Heterojunction solar module

Abstract

The utility model discloses a heterojunction solar energy assembly comprising a glass panel assembly which can cover the front surface and / or the back surface of a photovoltaic cell assembly. The glass panel assembly comprises a glass layer and further comprises a first coating layer and a second coating layer, the first coating layer is arranged on the side, close to the photovoltaic cell assembly, of the glass layer, the second coating layer is arranged on the side, close to the photovoltaic cell assembly, of the first coating layer, and the refractive indexes of the glass layer, the first coating layer and the second coating layer are sequentially increased. The first coating layer and the second coating layer are sequentially arranged on the inner side of the glass layer with the low refractive index, a three-layer anti-reflection structure composed of the film layers with the high refractive index, the medium refractive index and the low refractive index is formed, incidence of ultraviolet rays is blocked, the incident light amount of visible light and infrared light is increased, the CTM of the heterojunction solar module can be improved, and the service life of the heterojunction solar module is prolonged. And the efficiency and the output power of the heterojunction solar module are improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to the field of solar energy utilization especially relates to a heterojunction solar module. BACKGROUND

[0002] In recent years, due to the continuous expansion of silicon wafer, cell and module production capacity, the cost of photovoltaic power generation has also shown a substantial decline. Therefore, reducing the proportion of integrated cost (BOS) in the overall photovoltaic power generation system cost structure becomes more important, which means that high-efficiency modules will play the most important role in reducing system cost, because they can save more BOS cost under the condition of providing the same power. Among all solar cell technologies, researching silicon-based heterojunction (HJT) solar cells has important significance because it has the advantages of high conversion efficiency (> 25%), simple structure, low process temperature (< 250 ℃), fewer process steps and low temperature coefficient.

[0003] Compared with traditional P-type monocrystalline / polycrystalline solar cells, HJT cells with N-type monocrystalline substrate have the characteristics of high efficiency, simple process, no light-induced degradation (LIDfree), no voltage-induced degradation (PIDfree), low temperature coefficient, high power generation, low light decay, low power generation cost and double-sided light power generation, which ensures more reliable photovoltaic modules, lower construction cost of power stations and longer service life, and is very suitable for distributed photovoltaic applications, and is one of the mainstream technologies of high-efficiency cells. The double-sided heterojunction module can output more than 20% of power under the reflection of white background. According to the field test, the double-sided HJT module can output 28.9% more power than the single-sided HJT module on average.

[0004] In the process of preparing HJT solar cells, PECVD plays the most important role in determining the performance of the product. The passivation layer deposited on the light entrance surface is intrinsic layer (i) and the boron-doped (p) layer is stacked on it, and the back surface also deposits intrinsic passivation layer (i) and stacks phosphorus-doped (n) layer, the thickness of the surface passivation layer i / p and i / n is about 15-25 nm. Then about 60-150 nm of transparent conductive film (TCO) is sputtered on the front and back surfaces, and at present, traditional sputtering ITO (indium tin oxide) is mostly used as transparent conductive layer (TCO) or RPD (reactive plasma deposition) technology is used to evaporate IWO (indium tungsten oxide) as transparent conductive film, then the front and back conductive wires can be made by silk printing low-temperature silver paste on the transparent conductive film, or the front and back conductive wires can be made by electroforming copper, so that the preparation of an HJT cell is completed.

[0005] The packaging of the HJT module has some defects, one is that the amorphous silicon or microcrystalline silicon layer will affect the passivation effect of the battery and reduce the efficiency under long-term ultraviolet irradiation, and the other is that the current packaging glass and transparent conductive film will still reflect part of the light, affecting the light incidence rate and causing the reduction of efficiency and power. Utility model content

[0006] The utility model adopts the technical scheme of a kind of heterojunction solar module, comprising:

[0007] Glass panel assembly, the glass panel assembly can cover the front and / or back of photovoltaic cell module;

[0008] The glass panel assembly includes a glass layer, a first coating layer and a second coating layer, the first coating layer is arranged on the side of the glass layer close to the photovoltaic cell module, and the second coating layer is arranged on the side of the first coating layer close to the photovoltaic cell module, wherein the refractive indexes of the glass layer, the first coating layer and the second coating layer increase in turn.

