CN103779430A - Conductive antireflection film of crystalline silicon solar cell and crystalline silicon solar cell - Google Patents

Abstract

The invention provides a conductive anti-reflection film for a crystalline silicon solar cell, the conductive anti-reflection film has a double-functional layer structure, the functional layer close to the silicon substrate of the crystalline silicon solar cell is a passivation layer, and is far away from the silicon lining of the crystalline silicon solar cell The bottom functional layer is a conductive layer; the conductive medium used in the conductive layer is selected from at least one of AZO, ITO, ATO, and SnO ₂ . The invention also provides a crystalline silicon solar cell using the conductive anti-reflection film. The conductive anti-reflection film provided by the invention can passivate the silicon surface well, and can also effectively collect the photogenerated carriers generated by the PN junction, so that their recombination is suppressed, and the light utilization rate is large; at the same time, the conductive layer can also direct the battery to the light. The grid lines of the surface electrodes are effectively connected, so that the electrode resistance is evenly distributed, the series resistance of the battery is reduced, the filling factor is significantly increased, and the photoelectric conversion efficiency of the battery is improved. In addition, the manufacturing process of the crystalline silicon solar cell provided by the invention is simple and suitable for large-scale commercial production.

Description

Conductive anti-reflection film for crystalline silicon solar cell and crystalline silicon solar cell

technical field

The invention relates to the field of solar cells, more specifically, the invention relates to a conductive anti-reflection film of a crystalline silicon solar cell and a crystalline silicon solar cell comprising the conductive anti-reflection film.

Background technique

As a kind of green energy, solar energy has attracted more and more attention due to its advantages of inexhaustibility, no pollution, and no limitation of geographical resources. In order to improve the photoelectric conversion efficiency of crystalline silicon solar cells, reduce the light reflection loss on the surface of the cell, and increase light transmission, the antireflection film in the solar cell structure plays a very important role.

At present, the process that has been industrialized on a large scale is to deposit a layer of silicon nitride film with a suitable thickness on the silicon wafer after diffusion by plasma chemical vapor deposition (PECVD). The silicon nitride film layer has anti-reflection effect while , also has a certain passivation effect. In the process of depositing silicon nitride film by PECVD, after the reaction gas ammonia gas and silane gas are ionized, the hydrogen ions in it combine with the dangling bonds on the silicon surface to form a surface passivation effect, which can effectively suppress the photogenerated carriers. Composite, improve the photoelectric conversion efficiency of the battery. However, the anti-reflectivity of a single-layer silicon nitride film is not very low, and there is still room for improvement.

Therefore, how to further increase the utilization rate of incident light and improve the photoelectric efficiency of the battery is a hot spot in battery research at present. CN201120218873 discloses a double-layer anti-reflection film for crystalline silicon solar cells, which is composed of a titanium dioxide film and a silicon nitride film passivation layer, and the silicon nitride film is located between the titanium dioxide film and the silicon wafer; the double-layer anti-reflection film can be Reduce the reflection of light on the surface of the battery, and the reflectance between 300 and 1200nm in the spectral range is reduced by about 10% compared with that without coating. In this method, the reflectivity of incident light is only reduced by using a double-layer structure reflective film, and the effect of reducing light reflection is very limited. The photoelectric conversion efficiency of the solar cell using the double-layer structure anti-reflection film is still low.

CN201859880U provides a solar cell with a conductive anti-reflection film, which includes a passivation layer on the upper surface of the solar cell body, a main electrode is evaporated on the surface of the passivation layer, and then a conductive electrode is evaporated around the main electrode. Anti-reflection coating; conductive anti-reflection coating consists of bottom layer (TiO ₂ ) and surface layer (SiO ₂ or Al ₂ O ₃ ). The battery is expected to replace the grid electrode on the light-facing side of the solar cell with a conductive anti-reflection film, that is, the conductive anti-reflection film is also used to collect current, thereby increasing the light-receiving area of the battery. However, since the conductive anti-reflection film is covered on the passivation layer, the passivation film is usually a non-conductor, so in fact the conductive anti-reflection film cannot collect photo-generated current at all. Moreover, the conductive effect of the conductive anti-reflection film composed of such oxides is not good.

