Anti-reflection heterojunction solar cell, preparation method thereof and electric equipment

Abstract

The invention discloses an antireflection heterojunction solar cell, a preparation method thereof and electric equipment. The solar cell comprises a silicon wafer substrate, a passivation layer, a back electrode, an emission layer, a transparent conductive film layer, an anti-reflection layer and a front electrode, and the passivation layer and the back electrode are sequentially deposited on the back surface of the silicon wafer substrate. The emission layer, the transparent conductive thin film layer, the anti-reflection layer and the front electrode are sequentially deposited on the front surface of the silicon wafer substrate, the anti-reflection layer comprises at least one composite layer composed of a carbon-doped TiO2 layer and a SiO2 layer, a carbon-doped TiO2 / SiO2 laminated anti-reflection film is adopted, and the reflection loss of the surface of the cell is reduced through the design of the gradient refractive index; when the TiO2 layer is prepared, the optical performance of the TiO2 layer is optimized by using a carbon-doped process, and the photoelectric conversion efficiency of the cell is improved.

Description

Technical Field

[0001] The invention relates to the technical field of solar cells, and in particular to an anti-reflection heterojunction solar cell and a preparation method and electrical equipment thereof. Background Art

[0002] At present, the surface of crystalline silicon heterojunction solar cells is generally textured to form a velvet surface to reduce light reflection on the cell surface. The textured silicon wafer substrate has a relatively high defect state density, which is easy to form carrier recombination centers; and the velvet surface will have an adverse effect on the quality of the silicon film subsequently deposited thereon, making it difficult to obtain a high-quality silicon film layer and a good crystalline silicon interface, and passivation is difficult, which affects the open circuit voltage of the heterojunction cell and hinders the further improvement of the cell efficiency. Summary of the invention

[0003] The present invention aims to solve one of the technical problems in the related art at least to a certain extent.

[0004] To this end, an embodiment of the present invention provides an anti-reflection heterojunction solar cell and a preparation method and electrical equipment thereof.

[0005] In the first aspect, the present invention proposes an anti-reflection heterojunction solar cell, comprising a silicon wafer substrate, a passivation layer, a back electrode, an emission layer, a transparent conductive film layer, an anti-reflection layer and a front electrode, wherein the passivation layer and the back electrode are deposited in sequence on the back surface of the silicon wafer substrate, the emission layer, the transparent conductive film layer, the anti-reflection layer and the front electrode are deposited in sequence on the front surface of the silicon wafer substrate, and the anti-reflection layer comprises a composite layer consisting of at least one carbon-doped TiO2 layer and a SiO2 layer.

[0006] Furthermore, the silicon wafer substrate is n-type or p-type single crystal silicon or polycrystalline silicon.

[0007] Furthermore, the thickness of the passivation layer is 10 to 60 nm, and the passivation layer is selected from SiO2, SiN x At least one of .

[0008] Furthermore, the emission layer is a single-layer or multi-layer silicon thin film.

[0009] Furthermore, the thickness of the anti-reflection layer is 50-100 nm.

[0010] Furthermore, the transparent conductive film layer is a metal oxide with a thickness of 40 to 80 nm.

[0011] In a second aspect, the present invention provides a method for preparing the anti-reflection heterojunction solar cell provided in the first aspect, such as Figure 1 As shown, the following steps are included:

[0012] (1) cleaning the silicon wafer substrate, depositing a passivation layer on the back surface thereof by using a PECVD method, and depositing a back electrode on the surface of the passivation layer by using a magnetron sputtering method;

[0013] (2) depositing an emission layer on the front surface of the silicon wafer substrate by a PECVD method, and depositing a transparent conductive film layer on the emission layer by a magnetron sputtering method;

[0014] (3) depositing an anti-reflection layer on the surface of the transparent conductive film layer;

[0015] (4) A front electrode is screen-printed on the anti-reflection layer and sintered.

[0016] Furthermore, the step (3) comprises:

[0017] (a) using CH4, H2O, and TiCl4 as raw materials, using nitrogen and argon as purge gas and carrier gas respectively, and depositing a carbon-doped TiO2 layer on the surface of the transparent conductive film layer by an ALD method;

[0018] (b) using SiH4 and H2O as raw materials, a SiO2 layer is deposited on the surface of the carbon-doped TiO2 layer by a PECVD method.

[0019] Furthermore, the growth cycle parameters of the carbon-doped TiO2 layer in step (a) are: TiCl4 injection for 2 to 10 s, nitrogen purge for 15 to 35 s, H2O injection for 5 to 15 s, nitrogen purge for 10 to 20 s, CH4 injection for 10 to 30 s, nitrogen purge for 5 to 15 s; CH4 flow rate is 90 to 100 sccm, nitrogen flow rate is 150 to 200 sccm; growth temperature is 200 to 220°C, and the pressure in the reaction chamber is 3 to 8 mbar.

