Gallium arsenide solar cell and preparation method thereof

Abstract

The invention provides a gallium arsenide solar cell and a preparation method thereof, and the preparation method comprises the following steps: depositing an antireflection film system, one side, close to a cell substrate, of the antireflection film system has conductivity, and the other side of the antireflection film system has insulativity; according to an upper electrode grid line pattern, etching one side, with insulativity, of the antireflection film system; evaporating an upper electrode grid line; and welding the welding spots. The method has the beneficial effects that the welding spot overlay and welding spot corrosion procedures are omitted, the production efficiency is improved, and the production cost is reduced.

Description

Technical Field

[0001] The invention belongs to the field of semiconductor technology, and in particular relates to a gallium arsenide solar cell and a preparation method thereof. Background Art

[0002] In order to achieve the ideal photoelectric conversion efficiency, a gallium arsenide solar cell usually evaporates a layer of anti-reflection film on the upper electrode grid line to improve the photoelectric efficiency by reducing the refraction of light. Since the anti-reflection film evaporated on the upper electrode grid line covers the solder joint position, it is necessary to perform overlay to remove the anti-reflection film at the solder joint position to achieve solderable interconnection. In the process of preparing solar cells, each additional photolithography and etching will increase the preparation cost of the solar cell. Therefore, in order to meet the growing low-cost demand for gallium arsenide solar cells, the present invention provides a gallium arsenide solar cell and a preparation method thereof. Summary of the invention

[0003] In order to solve the above technical problems, the present invention provides a gallium arsenide solar cell and a preparation method thereof, which effectively solves the problem of high preparation cost of gallium arsenide solar cells and overcomes the shortcomings of the prior art.

[0004] The technical solution adopted by the present invention is: a method for preparing a gallium arsenide solar cell, comprising the following steps:

[0005] Depositing an anti-reflection film system, wherein the anti-reflection film system has a conductive side close to the battery substrate and an insulating side;

[0006] According to the upper electrode grid line pattern, etching the insulating side of the anti-reflection film system;

[0007] Evaporating the upper electrode grid line;

[0008] Solder the solder joints.

[0009] Furthermore, the step of depositing the anti-reflection film system includes depositing an ITO film layer and evaporating an anti-reflection film layer, wherein the ITO film layer is deposited on the battery substrate, and the anti-reflection film layer is evaporated on the ITO film layer.

[0010] Furthermore, the thickness of the ITO film layer is 1 nm to 1000 nm, and the thickness of the anti-reflection film layer is 1 nm to 1000 nm.

[0011] Furthermore, the anti-reflection film layer is configured as a single layer or a multi-layer structure, and is one or more of aluminum oxide, titanium oxide, and magnesium fluoride.

[0012] Further, the step of etching the insulating side of the anti-reflection film system according to the pattern of the upper electrode grid line includes the following steps:

[0013] Photolithography of the upper electrode grid line pattern;

[0014] Removing the anti-reflection film layer in the upper electrode grid line pattern;

[0015] Furthermore, in the step of removing the anti-reflection film layer in the upper electrode grid line pattern, wet etching or dry etching is adopted.

[0016] Furthermore, the soaking time of the wet etching is 10s to 10min, and the ventilation time of the dry etching is 10s to 30min.

[0017] Furthermore, the step of evaporating between the upper electrode grid line and the welding pad also includes: removing the photoresist.

[0018] Furthermore, in the step of removing the photoresist, a degumming solution is used for immersion, the immersion time is 10 minutes to 120 minutes, and the degumming solution uses an organic solvent.

[0019] The present invention also provides a gallium arsenide solar cell, which is prepared by the preparation method described above.

[0020] The advantages and positive effects of the present invention are as follows: due to the adoption of the above technical solution, the processes of overlaying solder joints and corroding solder joints are eliminated, the production efficiency is improved, and the production cost is reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 The present invention is a process flow chart of a method for preparing a gallium arsenide solar cell according to an embodiment of the present invention.

[0022] Figure 2 It is a schematic diagram of a cell substrate of a method for preparing a gallium arsenide solar cell according to an embodiment of the present invention.

[0023] Figure 3 It is a schematic diagram of depositing an ITO film layer in a method for preparing a gallium arsenide solar cell according to an embodiment of the present invention.

[0024] Figure 4 It is a schematic diagram of depositing a basic film layer in a method for preparing a gallium arsenide solar cell according to an embodiment of the present invention.

[0025] Figure 5 The present invention is a schematic diagram of a method for preparing a gallium arsenide solar cell by photolithography of an electrode grid line pattern.

[0026] Figure 6 The present invention is a schematic diagram of a method for preparing a gallium arsenide solar cell in which a basic film layer in an upper electrode grid line pattern is removed.