Contents of the invention

The present invention aims at the technical problem that the anti-reflection film existing in the crystalline silicon solar cell has a limited reduction in the reflectivity of the incident light, resulting in a low photoelectric conversion efficiency of the cell, and provides a crystalline silicon solar cell with a new structure The conductive anti-reflection film and the crystalline silicon solar cell using the conductive anti-reflection film.

Specifically, the technical solution of the present invention is:

A conductive anti-reflection film for a crystalline silicon solar cell, the conductive anti-reflection film is a double-functional layer structure, wherein the functional layer close to the silicon substrate of the crystalline silicon solar cell is a passivation layer, and the functional layer far away from the silicon substrate of the crystalline silicon solar cell is a passivation layer. The functional layer is a conductive layer; the conductive medium used in the conductive layer is selected from AZO (aluminum-doped zinc oxide), ITO (tin-doped indium oxide), ATO (antimony-doped tin oxide) or SnO ₂ (tin dioxide ) at least one of the

A crystalline silicon solar cell comprising a silicon substrate, an anti-reflection layer located on the light-facing surface of the silicon substrate, and a light-facing surface located on the surface of the anti-reflection layer and in contact with the silicon substrate through the anti-reflection layer Electrodes; the anti-reflection layer is the conductive anti-reflection film provided by the present invention.

The conductive anti-reflection film of the crystalline silicon solar cell provided by the present invention has a double-functional layer structure, and both the conductive layer and the passivation layer have an anti-reflection effect on incident light. Passivation can also effectively collect the photo-generated carriers generated by the PN junction, inhibit the recombination of photo-generated carriers, and increase the light utilization rate; at the same time, the conductive layer can also effectively connect the battery to the thin grid line of the photo-surface electrode, so that The electrode resistance is evenly distributed, the series resistance of the crystalline silicon solar cell adopting the conductive anti-reflection film is reduced, and the filling factor is significantly increased, so that the photoelectric conversion efficiency of the cell is significantly improved. In addition, the manufacturing process of the crystalline silicon solar cell provided by the invention is simple, the additional cost is small, and it is suitable for large-scale commercial production. 

Description of drawings

Fig. 1 is a schematic structural diagram of a crystalline silicon solar cell provided by the present invention.

In the figure: 1—conductive layer, 2—passivation layer, 3—light-facing electrode, 4—silicon substrate, 5—back field, 6—back electrode. the

Detailed ways

The invention provides a conductive anti-reflection film for a crystalline silicon solar cell, the conductive anti-reflection film is a double-functional layer structure, wherein the functional layer close to the silicon substrate of the crystalline silicon solar cell is a passivation layer, and is far away from the crystalline silicon solar cell The functional layer of the silicon substrate is a conductive layer; the conductive medium used in the conductive layer is selected from at least one of AZO, ITO, ATO or SnO ₂ .

Although CN201120218873 discloses a double-layer anti-reflection film for crystalline silicon solar cells, its titanium dioxide layer and silicon nitride film layer are used to reduce the reflection of the incident light, that is, it only further reduces the reflection through the double-layer film, and does not affect each layer. The performance of the anti-reflection film is essentially improved; while the conductive film (SiO ₂ or Al ₂ O ₃ ) provided by CN201859880U is covered on the passivation layer (TiO ₂ ), the conductive film is not in contact with the silicon wafer, and the passivation film as a poor conductor. The battery of this invention has no thin grid lines. In fact, the simple main grid lines cannot effectively collect photo-generated carriers, so the efficiency of the battery is limited.

