as can be seen in FIG. 2E, the semiconductor layer 140a and the transparent conductive layer 160a are simultaneously patterned, and the plurality of unit semiconductor layers 140 and unit transparency spaced apart with a predetermined open portion 171 therebetween. The entire layer 160 is formed.

The patterning process of the semiconductor layer 140a and the transparent conductive layer 160a may be performed using a laser scribing process.

Next, as can be seen in FIG. 2F, a plurality of unit back electrodes 180 connected to the unit front electrode 120 are formed through the open part 171.

In this case, the unit back electrode 180 is connected to the unit front electrode 120 through a part of the open part 171, and the remaining part of the open part 171 is separated to separate the solar cell into the unit cell. It functions as the unit 172, and the plurality of unit back electrodes 180 are spaced apart from each other with the separation unit 172 interposed therebetween.

The unit back electrode 180 is performed by screen printing, inkjet printing, gravure printing, or microcontact printing. Metals such as Ag, Al, Ag + Mo, Ag + Ni, Ag + Cu and the like are used.

2A to 2F, the laser scribing process can be reduced to two times or less, thereby simplifying the process and reducing the contamination of the substrate due to the laser scribing process.

Meanwhile, the unit back electrode 180 formed in the process of FIG. 2F should be formed only on a part of the open part 171 as the separator 172 separating the solar cell into the unit cell. If the unit back electrode 180 is formed on all of the open parts 171 due to a process error, a short may occur between unit cells of the solar cell. That is, as can be seen in Figure 3, when the unit back electrode 180, which should be formed only in a part of the open portion 171 flows to the remaining portion of the open portion 171 as shown in the "A" region neighboring There is a fear that a short may be generated by being electrically connected to the unit back electrode 180.

The method for manufacturing a thin film solar cell according to another embodiment of the present invention described below relates to a method in which there is no fear of short circuit between unit cells.

4A to 4F are cross-sectional views illustrating a manufacturing method of a thin film solar cell according to another embodiment of the present invention. The same reference numerals are used to refer to the same elements as the above-described embodiments, and detailed description thereof will be omitted. .

First, as shown in FIG. 4A, the front electrode layer 120a is formed on the substrate 100.

Next, as shown in FIG. 4B, the front electrode layer 120a is patterned to form a plurality of unit front electrodes 120 spaced at predetermined intervals.

The patterning process of the front electrode layer 120a may be performed by irradiating a laser beam. Meanwhile, instead of forming the front electrode layer 120a on the entire surface of the substrate 100 and patterning the unit front electrode 120 using a laser scribing process as shown in FIGS. 4A and 4B, screen printing is performed. It is also possible to directly form the unit front electrode 120 on the substrate 100 using a simpler method such as inkjet printing, gravure printing or microcontact printing. Do.

Next, as shown in FIG. 4C, the semiconductor layer 140a is formed on the entire surface of the substrate 100.

As shown in FIG. 4D, a transparent conductive layer 160a is formed on the semiconductor layer 140a. The formation process of the transparent conductive layer 160a can be omitted.

Next, as shown in FIG. 4E, the semiconductor layer 140a and the transparent conductive layer 160a are simultaneously patterned, and the plurality of unit semiconductor layers spaced apart from each other with a predetermined contact portion 170 and a separation portion 172 therebetween. 140 and the unit transparent conductive layer 160 are formed.

The patterning process of the semiconductor layer 140a and the transparent conductive layer 160a may be performed using a laser scribing process.

In this case, the present invention is characterized by simultaneously forming the contact portion 170 and the separating portion 172 through one laser beam irradiation, which will be described below with reference to FIGS. 5 to 7.

5 is a schematic diagram of a laser scribing apparatus according to an embodiment of the present invention. As can be seen in FIG. 5, the laser scribing apparatus according to the present invention includes a laser oscillator 300 and a first mirror 410. ), A second mirror 430, a first lens 510, and a second lens 530. When the laser beam is emitted from the laser oscillator 300, the emitted laser beam is incident to the first mirror 410. In this case, the first mirror 410 passes a portion, preferably half, of the incident laser beam and reflects the rest of the incident laser beam. Accordingly, the laser beam passed through the first mirror 410 is irradiated to the object through the first lens 510, and the laser beam reflected from the first mirror 410 is the second mirror 430. Through the second lens 530 is irradiated to the object. In this case, the second mirror 430 reflects all of the incident laser beams.