[0009] By arranging the first coating layer and the second coating layer in turn inside the glass layer with low refractive index, a three-layer anti-reflection structure composed of high, medium and low refractive index films is formed, which blocks the incidence of ultraviolet light, solving the problem that the amorphous silicon or microcrystalline silicon layer will affect the passivation effect of the battery and reduce the efficiency under long-term ultraviolet irradiation. And by arranging the three-layer anti-reflection structure, the amount of visible light and infrared light entering is increased, solving the problem that the current packaging glass and transparent conductive film will still reflect part of the light, affecting the light incidence rate and causing the reduction of efficiency and power. This helps to improve the CTM (the ratio of the output power of the module to the total power of the cell pieces) of the heterojunction solar module, and improve the efficiency and output power of the heterojunction solar module, improve the weather resistance and ensure the long-term reliability of the heterojunction solar module, which is conducive to the promotion of the market and the popularization of the product.

[0010] Further, the thickness of the first coating layer is 5-30 nm, and the refractive index is 1.7-2.0.

[0011] Further, the material of the first coating layer is selected from any one of zinc oxide doped with magnesium oxide, aluminum oxide, gallium oxide, silicon oxide, chromium oxide, zirconium oxide and silicon oxide.

[0012] Further, the thickness of the second coating layer is 5-20 nm, and the refractive index is 2.2-2.4.

[0013] Further, the material of the second coating layer is selected from any one of titanium oxide, niobium oxide, zirconium oxide and tantalum oxide.

[0014] Further, the material of the glass layer is low-iron ultra-white tempered glass, and the thickness of the glass layer is 2-4 mm.

[0015] Further, a water vapor barrier film layer is further included, which is arranged between the glass panel assembly and the photovoltaic cell assembly, the thickness of the water vapor barrier film layer is 0.01-3 mm, and the material is selected from any one of ethylene-vinyl acetate copolymer EVA, ethylene-octene copolymer POE and foamed polyethylene EPE.

[0016] Further, the photovoltaic cell assembly includes an N-type monocrystalline silicon wafer, and a transparent conductive layer arranged on the front surface and / or back surface of the N-type monocrystalline silicon wafer, the thickness of the transparent conductive layer is 50-150 nm, and the refractive index is 1.85-2.1.

[0017] Further, an intrinsic amorphous silicon layer is further included, which is arranged on the front surface and back surface of the N-type monocrystalline silicon wafer, the intrinsic amorphous silicon layer is arranged between the N-type monocrystalline silicon wafer and the transparent conductive layer, and the thickness of the intrinsic amorphous silicon layer is 5-25 nm.

[0018] Further, a conductive grid line is arranged on the side of the transparent conductive layer away from the N-type monocrystalline silicon wafer, the conductive grid line includes a fine grid line and a main grid line, the height of the fine grid line is 5-15 um, and the width is 10-40 um; the height of the main grid line is 5-15 um, and the width is 30-100 um.

[0019] The beneficial effects of the utility model are that: by arranging the first coating layer and the second coating layer in sequence on the inside of the glass layer with low refractive index, a three-layer anti-reflection structure composed of high, medium and low refractive index film layers is formed, the incidence of ultraviolet rays is blocked, and the light quantity of visible light and infrared light is improved, which helps to improve the HJT assembly CTM (the ratio of the total power of the assembly output power and the cell piece power), improves the efficiency and output power of the assembly, improves the weather resistance and ensures the long-term reliability of the HJT assembly, and is conducive to the promotion of the market and the popularization of the product. BRIEF DESCRIPTION OF DRAWINGS

[0020] The drawings constituting a part of the present application are used to provide a further understanding of the utility model, and the schematic embodiments of the utility model and the description thereof are used to explain the utility model, and do not constitute an improper limitation on the utility model.