The conductive anti-reflection film of the crystalline silicon solar cell provided by the present invention has a double-functional layer structure, and the functional layer close to the silicon substrate (referred to as the bottom layer) is a passivation layer; the functional layer far away from the silicon substrate (referred to as the surface layer) ) is the conductive layer. Both the conductive layer and the passivation layer have an anti-reflection effect on incident light. On the one hand, the double-layer anti-reflection film can passivate the silicon surface well, reduce or inhibit the recombination of photogenerated carriers on the surface of the silicon wafer, and can also be more Effectively collect the photo-generated carriers generated by the PN junction and increase the probability of carrier collection, so the light utilization rate increases greatly; at the same time, the conductive layer (surface layer) in the anti-reflection film can also transfer the battery to the thin surface of the light electrode. The gate lines are effectively connected to collect the photo-generated current and gather it to the main grid, so that the electrode resistance is evenly distributed, the series resistance is reduced, and the filling factor is significantly increased, so that the photoelectric conversion efficiency of the battery is significantly improved.

In the solar cell using the conductive anti-reflection film, the surface layer (that is, the conductive layer) is used to receive light. The present invention selects the material of the conductive medium used in the surface layer through a large number of experiments, and finally finds that AZO (aluminum-doped zinc oxide), ITO (tin-doped indium oxide), ATO (antimony-doped tin oxide) or SnO When at least one of ₂ (tin dioxide) is used as a conductive medium, the conductive layer formed by this type of material has little reflection of incident light, and it has good conductivity.

In the present invention, the thickness of the conductive layer can be properly selected according to the type and thickness of the material of the bottom layer (i.e. the passivation layer). The reflectivity of the film to incident light is minimal. In addition, the conductive layer (surface layer) can also use two or more conductive media, such as using a combination of AZO and SnO ₂ as the conductive layer, that is, first prepare a layer of AZO, and then prepare a layer of SnO ₂ on the AZO, Generally speaking, the anti-reflection effect of the conductive layer formed by the combination of two conductive media is better than that of a single layer, but its preparation process is complicated and the cost will increase greatly. Therefore, it is preferable to use a single conductive media layer.

Therefore, in the present invention, preferably, the conductive layer can directly use single-layer AZO. The inventors found that the source of raw materials for forming the AZO conductive film layer is relatively abundant, it has less environmental pollution, the film has better electrical conductivity, and the optical performance of the passivation layer is well matched, and the preparation process of the film is simple and mature.

The thickness of the conductive layer in the conductive antireflection film of the present invention is 20 ~ 80nm, and its specific thickness can be determined according to the type of the conductive medium and the medium type and thickness of the passivation layer. The design principle is to minimize the light reflectance of the entire antireflection film , and the conductivity of the conductive layer is as large as possible.

The preparation method of the conductive layer may adopt magnetron sputtering method, pulsed laser deposition (PLD) method, sol-gel (Sol-Gel) method or chemical vapor deposition (CVD) method commonly used in the prior art. The magnetron sputtering method is preferred, because this method has high deposition rate, low substrate temperature, good film adhesion, low cost and easy control. The target material of magnetron sputtering is an alloy or pure oxide corresponding to the substance to be plated, and the specific process of forming a conductive oxide on the target material by magnetron sputtering is well known to thin film preparation personnel. For example, taking the deposition of AZO conductive layer as an example, the target material during magnetron sputtering can be a Zn-Al metal target, oxidized with oxygen, diluted with argon gas, and the sputtering pressure is controlled at 0.5~1.0Pa, and the flow rate of argon gas The temperature of the silicon substrate is 200-300°C, and the sputtering time can be determined according to the height of the AZO film deposited on the silicon wafer.

In the present invention, the passivation layer may be a passivation layer commonly used in the prior art. Preferably, in the present invention, the passivation medium used in the passivation layer is SiO ₂ or Si ₃ N ₄ . On the one hand, the passivation layer can have a good passivation effect on the surface of the silicon substrate, and at the same time, it can also have an anti-reflection effect on incident light.