As a result, since the laser beam emitted from the one laser oscillator 300 is irradiated into two parts, the contact part 170 and the separation part 172 may be simultaneously formed by the two laser beams. It becomes possible.

6 is a schematic diagram of a laser scribing apparatus according to another embodiment of the present invention. As can be seen in FIG. 6, the laser scribing apparatus according to the present invention includes a laser oscillator 300 and a first mirror 410. ), Second mirror 430, third mirror 413, fourth mirror 416, fifth mirror 433, sixth mirror 436, first lens 513, second lens 516 , A third lens 533, and a fourth lens 536.

Such a laser scribing apparatus according to FIG. 6 is designed so that the laser beam emitted from one laser oscillator 300 is finally divided into four and irradiated. In the laser scribing apparatus according to FIG. 5, since the laser beam emitted from one laser oscillator 300 is finally divided and irradiated into two, the contact unit 170 and the separation unit only for one unit cell in the process of FIG. 4E. 6 can be formed at the same time, the laser scribing apparatus according to FIG. 6 is divided into four laser beams emitted from two laser oscillators 300 and irradiated into four at the same time. The contact unit 170 and the separation unit 172 may be formed at the same time for the unit cell.

In the laser scribing apparatus according to FIG. 6, when the laser beam is emitted from the laser oscillator 300, the emitted laser beam is incident to the first mirror 410. In this case, the first mirror 410 passes a portion of the incident laser beam, preferably half of the incident laser beam, and reflects the remainder of the incident laser beam to the second mirror 430.

The third mirror 413 passes a portion, preferably half, of the incident laser beam and reflects the remainder of the incident laser beam. Accordingly, the laser beam passing through the third mirror 413 is irradiated to the object through the first lens 513, and the laser beam reflected from the third mirror 413 passes through the fourth mirror 416. The object is irradiated through the second lens 516. In this case, the fourth mirror 430 reflects all of the incident laser beams.

The second mirror 430 reflects all of the incident laser beams to the fifth mirror 433, and the fifth mirror 433 passes a portion, preferably half, of the incident laser beams, The rest of the laser beam is reflected. Accordingly, the laser beam passing through the fifth mirror 433 is irradiated to the object through the third lens 533, and the laser beam reflected from the fifth mirror 433 passes through the sixth mirror 436. The object is irradiated through the fourth lens 536. In this case, the sixth mirror 436 reflects all of the incident laser beams.

FIG. 7A is a schematic diagram of a laser scribing apparatus according to another embodiment of the present invention, and FIG. 7B illustrates a profile of a laser beam irradiated from the laser scribing apparatus according to FIG. 7A.

As can be seen in Figure 7a, the laser scribing equipment according to the present invention comprises a laser oscillator 300, a beam shaper (400), and a lens (500).

As shown in FIGS. 7A and 7B, when the laser beam is emitted from the laser oscillator 300, the emitted laser beam passes through the beam shaper 400 to change the profile of the beam and is irradiated from the lens 500. The laser beam will have two beam spots. Therefore, since the laser beam has two beam spots, the laser beam is divided into two as shown in FIG. 5, so that the contact part 170 and the separation part 172 can be simultaneously formed. .

Next, as shown in FIG. 4F, a plurality of unit back electrodes 180 connected to the unit front electrode 120 through the contact unit 170 and spaced apart from the separation unit 172 are formed.

Since the contact unit 170 and the separation unit 172 are spaced apart at predetermined intervals, there is no fear that the back electrode forming material flows into the separation unit 172 during the process of forming the rear electrode 180. There is no fear of short circuit between unit cells as in step 2f.

The unit back electrode 180 is performed by screen printing, inkjet printing, gravure printing, or microcontact printing.