[0020] In a third aspect, the present invention proposes an electrical device comprising the anti-reflection heterojunction solar cell proposed in the first aspect or the anti-reflection heterojunction solar cell prepared by the method proposed in the second aspect.

[0021] Compared with the prior art, the beneficial effects of the present invention are:

[0022] The present invention adopts a carbon-doped TiO2 / SiO2 laminated anti-reflection film, and the gradient refractive index design reduces the reflection loss on the battery surface; the carbon-doping process is used when preparing the TiO2 layer to optimize its optical performance and improve the photoelectric conversion efficiency of the battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which:

[0024] Figure 1The present invention is a flow chart of the method for preparing the anti-reflective heterojunction solar cell. DETAILED DESCRIPTION

[0025] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.

[0026] Example 1

[0027] A method for preparing an anti-reflective heterojunction solar cell comprises the following steps:

[0028] (1) A p-type single crystal silicon wafer is selected as a silicon wafer substrate and cleaned with an HF solution, wherein the thickness of the silicon wafer substrate is 180 μm and the resistivity is 7 Ω.cm;

[0029] (2) using the PECVD method to deposit a 25 nm thick silicon nitride passivation layer on the back surface of the silicon wafer substrate;

[0030] (3) depositing a metal aluminum film as a back electrode on the surface of the passivation layer by a magnetron sputtering method;

[0031] (4) using the PECVD method to deposit a 20 nm thick n-type amorphous silicon layer on the front surface of the silicon wafer substrate as an emission layer;

[0032] (5) depositing a 50 nm thick ITO transparent conductive film layer on the emission layer by a magnetron sputtering method;

[0033] (6) A 30 nm thick carbon-doped TiO2 layer was deposited on the surface of the ITO transparent conductive layer on the front side of the silicon wafer by ALD method using CH4, H2O and TiCl4 as raw materials, nitrogen and argon as purge gas and carrier gas respectively; the growth cycle parameters of the carbon-doped TiO2 layer were: TiCl4 injection for 5 s, nitrogen purge for 15 s, H2O injection for 10 s, nitrogen purge for 15 s, CH4 injection for 10 s, nitrogen purge for 5 s; CH4 flow rate was 90 sccm, nitrogen flow rate was 150 sccm; the growth temperature was 200°C, and the pressure in the reaction chamber was 5 mbar;

[0034] (7) using SiH4 and H2O as raw materials, depositing a SiO2 layer with a thickness of 50 nm on the surface of the carbon-doped TiO2 layer by a PECVD method;

[0035] (8) A front electrode is screen-printed on the anti-reflection layer, and the front electrode is sintered on the conductive film layer.

[0036] Example 2

[0037] A method for preparing an anti-reflective heterojunction solar cell comprises the following steps:

[0038] (1) A p-type single crystal silicon wafer is selected as a silicon wafer substrate and cleaned with an HF solution, wherein the thickness of the silicon wafer substrate is 180 μm and the resistivity is 7 Ω.cm;

[0039] (2) using the PECVD method to deposit a 40 nm thick silicon nitride passivation layer on the back surface of the silicon wafer substrate;

[0040] (3) depositing a metal aluminum film as a back electrode on the surface of the passivation layer by a magnetron sputtering method;

[0041] (4) using the PECVD method to deposit a 20 nm thick n-type amorphous silicon layer on the front surface of the silicon wafer substrate as an emission layer;

[0042] (5) depositing a 40 nm thick ITO transparent conductive film layer on the emission layer by a magnetron sputtering method;

[0043] (6) A 30 nm thick carbon-doped TiO2 layer was deposited on the surface of the ITO transparent conductive layer on the front side of the silicon wafer by ALD method using CH4, H2O and TiCl4 as raw materials, nitrogen and argon as purge gas and carrier gas respectively; the growth cycle parameters of the carbon-doped TiO2 layer were: TiCl4 injection for 5 s, nitrogen purge for 15 s, H2O injection for 10 s, nitrogen purge for 15 s, CH4 injection for 10 s, nitrogen purge for 5 s; CH4 flow rate was 90 sccm, nitrogen flow rate was 150 sccm; the growth temperature was 200°C, and the pressure in the reaction chamber was 5 mbar;

[0044] (7) using SiH4 and H2O as raw materials, depositing a SiO2 layer with a thickness of 30 nm on the surface of the carbon-doped TiO2 layer by a PECVD method;

[0045] (8) A front electrode is screen-printed on the anti-reflection layer, and the front electrode is sintered on the conductive film layer.