Specifically, in the present invention, if the passivation layer uses SiO ₂ as the passivation medium, it can be formed by thermal oxidation or vacuum evaporation. The thermal oxidation method has simple process and low equipment cost, so thermal oxidation process is preferred. During the thermal oxidation process, a large number of oxygen atoms and unsaturated silicon atoms on the surface of the silicon substrate combine to form a layer of _SiO2 film, thereby reducing the density of dangling bonds, which can well control the interface traps and fixed charges, and reduce the surface state Density acts as a surface passivator. Specifically, the step of passivating the surface of the silicon substrate to form a passivation layer includes: putting the silicon wafer substrate after texturing, diffusion, etching, and dephosphorous silicon glass into an oxygen atmosphere for thermal oxidation, and simultaneously during the oxidation stage The protective gas nitrogen is introduced, and the oxidation temperature is set at 800~850°C. The oxidation time is determined according to the thickness of the SiO ₂ film to be obtained, and is generally controlled between 100~500s.

Since the passivation effect of SiO ₂ is generally better than that of silicon nitride, in the present invention, the passivation medium used for the passivation layer is preferably SiO ₂ . Moreover, the thermal oxidation of the silicon wafer substrate can be carried out on both sides, that is, there is no need to protect the backlight surface of the silicon wafer, and the silicon dioxide obtained on the backlight surface also has the effect of passivating the surface, which is also beneficial to suppress the photogenerated carriers on the back surface . Further, in the present invention, when the passivation medium used for the passivation layer is SiO ₂ , the thickness of the passivation layer is 5-20 nm. If the thickness of the passivation layer is too small, it will affect the passivation effect on the surface of the silicon wafer. If the thickness of the passivation layer is too large, it will increase the time for forming the passivation layer. High temperature will cause the impurities in the silicon wafer to redistribute and affect the quality of the silicon wafer. _{Both oc} and I _SC flow decreased.

The passivation medium employed in the passivation layer may also be silicon nitride. When silicon nitride is used as the passivation medium, the thickness of the corresponding passivation layer is between 15 and 60 nm. This is because the passivation effect of silicon nitride is weaker than that of SiO ₂ , and its deposition temperature is low, so its choice The thickness can be greater than SiO ₂ . The passivation mechanism of silicon nitride is well known to those skilled in the art and will not be repeated here. The preparation method for forming the silicon nitride passivation layer can be a chemical vapor deposition (PECVD) method, and its specific process is well known to those skilled in the art.

The present invention also provides a crystalline silicon solar cell using the conductive anti-reflection film, the structure of which is shown in Fig. The light-facing electrode 3 on the surface of the layer and in contact with the silicon substrate through the anti-reflection layer; the anti-reflection layer is the conductive anti-reflection film provided by the present invention, that is, it includes a conductive layer 1 and a passivation layer 2, wherein the conductive layer 1 away from the silicon substrate 4 , while the passivation layer 2 is close to the silicon substrate 4 .

As the common knowledge of those skilled in the art, the back side of the silicon substrate 4 is also provided with a back field 5 and a back electrode 6, and the back electrode 6 is in contact with the back side of the silicon substrate 4 through the back field 5, as shown in FIG. 1 .

After testing, the average photoelectric efficiency of the 156×156 polycrystalline solar cells prepared by using the conductive anti-reflection film provided by the invention is increased by more than 0.15%. In addition, the manufacturing process of the crystalline silicon solar cell provided by the invention is simple, the additional cost is small, and it is suitable for large-scale commercial production.

In order to make the technical problems, technical solutions and beneficial effects solved by the present invention clearer, the present invention will be further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described here are only used to explain the present invention, not to limit the present invention.

Example 1

(1) Put the 156×156 P-type polysilicon textured, diffused, etched, and dephosphorized silicon wafers into silicon wafers for double-sided thermal oxidation in an oxygen atmosphere. The temperature in the oxidation furnace is set at 820°C, and the oxidation time is is 312s, and the thickness of the obtained SiO ₂ passivation layer is 11.5±0.1nm (measured by a probe-type step meter produced by Ambious Technology Inc of the United States, the same below).