[0021] In order to more clearly illustrate the technical scheme in the embodiments of the utility model, the drawings needed to be used in the embodiment description will be briefly introduced below, and obviously, the drawings in the following description are only some embodiments of the utility model, and other drawings can be obtained by those skilled in the art without creating labor on the premise.

[0022] Figure 1 It is a structure schematic view of the heterojunction solar module of the embodiment of the utility model.

[0023] In the figure: 1, photovoltaic cell module; 11, N-type monocrystalline silicon wafer; 12, intrinsic amorphous silicon layer; 13, microcrystalline silicon layer; 14, transparent conductive layer; 15, conductive grid line; 2, water vapor barrier film layer; 3, glass panel assembly; 31, glass layer; 32, first coating layer; 33, second coating layer. DETAILED DESCRIPTION

[0024] In order to make the above-mentioned purpose, features and advantages of the utility model more apparent and easy to understand, the specific embodiments of the utility model are described in detail below with reference to the drawings. In the following description, a large number of specific details are set forth in order to fully understand the utility model. However, the utility model can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without departing from the connotation of the utility model, so the utility model is not limited by the specific embodiments disclosed below.

[0025] In addition, the term "and / or" in this paper is only a description of the association relationship of the associated objects, which means that there may be three kinds of relationships, for example, A and / or B, which can represent the three cases of A alone, A and B together, and B alone. In addition, the character " / " in this paper generally represents an "or" relationship between the front and rear associated objects unless otherwise specified.

[0026] Referring to the drawings Figure 1 As shown in the drawings, the heterojunction solar module in the embodiment includes a glass panel assembly 3, which can cover the front and / or back of the photovoltaic cell module 1. The glass panel assembly 3 includes a glass layer 31, and further includes a first coating layer 32 and a second coating layer 33. The first coating layer 32 and the glass layer 32 are arranged in close contact on the side close to the photovoltaic cell module 1, and the second coating layer 33 and the first coating layer 32 are arranged in close contact on the side close to the photovoltaic cell module 1. The refractive indexes of the glass layer 31, the first coating layer 32 and the second coating layer 33 increase in turn.

[0027] For the packaging and manufacturing of the heterojunction solar module, ZnO series oxides are used as the first coating layer 32 and oxides with higher refractive indexes are used as the second coating layer 33 on the inner side of the packaging glass (low refractive index), forming a three-layer anti-reflection structure composed of high, medium and low refractive index film layers (glass layer 31, first coating layer 32 and second coating layer 33), effectively blocking the incidence of ultraviolet light and increasing the amount of visible light and infrared light entering the light, improving the efficiency and output power of the module, improving the weather resistance and ensuring the long-term reliability of the HJT module, which is conducive to the promotion of the market and the popularization of the product.

[0028] In some embodiments, the photovoltaic cell assembly 1 comprises an N-type monocrystalline silicon wafer 11, and an intrinsic amorphous silicon layer 12 and a microcrystalline silicon layer 13 are sequentially arranged on the front and back surfaces of the N-type monocrystalline silicon wafer 11, wherein the microcrystalline silicon layer 13 comprises a front N-type microcrystalline silicon layer arranged on the front surface of the cell wafer and a P-type microcrystalline silicon layer arranged on the back surface of the cell wafer. The intrinsic amorphous silicon layer 12 has a thickness of 5-25 nm, the front N-type microcrystalline silicon layer has a thickness of 5-25 nm, and the back P-type microcrystalline silicon layer has a thickness of 5-25 nm.