[0046] Example 3

[0047] A method for preparing an anti-reflective heterojunction solar cell comprises the following steps:

[0048] (1) A p-type single crystal silicon wafer is selected as a silicon wafer substrate and cleaned with an HF solution, wherein the thickness of the silicon wafer substrate is 180 μm and the resistivity is 7 Ω.cm;

[0049] (2) using the PECVD method to deposit a 60 nm thick silicon nitride passivation layer on the back surface of the silicon wafer substrate;

[0050] (3) depositing a metal aluminum film as a back electrode on the surface of the passivation layer by a magnetron sputtering method;

[0051] (4) using the PECVD method to deposit a 20 nm thick n-type amorphous silicon layer on the front surface of the silicon wafer substrate as an emission layer;

[0052] (5) depositing an 80 nm thick ITO transparent conductive film layer on the emission layer by a magnetron sputtering method;

[0053] (6) A 30 nm thick carbon-doped TiO2 layer was deposited on the surface of the ITO transparent conductive layer on the front side of the silicon wafer by ALD method using CH4, H2O and TiCl4 as raw materials, nitrogen and argon as purge gas and carrier gas respectively; the growth cycle parameters of the carbon-doped TiO2 layer were: TiCl4 injection for 5 s, nitrogen purge for 15 s, H2O injection for 10 s, nitrogen purge for 15 s, CH4 injection for 10 s, nitrogen purge for 5 s; CH4 flow rate was 90 sccm, nitrogen flow rate was 150 sccm; the growth temperature was 200°C, and the pressure in the reaction chamber was 5 mbar;

[0054] (7) using SiH4 and H2O as raw materials, depositing a SiO2 layer with a thickness of 40 nm on the surface of the carbon-doped TiO2 layer by a PECVD method;

[0055] (8) A front electrode is screen-printed on the anti-reflection layer, and the front electrode is sintered on the conductive film layer.

[0056] Example 4

[0057] A method for preparing an anti-reflective heterojunction solar cell comprises the following steps:

[0058] (1) A p-type single crystal silicon wafer is selected as a silicon wafer substrate and cleaned with an HF solution, wherein the thickness of the silicon wafer substrate is 180 μm and the resistivity is 7 Ω.cm;

[0059] (2) using the PECVD method to deposit a 30 nm thick silicon nitride passivation layer on the back surface of the silicon wafer substrate;

[0060] (3) depositing a metal aluminum film as a back electrode on the surface of the passivation layer by a magnetron sputtering method;

[0061] (4) using the PECVD method to deposit a 20 nm thick n-type amorphous silicon layer on the front surface of the silicon wafer substrate as an emission layer;

[0062] (5) depositing a 60 nm thick ITO transparent conductive film layer on the emission layer by a magnetron sputtering method;

[0063] (6) A 50 nm thick carbon-doped TiO2 layer was deposited on the surface of the ITO transparent conductive layer on the front side of the silicon wafer by ALD method using CH4, H2O and TiCl4 as raw materials, nitrogen and argon as purge gas and carrier gas respectively; the growth cycle parameters of the carbon-doped TiO2 layer were: TiCl4 injection for 8 s, nitrogen purge for 20 s, H2O injection for 15 s, nitrogen purge for 20 s, CH4 injection for 15 s, nitrogen purge for 10 s; CH4 flow rate was 100 sccm, nitrogen flow rate was 200 sccm; the growth temperature was 220°C, and the pressure in the reaction chamber was 7 mbar;

[0064] (7) using SiH4 and H2O as raw materials, depositing a SiO2 layer with a thickness of 40 nm on the surface of the carbon-doped TiO2 layer by a PECVD method;

[0065] (8) A front electrode is screen-printed on the anti-reflection layer, and the front electrode is sintered on the conductive film layer.

[0066] Comparative Example 1

[0067] A method for preparing an anti-reflective heterojunction solar cell comprises the following steps:

[0068] (1) A p-type single crystal silicon wafer is selected as a silicon wafer substrate and cleaned with an HF solution, wherein the thickness of the silicon wafer substrate is 180 μm and the resistivity is 7 Ω.cm;

[0069] (2) using the PECVD method to deposit a 25 nm thick silicon nitride passivation layer on the back surface of the silicon wafer substrate;

[0070] (3) depositing a metal aluminum film as a back electrode on the surface of the passivation layer by a magnetron sputtering method;

[0071] (4) using the PECVD method to deposit a 20 nm thick n-type amorphous silicon layer on the front surface of the silicon wafer substrate as an emission layer;

[0072] (5) depositing a 50 nm thick ITO transparent conductive film layer on the emission layer by a magnetron sputtering method;

[0073] (6) A front electrode is screen-printed on the ITO transparent conductive film layer, and the front electrode is sintered on the conductive film layer.