(2) Place the silicon wafer obtained in step (1) on the loading table of the DC magnetron sputtering machine, and then put it into the sputtering chamber to pre-fix Zn-Al in the chamber (the Al content is 3wt%) metal target for sputtering, close the sputtering chamber door, evacuate the chamber, set the sputtering pressure to 0.6Pa, the temperature of the silicon wafer substrate to 250°C, the flow rate of oxygen and argon (in terms of volume flow mL/min measurement, the same below) The ratio is 10:40, the sputtering power is 55W, and the sputtering time is 1920s, and the AZO conductive layer is obtained, and its thickness is 67.5±0.1nm. the

(3) Use 200-mesh screen printing silver conductive paste on the back of the silicon wafer obtained in step (2) (model is DuPont PV505, three-line eight-stage system, printing wet weight is 35~50 mg), and then use 280-mesh screen Print back field aluminum paste (model is Shuohe 108C, printing wet weight is 1.4~1.6g), drying, drying temperature is 150°C, drying time is 5 minutes, and then use 360 mesh, line width is 40μm The crystalline silicon solar cell of this embodiment obtained after sintering the front side silver paste with a wire diameter of 16 μm and a film thickness of 5 μm (the model is DuPont 17A, and the printed wet weight is 120-130 mg) is denoted as S1.

Example 2

The same steps as in Example 1 were used to prepare the crystalline silicon solar cell S2 of this example, except that:

In step (1), the temperature in the oxidation furnace is set to 850°C, the oxidation time is 480s, and the thickness of the obtained SiO ₂ passivation layer is 18.4±0.1nm;

In step (2), the sputtering time was 1680 s, and the thickness of the obtained AZO conductive layer was 61.3±0.1nm. the

Through the above steps, the crystalline silicon solar cell S2 of this embodiment is obtained.

Example 3

(1) Put the 156×156 P-type polysilicon textured, diffused, etched, and dephosphorized silicon wafers into a PECVD furnace for deposition. The vacuum pressure is 25 Pa, the deposition temperature is 440 ° C, ammonia and The flow ratio of silane gas is 2786:214, the power during deposition is 2900W, and the deposition time is 253s to obtain a silicon nitride passivation layer, and its thickness is 45±0.1nm. the

(2) A conductive layer was deposited on the surface of the passivation layer by the same steps as in step (2) of Example 1, except that the sputtering time was 1146s, and the thickness of the obtained AZO conductive layer was 40.7±0.1 nm. the

(3) The electrode paste and the back field paste were printed in the same steps as in step (3) of Example 1, dried and sintered to obtain the crystalline silicon solar cell of this example, denoted as S3.

Example 4

(1) A SiO ₂ passivation layer is formed on the surface of the silicon substrate by the same steps as in step (1) of Embodiment 1.

(2) Place the silicon wafer obtained in step (1) on the loading stage of the DC magnetron sputtering machine, and then put it into the sputtering chamber to pre-fix the In-Sn in the chamber (the Sn content is 5.0wt%) metal target for sputtering, close the sputtering chamber door, evacuate the chamber, set the sputtering pressure to 0.6Pa, the substrate temperature to 250°C, and the flow ratio of oxygen to argon to be 15:42 , the sputtering power was 75W, and the sputtering time was 2350s to obtain an ITO conductive layer, whose thickness was measured to be 72.4±0.1nm. the

(3) The electrode paste and the back field paste were printed by the same steps as in step (3) of Example 1, dried and sintered to obtain the crystalline silicon solar cell of this example, denoted as S4.

Example 5

(1) A SiO ₂ passivation layer is formed on the surface of the silicon substrate by the same steps as in step (1) of Embodiment 1.

(2) Place the silicon wafer obtained in step (1) on the loading stage of the DC magnetron sputtering machine, and then put it into the sputtering chamber to pre-fix the _SnO2 oxide target in the chamber for further processing. Sputtering, close the sputtering chamber door, vacuumize the chamber, set the sputtering pressure to 0.4Pa, the substrate temperature to 200°C, the sputtering power to 90W, and the sputtering time to 1850s to obtain the _SnO2 conductive layer, The thickness of the _SnO2 conductive layer was tested to be 52.5±0.1nm.