[0029] In some embodiments, a transparent conductive layer 14 is arranged on the front N-type microcrystalline silicon layer and the P-type microcrystalline silicon layer film layer, the transparent conductive layer 14 has a thickness of 50-150 nm and a refractive index of 1.85-2.1. Specifically, when sputtering the transparent conductive layer 14 on the front and back surfaces, the sputtering cavity is pumped to a pressure of 0.7×10 -5 -0.9×10 -5 torr after vacuum pumping, argon is used as the working gas, and the working pressure of the sputtering cavity is controlled to 3×10 -3 torr by a throttle valve, and a 50-150 nm thick ITO or IZTO film layer is sputtered on the P-type and N-type microcrystalline silicon film layers on the front and back surfaces by using a high-purity AZO, ITO, or IZTO target (purity 99.95%) and a pulsed direct current power supply, thereby completing the plating of the transparent conductive layer 14 on the front and back surfaces. Alternatively, a high-purity GZO, ICO, or IWO block (purity 99.95%) is used, and a RPD device is used to vacuum pump to a pressure of 0.5×10 -5 -0.7×10 - 5 torr, and a 50-150 nm thick transparent conductive layer 14 is directly evaporated on the P-type and N-type microcrystalline silicon layers on the front and back surfaces by using a GZO, ICO, or IWO material, thereby completing the plating of the transparent conductive layer 14 on the front and back surfaces. The resistivity of the transparent conductive layer 14 is <5×10 -4 Ωcm.

[0030] In some embodiments, a low-temperature silver paste or a low-temperature silver-coated copper paste is used as the material for the transparent conductive layer 14 away from the N-type monocrystalline silicon wafer, and a screen printing machine is used to print a conductive grid line 15, which comprises a fine grid line and a main grid line, and the height of the grid line is 5-20 um and the width is 30-60 um; the height of the main grid line is 60-120 um, and the resistivity is <3x10 -5 Ωcm. Alternatively, an ink mask, a yellow light process, and an electroplating process are used to make an electroplated copper grid line, the width of the fine grid is 10-25 um, the width of the main grid is 30-100 um, and the height of the grid line is 5-20 um. The resistivity is <6x10 -6 Ωcm.

[0031] In some embodiments, the sputtering chamber is pumped to a pressure of 0.7x10 -5 -0.9x10 -5 torr, and then argon gas is used as the working gas to control the working pressure of the sputtering chamber to 3x10 - 3 torr through a throttle valve. Zinc oxide-doped magnesium oxide, aluminum oxide, gallium oxide, silicon oxide, chromium oxide, zirconium oxide, silicon oxide, etc. are used as target materials to sputter a 5-30 nm first coating layer 32 on the glass layer 31 by a pulsed direct current power supply. The first coating layer 32 serves as an ultraviolet blocking layer, and the refractive index is about 1.7-2.0.

[0032] In some embodiments, the sputtering chamber is pumped to a pressure of 0.7x10 -5 -0.9x10 -5 torr, and then argon gas is used as the working gas to control the working pressure of the sputtering chamber to 5x10 - 3 torr through a throttle valve. High-refractive-index materials such as titanium oxide, niobium oxide, zirconium oxide, and tantalum oxide are used as target materials to sputter a 5-20 nm second coating layer 33 on the first coating layer 32 on the front and back glass surfaces by a pulsed direct current power supply. The refractive index is about 2.2-2.4.

[0033] The inner side of the encapsulating glass (low-refractive-index layer) uses ZnO series oxides as the first coating layer 32 and higher-refractive-index oxides as the second coating layer 33 to form a three-layer antireflection structure composed of high, medium, and low refractive index film layers, block the incidence of ultraviolet light, and increase the amount of visible and infrared light entering, which helps to improve the CTM of HJT modules, improves the efficiency and output power of the modules, improves the weather resistance, and ensures the long-term reliability of HJT modules, which is conducive to market promotion and product popularization.

[0034] In some embodiments, a water vapor barrier film layer 2 is further included, which is arranged between the glass panel assembly and the photovoltaic cell assembly 1. The thickness of the water vapor barrier film layer 2 is 0.01-3 mm, and the material is selected from any one of EVA, POE, and EPE.