[0074] Comparative Example 2

[0075] A method for preparing an anti-reflective heterojunction solar cell comprises the following steps:

[0076] (1) A p-type single crystal silicon wafer is selected as a silicon wafer substrate and cleaned with an HF solution, wherein the thickness of the silicon wafer substrate is 180 μm and the resistivity is 7 Ω.cm;

[0077] (2) using the PECVD method to deposit a 25 nm thick silicon nitride passivation layer on the back surface of the silicon wafer substrate;

[0078] (3) depositing a metal aluminum film as a back electrode on the surface of the passivation layer by a magnetron sputtering method;

[0079] (4) using the PECVD method to deposit a 20 nm thick n-type amorphous silicon layer on the front surface of the silicon wafer substrate as an emission layer;

[0080] (5) depositing a 50 nm thick ITO transparent conductive film layer on the emission layer by a magnetron sputtering method;

[0081] (6) Using SiH4 and H2O as raw materials, a SiO2 layer with a thickness of 50 nm was deposited on the surface of ITO by PECVD method;

[0082] (7) A front electrode is screen-printed on the anti-reflection layer, and the front electrode is sintered on the conductive film layer.

[0083] Comparative Example 3

[0084] A method for preparing an anti-reflective heterojunction solar cell comprises the following steps:

[0085] (1) A p-type single crystal silicon wafer is selected as a silicon wafer substrate and cleaned with an HF solution, wherein the thickness of the silicon wafer substrate is 180 μm and the resistivity is 7 Ω.cm;

[0086] (2) using the PECVD method to deposit a 25 nm thick silicon nitride passivation layer on the back surface of the silicon wafer substrate;

[0087] (3) depositing a metal aluminum film as a back electrode on the surface of the passivation layer by a magnetron sputtering method;

[0088] (4) using the PECVD method to deposit a 20 nm thick n-type amorphous silicon layer on the front surface of the silicon wafer substrate as an emission layer;

[0089] (5) depositing a 50 nm thick ITO transparent conductive film layer on the emission layer by a magnetron sputtering method;

[0090] (6) A 30 nm thick carbon-doped TiO2 layer was deposited on the surface of the ITO transparent conductive layer on the front side of the silicon wafer by ALD method using CH4, H2O and TiCl4 as raw materials, nitrogen and argon as purge gas and carrier gas respectively; the growth cycle parameters of the carbon-doped TiO2 layer were: TiCl4 injection for 5 s, nitrogen purge for 15 s, H2O injection for 10 s, nitrogen purge for 15 s, CH4 injection for 10 s, nitrogen purge for 5 s; CH4 flow rate was 90 sccm, nitrogen flow rate was 150 sccm; the growth temperature was 200°C, and the pressure in the reaction chamber was 5 mbar;

[0091] (7) A front electrode is screen-printed on the anti-reflection layer, and the front electrode is sintered on the conductive film layer.

[0092] Comparative Example 4

[0093] A method for preparing an anti-reflective heterojunction solar cell comprises the following steps:

[0094] (1) A p-type single crystal silicon wafer is selected as a silicon wafer substrate and cleaned with an HF solution, wherein the thickness of the silicon wafer substrate is 180 μm and the resistivity is 7 Ω.cm;

[0095] (2) using the PECVD method to deposit a 25 nm thick silicon nitride passivation layer on the back surface of the silicon wafer substrate;

[0096] (3) depositing a metal aluminum film as a back electrode on the surface of the passivation layer by a magnetron sputtering method;

[0097] (4) using the PECVD method to deposit a 20 nm thick n-type amorphous silicon layer on the front surface of the silicon wafer substrate as an emission layer;

[0098] (5) depositing a 50 nm thick ITO transparent conductive film layer on the emission layer by a magnetron sputtering method;

[0099] (6) A 30 nm thick carbon TiO2 layer was deposited on the surface of the ITO transparent conductive layer on the front side of the silicon wafer by ALD method, using H2O and TiCl4 as raw materials, nitrogen and argon as purge gas and carrier gas respectively; the growth cycle parameters of the TiO2 layer were: TiCl4 injection for 5 s, nitrogen purge for 15 s, H2O injection for 10 s, nitrogen purge for 15 s; the nitrogen flow rate was 150 sccm, the growth temperature was 200°C, and the pressure in the reaction chamber was 5 mbar;

[0100] (7) using SiH4 and H2O as raw materials, depositing a SiO2 layer with a thickness of 50 nm on the surface of the carbon-doped TiO2 layer by a PECVD method;

[0101] (8) A front electrode is screen-printed on the anti-reflection layer, and the front electrode is sintered on the conductive film layer.