(3) The electrode paste and the back field paste were printed in the same steps as in step (3) of Example 1, dried and sintered to obtain the crystalline silicon solar cell of this example, denoted as S5.

Example 6

(1) A SiO ₂ passivation layer is formed on the surface of the silicon substrate by the same steps as in step (1) of Embodiment 1.

(2) Place the silicon wafer obtained in step (1) on the loading stage of the DC magnetron sputtering machine, and then put it into the sputtering chamber to pre-fix Zn-Al in the chamber (the Al content is 3wt%) metal target for sputtering, close the sputtering chamber door, evacuate the chamber, set the sputtering pressure to 0.6Pa, the temperature of the silicon wafer substrate to 250°C, the oxygen and argon gas flow rate (in terms of volumetric flow rate mL/min measurement, the same below) The ratio is 10:40, the sputtering power is 55W, and the sputtering time is 1100s to obtain an AZO conductive layer, and its thickness is 32.4±0.1nm. the

(3) Put the silicon wafer with AZO conductive layer obtained in step (2) back into the sputtering chamber to sputter with the _SnO2 oxide target fixed in the chamber in advance, close the door of the sputtering chamber, and The chamber is evacuated, the sputtering pressure is set to 0.4Pa, the substrate temperature is 200°C, the sputtering power is 65W, and the sputtering time is 950s to obtain a _SnO2 conductive layer covering the AZO layer, and test the thickness of the _SnO2 conductive layer It is 26.1±0.1nm.

The common thickness of the conductive functional layer with AZO and SnO ₂ double conductive media obtained in this embodiment is 58.5±0.2nm.

(4) The electrode paste and the back field paste were printed by the same steps as in step (3) of Example 1, dried and sintered to obtain the crystalline silicon solar cell of this example, denoted as S6.

Comparative example 1

(1) Put the 156×156 P-type polysilicon textured, diffused, etched, and dephosphorized silicon wafers into a PECVD furnace for deposition. The vacuum pressure is 25 Pa, the deposition temperature is 440 ° C, ammonia and The flow ratio of silane gas was 2786:214, the power during deposition was 2900W, and the deposition time was 450s to obtain a silicon nitride anti-reflection layer with a thickness of 76.8±0.1nm. the

(3) The electrode paste and the back field paste were printed by the same steps as in step (3) of Example 1, dried and sintered to obtain the crystalline silicon solar cell of this comparative example, denoted as DS1.

Comparative example 2

Using the steps disclosed in the specific implementation method in CN201120218873, a silicon nitride film with a thickness of 45nm and a titanium dioxide film with a thickness of 42nm were sequentially deposited on the surface of a 156×156 P-type polycrystalline silicon wafer, and then printed using the same steps as in step (3) of Example 1 The electrode paste and the back field paste were dried and sintered to obtain the crystalline silicon solar cell of this comparative example, denoted as DS2.

Comparative example 3

Place the 156×156 P-type polysilicon textured, diffused, etched, and phosphorus-silicate silicon wafers on the loading stage of the DC magnetron sputtering machine, and then put them into the sputtering chamber. The corresponding crucibles are filled with titanium dioxide and silicon dioxide respectively, close the vacuum chamber door and the air release valve, first draw a low vacuum, and then pump a high vacuum; select the crucible of titanium dioxide, turn on the scanning, gun filament, high voltage and beam current, and adjust the electron beam Adjust the position of the light spot to fully melt the titanium dioxide in the crucible, adjust the position of the light plate so that it falls on the center of the dry pass, adjust the electron beam current to make the titanium dioxide evaporate stably, open the oxygenation valve, open the baffle to evaporate the titanium dioxide; continue to charge the titanium dioxide after the evaporation of the titanium dioxide is completed Oxygen, choose the crucible of silicon dioxide, open the baffle and continue to evaporate, continue to oxygenate after the silicon dioxide is evaporated, finally close the oxygenation and open the gas valve to inflate the vacuum chamber, and obtain the silicon dioxide that has a passivation layer and a conductive anti-reflection film. After taking it out, print a main electrode on the surface of the conductive anti-reflection film, print the back field and the back electrode on the back, dry and sinter to obtain the crystalline silicon solar cell of this comparative example, which is denoted as DS3.