[0035] When the module is a heterojunction solar module, first, the photovoltaic glass (glass panel assembly 3) with two layers of antireflection coating is laid on the water vapor barrier film layer 2, then the photovoltaic cell assembly 1 is laid on the water vapor barrier film layer 2, and then the photovoltaic glass (glass panel assembly 3) with two layers of antireflection coating on the inner surface is laid on the water vapor barrier film layer 2. Then, the structure is placed in a laminator to be laminated at a vacuum degree of less than 100 Pa and a temperature of about 130-150°C for 10-20 minutes to form a preliminary heterojunction solar module.

[0036] After the above process is completed, the frame, the terminal box are assembled, and after performance test, the heterojunction solar cell module is completed.

[0037] The above implementation manners are only for illustrating the technical concept and characteristics of the present application, and the purpose is to enable those skilled in the art to understand the content of the present application and implement it, and cannot limit the protection scope of the present application, and any equivalent changes or modifications made according to the spirit and essence of the present application should be covered within the protection scope of the present application.

[0038] In addition, it should be noted that each specific technical feature described in the above specific embodiments can be combined in any appropriate manner without contradiction, and in order to avoid unnecessary repetition, the present application will not further describe various possible combination manners.

Claims

1. A heterojunction solar module, characterized by, The application relates to a glass panel assembly (3) capable of covering the front and / or back of a photovoltaic cell assembly (1). The glass panel assembly (3) comprises a glass layer (31), a first coating layer (32) arranged on the side of the glass layer (31) close to the photovoltaic cell assembly (1), and a second coating layer (33) arranged on the side of the first coating layer (32) close to the photovoltaic cell assembly (1), wherein the refractive indexes of the glass layer (31), the first coating layer (32) and the second coating layer (33) increase in sequence. The thickness of the first coating layer (32) is 5-30 nm, and the refractive index is 1.7-2.

0.

2. The heterojunction solar module of claim 1, wherein, The material of the first coating layer (32) is selected from any one of zinc oxide doped magnesium oxide, aluminum oxide, gallium oxide, silicon oxide, chromium oxide, zirconium oxide and silicon oxide.

3. The heterojunction solar module of claim 1, wherein, The thickness of the second coating layer (33) is 5-20 nm, and the refractive index is 2.2-2.

4.

4. The heterojunction solar module of claim 1, wherein, The material of the second coating layer (33) is selected from any one of titanium oxide, niobium oxide, zirconium oxide and tantalum oxide.

5. The heterojunction solar module of claim 1, wherein, The material of the glass layer (31) is low-iron ultra-white tempered glass, and the thickness of the glass layer (31) is 2-4 mm.

6. The heterojunction solar module of claim 1, wherein, A water vapor barrier film layer (2) is arranged between the glass panel assembly (3) and the photovoltaic cell assembly (1), the thickness of the water vapor barrier film layer (2) is 0.01-3 mm, and the material is selected from any one of EVA, POE and EPE.

7. The heterojunction solar module of claim 1, wherein, The photovoltaic cell assembly (1) comprises an N-type monocrystalline silicon wafer (11) and a transparent conductive layer (14) arranged on the front and / or back of the N-type monocrystalline silicon wafer (11), the thickness of the transparent conductive layer (14) is 50-150 nm, and the refractive index is 1.85-2.

1.

8. The heterojunction solar module according to any of claims 1 to 7, characterized in that An intrinsic amorphous silicon layer (12) is arranged on the front and back of the N-type monocrystalline silicon wafer (11), the intrinsic amorphous silicon layer (12) is arranged between the N-type monocrystalline silicon wafer (11) and the transparent conductive layer (14), and the thickness of the intrinsic amorphous silicon layer (12) is 5-25 nm.

9. The heterojunction solar module of claim 8, wherein, A conductive grid line (15) is arranged on the side of the transparent conductive layer (14) away from the N-type monocrystalline silicon wafer (11), the conductive grid line (15) comprises fine grid lines and main grid lines, the height of the fine grid lines is 5-15 um, and the width is 10-40 um; the height of the main grid lines is 5-15 um, and the width is 30-100 um.

10. The heterojunction solar module of claim 9, wherein, ​

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