[0102] Test Example 1

[0103] The heterojunction solar cells prepared in Examples 1 to 4, i.e. Comparative Examples 1 to 4, were subjected to performance tests, and the test results are shown in Table 1 below.

[0104] Table 1:

[0105]

[0106]

[0107] As can be seen from Table 1, the heterojunction solar cells prepared in Examples 1 to 4 have relatively high photoelectric conversion efficiency, open circuit voltage, short circuit current and fill factor. In Comparative Example 1, no anti-reflection layer is provided, and the photoelectric conversion efficiency of the cell is significantly reduced compared with that in Example 1. In Comparative Example 2, only a SiO2 anti-reflection layer is provided, and in Comparative Example 3, only a carbon-doped TiO2 anti-reflection layer is provided. Compared with Example 1, the cell performance of Comparative Example 2 and Comparative Example 3 is reduced. In Comparative Example 4, TiO2 is not carbon-doped. Compared with Comparative Example 1, the cell performance of Comparative Example 4 is reduced, which shows that carbon doping can optimize the optical properties of solar cells.

[0108] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms may be for different embodiments or examples. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, unless they are contradictory.

[0109] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0110] Although the embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. An anti-reflective heterojunction solar cell, characterized in that: It includes a silicon wafer substrate, a passivation layer, a back electrode, an emission layer, a transparent conductive film layer, an anti-reflection layer and a front electrode, wherein the passivation layer and the back electrode are deposited in sequence on the back surface of the silicon wafer substrate, the emission layer, the transparent conductive film layer, the anti-reflection layer and the front electrode are deposited in sequence on the front surface of the silicon wafer substrate, and the anti-reflection layer includes a composite layer consisting of at least one carbon-doped TiO2 layer and a SiO2 layer.

2. The solar cell according to claim 1, wherein: The silicon wafer substrate is n-type or p-type single crystal silicon or polycrystalline silicon.

3. The solar cell according to claim 1, wherein: The thickness of the passivation layer is 10 to 60 nm, and the passivation layer is selected from SiO2, SiN x At least one of .

4. The solar cell according to claim 1, wherein: The emission layer is a single-layer or multi-layer silicon thin film.

5. The solar cell according to claim 1, wherein: The thickness of the anti-reflection layer is 30-100 nm.

6. The solar cell according to claim 1, wherein: The transparent conductive film layer is a metal oxide with a thickness of 40 to 80 nm.

7. A method for preparing an anti-reflective heterojunction solar cell, characterized in that: The method for preparing the solar cell according to any one of claims 1 to 6 comprises the following steps: (1) cleaning the silicon wafer substrate, depositing a passivation layer on the back surface thereof by using a PECVD method, and depositing a back electrode on the surface of the passivation layer by using a magnetron sputtering method; (2) depositing an emission layer on the front surface of the silicon wafer substrate by a PECVD method, and depositing a transparent conductive film layer on the emission layer by a magnetron sputtering method; (3) depositing an anti-reflection layer on the surface of the transparent conductive film layer; (4) A front electrode is screen-printed on the anti-reflection layer and sintered.

8. The method according to claim 7, characterized in that The step (3) comprises: (a) using CH4, H2O, and TiCl4 as raw materials, using nitrogen and argon as purge gas and carrier gas respectively, and depositing a carbon-doped TiO2 layer on the surface of the transparent conductive film layer by an ALD method; (b) using SiH4 and H2O as raw materials, a SiO2 layer is deposited on the surface of the carbon-doped TiO2 layer by a PECVD method.

9. The method according to claim 8, characterized in that The growth cycle parameters of the carbon-doped TiO2 layer in the step (a) are: TiCl4 injection for 2 to 10 s, nitrogen purge for 15 to 35 s, H2O injection for 5 to 15 s, nitrogen purge for 10 to 20 s, CH4 injection for 10 to 30 s, nitrogen purge for 5 to 15 s; CH4 flow rate is 90 to 100 sccm, nitrogen flow rate is 150 to 200 sccm; growth temperature is 200 to 220°C, and the pressure in the reaction chamber is 3 to 8 mbar.

10. An electrical device, characterized in that: The invention comprises the solar cell according to claims 1 to 6 or the solar cell prepared by the method according to claims 7 to 9.

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