<Thin-film solar cell>

FIG. 8 is a cross-sectional view of a thin film solar cell according to an embodiment of the present invention, and FIG. 9 is a cross-sectional view of a thin film solar cell according to another embodiment of the present invention, each of the method and FIG. 2A to 2F described above. It relates to a thin-film solar cell manufactured by the method according to 4a to 4f. Therefore, description of overlapping portions will be omitted.

As can be seen in Figure 8, the thin-film solar cell according to an embodiment of the present invention is a substrate 100, a unit front electrode 120, a unit semiconductor layer 140, a unit transparent conductive layer 160, and a unit back electrode ( 180).

The unit front electrodes 120 are formed on the substrate 100 at a plurality of spaced apart from each other at predetermined intervals. The surface of the unit front electrode 120 may be formed in an uneven structure.

The plurality of unit semiconductor layers 140 are formed to be spaced apart from each other with an open part for connecting between electrodes and separating between unit cells. The unit semiconductor layer 140 is formed on the space between the unit front electrodes 120 and on the unit front electrode 120. In addition, the unit semiconductor layer 140 has a PIN structure.

The unit transparent conductive layer 160 is formed on the unit semiconductor layer 140 in the same pattern as the unit semiconductor layer 140. That is, a plurality of unit transparent conductive layers 160 are also formed to be spaced apart from each other with an open part for inter-electrode connection and separation between unit cells. However, the unit transparent conductive layer 160 may be omitted.

The unit back electrode 180 is connected to the unit front electrode 120 through the open part. In this case, the unit back electrode 180 is formed only on a part of the open part, and the remaining part of the open part in which the unit back electrode 180 is not formed serves as a separator 172 for separating between unit cells. Thus, a plurality of unit back electrodes 180 are formed to be spaced apart from each other with the separator 172 therebetween. Only the unit back electrode 180 and the separation unit 172 are formed in the open portion above the unit front electrode 120, and the unit semiconductor layer 140 or the unit transparent conductive layer 160 is not formed.

As can be seen in Figure 9, a thin film solar cell according to another embodiment of the present invention is a substrate 100, a unit front electrode 120, a unit semiconductor layer 140, a unit transparent conductive layer 160, and a unit back electrode ( 180).

The unit front electrodes 120 are formed on the substrate 100 at a plurality of spaced apart from each other at predetermined intervals.

The plurality of unit semiconductor layers 140 are formed to be spaced apart from each other with a contact unit 170 for connecting between electrodes and a separation unit 172 for separating between unit cells.

The unit transparent conductive layer 160 is formed on the unit semiconductor layer 140 in the same pattern as the unit semiconductor layer 140. That is, the unit transparent conductive layer 160 is also formed in a plurality of spaced apart with a contact portion 170 for inter-electrode connection and the separation unit 172 for separation between unit cells. However, the unit transparent conductive layer 160 may be omitted.

The unit back electrode 180 is connected to the unit front electrode 120 through the contact unit 170, and a plurality of unit back electrodes 180 are spaced apart from each other with the separation unit 172 therebetween.

1A to 1F are cross-sectional views illustrating a conventional manufacturing process of a thin film solar cell having a plurality of unit cells connected in series.

2A to 2F are cross-sectional views illustrating a manufacturing process of a thin film solar cell according to an embodiment of the present invention.

3 is a cross-sectional view illustrating a problem in which short between unit rear electrodes occurs in a thin film solar cell.

4A to 4F are cross-sectional views illustrating a thin film solar cell manufacturing process according to another exemplary embodiment of the present invention.

5 is a schematic diagram of a laser scribing apparatus according to an embodiment of the present invention.

6 is a schematic diagram of a laser scribing apparatus according to another embodiment of the present invention.

FIG. 7A is a schematic diagram of a laser scribing apparatus according to another embodiment of the present invention, and FIG. 7B illustrates a profile of a laser beam irradiated from the laser scribing apparatus according to FIG. 7A.

8 is a cross-sectional view of a thin film solar cell according to an embodiment of the present invention.

9 is a cross-sectional view of a thin film solar cell according to another embodiment of the present invention.

DESCRIPTION OF THE REFERENCE NUMERALS OF THE DRAWINGS FIG.