Performance Testing

Surface condition: Use a magnifying glass of 3 to 5 times to observe whether the color of the anti-reflection coating of the above-prepared crystalline silicon solar cells S1-S6 and DS1-DS3 is uniform, whether there is obvious color difference, and observe whether the surface is smooth, etc. If there is no obvious color difference and the surface is smooth, it is recorded as OK, otherwise it is recorded as NG.

Series resistance, fill factor and photoelectric conversion efficiency: The crystalline silicon solar cell samples S1-S6 and DS1-DS3 prepared above were tested with a single flash simulation test instrument. The test conditions are standard test conditions (STC): light intensity: 1000W/m ² ; spectrum: AM1.5; temperature: 25°C. The unit of series resistance is mΩ.

The test results are shown in Table 1. the

Table 1

。

.

From the comparison of the test results in Table 1 above, it can be seen that the volume resistance distribution of the light-facing electrode of the crystalline silicon solar cell prepared by using the conductive anti-reflection film provided by the present invention is uniform, the series resistance of the battery becomes smaller, and the fill factor increases significantly. , The photoelectric conversion efficiency of the cell has been improved; the production line experiment proves that the average photoelectric efficiency of the 156×156 polysilicon cell has increased by more than 0.15%.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present invention should be included in the protection of the present invention. within range.

Claims (12)

1. the conductive anti-reflecting film of a crystal-silicon solar cell, it is characterized in that, described conductive anti-reflecting film is bifunctional layer structure, is wherein passivation layer near the functional layer of crystal-silicon solar cell silicon substrate, is conductive layer away from the functional layer of crystal-silicon solar cell silicon substrate; The conducting medium that described conductive layer adopts is selected from AZO, ITO, ATO or SnO ₂in at least one.

2. conductive anti-reflecting film according to claim 1, is characterized in that, the conducting medium that described conductive layer adopts is AZO.

3. conductive anti-reflecting film according to claim 1, is characterized in that, described conductive layer is double-decker, and the conducting medium wherein adopting near one deck of passivation layer is AZO, and the conducting medium adopting away from one deck of passivation layer is SnO ₂.

4. conductive anti-reflecting film according to claim 1, is characterized in that, the thickness of described conductive layer is 20 ~ 80nm.

5. according to the conductive anti-reflecting film described in claim 1-3 any one, it is characterized in that, described conductive layer forms by magnetron sputtering method, pulsed laser deposition, sol-gel process or chemical vapour deposition technique preparation.

6. conductive anti-reflecting film according to claim 1, is characterized in that, the dielectric passivation that described passivation layer adopts is SiO ₂or Si ₃n ₄.

7. conductive anti-reflecting film according to claim 6, is characterized in that, the dielectric passivation that described passivation layer adopts is SiO ₂, the thickness of passivation layer is 5 ~ 20nm.

8. conductive anti-reflecting film according to claim 7, is characterized in that, described passivation layer forms by thermal oxidation or vacuum vapour deposition preparation.

9. conductive anti-reflecting film according to claim 6, is characterized in that, the dielectric passivation that described passivation layer adopts is Si ₃n ₄, the thickness of passivation layer is 15 ~ 60nm.

10. conductive anti-reflecting film according to claim 6, is characterized in that, described passivation layer is prepared formation by Plasma Enhanced Chemical Vapor Deposition (PECVD).

11. 1 kinds of crystal-silicon solar cells, is characterized in that, the phototropic face electrode that described crystal-silicon solar cell comprises silicon substrate, is positioned at the antireflection layer of silicon substrate phototropic face, is positioned at antireflection layer surface and contacts with silicon substrate through antireflection layer; Described antireflection layer is the conductive anti-reflecting film described in claim 1-10 any one.

12. crystal-silicon solar cells according to claim 11, is characterized in that, the described silicon substrate back side is also provided with back surface field and backplate, and backplate contacts with the silicon substrate back side through back surface field.

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