100: substrate 120: unit front electrode

140: unit semiconductor layer 160: unit transparent conductive layer

171: open portion 170: contact portion

172: separator 180: unit back electrode

Claims (15)

Forming a plurality of unit front electrodes spaced at predetermined intervals on the substrate; Forming a plurality of unit semiconductor layers spaced apart from each other via the open portions constituting the contact portion and the separation portion on the unit front electrode; And And forming a plurality of unit back electrodes spaced apart from each other with the separation unit interposed therebetween through the contact unit. The method of claim 1, wherein the contact portion and the separation portion contact each other. Forming a plurality of unit front electrodes spaced at predetermined intervals on the substrate; Forming a semiconductor layer on the entire surface of the substrate; Forming a plurality of unit semiconductor layers spaced apart from each other by interposing a predetermined contact portion and a separation portion in the semiconductor layer; And And a step of forming a plurality of unit back electrodes connected to the unit front electrode through the contact unit and spaced apart by the separation unit. The method of claim 1, wherein the contact portion and the separation portion are simultaneously formed through a single irradiation process of a laser beam. delete 3. The method of claim 2, In the step of irradiating the laser beam, the thin film type solar cell is characterized by simultaneously forming the contact portion and the separating portion by one laser beam irradiation by dividing and irradiating a laser beam emitted from one laser oscillator into a plurality of laser beams. Method for producing a battery. 5. The method of claim 4, The process of irradiating the laser beam is performed using a predetermined laser scribing equipment, and the laser scribing equipment is Laser oscillator; A first mirror to which a laser beam emitted from the laser oscillator is incident, which passes a portion of the incident laser beam and reflects the remainder of the incident laser beam; A second mirror reflecting all of the laser beams reflected from the first mirror; A first lens to which the laser beam passing through the first mirror is incident; And And a second lens through which the laser beam reflected from the second mirror is incident. 5. The method of claim 4, The process of irradiating the laser beam is performed using a predetermined laser scribing equipment, and the laser scribing equipment is Laser oscillator; A first mirror to which a laser beam emitted from the laser oscillator is incident, which passes a portion of the incident laser beam and reflects the remainder of the incident laser beam; A second mirror reflecting all of the laser beams reflected from the first mirror; A third mirror passing through a portion of the laser beam passing through the first mirror and reflecting a portion of the laser beam passing through the first mirror; A fourth mirror reflecting all of the laser beams reflected from the third mirror; A fifth mirror passing through a portion of the laser beam reflected from the second mirror and reflecting a portion of the laser beam reflected from the second mirror; A sixth mirror reflecting all of the laser beam reflected from the fifth head; A first lens into which the laser beam passing through the third mirror is incident; A second lens into which the laser beam reflected from the fourth mirror is incident; A third lens into which the laser beam passing through the fifth mirror is incident; And And a fourth lens into which the laser beam reflected from the sixth mirror is incident. 3. The method of claim 2, The step of irradiating the laser beam comprises changing the profile of the laser beam emitted from one laser oscillator and irradiating a laser beam having a plurality of beam spots to simultaneously form the contact portion and the disconnection portion by one laser beam irradiation. Method of manufacturing a thin-film solar cell, characterized in that. 8. The method of claim 7, The process of irradiating the laser beam is performed using a predetermined laser scribing equipment, and the laser scribing equipment includes a laser oscillator, a beam shaper, and a lens. . The method according to claim 1 or 2, The process of forming the unit front electrode And forming a front electrode layer on the substrate and irradiating a laser beam to the front electrode layer to pattern the front electrode layer. The method according to claim 1 or 2, The method of forming the unit front electrode is a method of manufacturing a thin film solar cell, characterized in that performed using a screen printing method, an inkjet printing method, a gravure printing method or a microcontact printing method. The method according to claim 1 or 2, The method of forming the unit back electrode may be performed by using a screen printing method, an inkjet printing method, a gravure printing method, or a microcontact printing method. The method according to claim 1 or 2, The method of manufacturing a thin film solar cell further comprising the step of forming a unit transparent conductive layer having the same pattern as the unit semiconductor layer on the unit semiconductor layer. delete delete delete

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