[0027] Figure 7 The present invention is a schematic diagram of a method for preparing a gallium arsenide solar cell by evaporating an upper electrode grid line.

[0028] Figure 8 The present invention is a schematic diagram of removing photoresist in a method for preparing a gallium arsenide solar cell according to an embodiment of the present invention.

[0029] In the figure:

[0030] 1. Battery substrate 2. ITO film 3. Anti-reflection film

[0031] 4. Photoresist 5. Upper electrode grid line DETAILED DESCRIPTION

[0032] The embodiment of the present invention provides a gallium arsenide solar cell and a method for preparing the same. The embodiment of the present invention is described below in conjunction with the accompanying drawings.

[0033] In the description of the embodiments of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "top", "bottom", etc. is based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "set" and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected, or indirectly connected through an intermediate medium, or it can be a connection between the two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood by specific circumstances.

[0034] The present invention discloses a method for preparing a gallium arsenide solar cell, comprising the following steps: depositing an anti-reflection film system, wherein the side of the anti-reflection film system close to the cell substrate 1 is conductive, and the other side is insulating; etching the insulating side of the anti-reflection film system according to the upper electrode grid line pattern; evaporating the upper electrode grid line 5; and welding the solder joints. The anti-reflection film of the prior art only has insulating properties, and is deposited after the upper electrode grid line 5 is prepared, covering the upper electrode grid line 5. Overlay and corrosion are required when welding the solder joints. In the present embodiment, the anti-reflection film system is deposited first, and then the upper electrode grid line 5 is evaporated, so that the upper electrode grid line 5 will not be covered. When welding the solder joints, overlay and corrosion are not required, thereby reducing the production cost.

[0035] Specifically, the deposited anti-reflection film system includes depositing an ITO film layer 2 and evaporating an anti-reflection film layer 3. The anti-reflection film system consists of an ITO film layer 2 and an anti-reflection film layer 3. The ITO film layer 2 is conductive and is deposited on the battery substrate 1. The anti-reflection film layer 3 is insulating and is evaporated on the ITO film layer 2.

[0036] Specifically, according to the pattern of the upper electrode grid line 5, etching the insulating side of the anti-reflection film system includes the following steps:

[0037] The upper electrode grid line pattern is photoetched, and the upper surface of the anti-reflection film layer 3 is subjected to glue application, exposure and development to obtain the upper electrode grid line pattern.

[0038] The anti-reflection film layer 3 in the upper electrode grid line pattern is removed to facilitate the evaporation of the upper electrode grid line 5 .

[0039] Specifically, the deposition between the upper electrode grid line 5 and the welding pad also includes: removing the photoresist 4. After the upper electrode grid line 5 is deposited, a layer of grid line metal is also covered at the non-upper electrode grid line pattern. By removing the photoresist 4, the grid line metal covering the non-upper electrode grid line pattern is removed.

[0040] like Figure 1 As shown, the process flow of a method for preparing a gallium arsenide solar cell according to an embodiment of the present invention includes the following steps:

[0041] S1, preparing a battery matrix 1;

[0042] S2, depositing ITO film layer 2;

[0043] S3, evaporation anti-reflection film layer 3;

[0044] S4, photolithography of the upper electrode grid line pattern;

[0045] S5, removing the anti-reflection film layer 3 in the upper electrode grid line pattern;

[0046] S6, evaporating the upper electrode grid line 5;

[0047] S7. Remove the photoresist 4.

[0048] S8. Weld the solder joints.

[0049] The following is a detailed introduction:

[0050] S1, preparing a battery matrix 1;

[0051] like Figure 2 As shown, the device process is used to prepare the battery substrate 1, so that the battery substrate 1 reaches the state to be deposited with the ITO film layer 2. The device process is a prior art and will not be described in detail here.

[0052] S2, depositing ITO film layer 2;

[0053] like Figure 3As shown, magnetron sputtering or evaporation can be used to deposit an ITO film 2 on the surface of the battery substrate 1. The ITO film 2, as a guide medium layer, can form a good ohmic contact with the battery substrate 1 and the upper electrode grid line 5. The thickness of the ITO film 2 is 1nm to 1000nm.

[0054] S3, evaporation anti-reflection film layer 3;

[0055] like Figure 4 As shown, an anti-reflection film layer 3 is deposited on the surface of the ITO film layer 2 by evaporation with the ITO film layer 2 as the base layer. The thickness of the anti-reflection film layer 3 is 1nm to 1000nm. The anti-reflection film layer 3 is set to a single layer or multilayer structure, and is one or more of aluminum oxide, titanium oxide, and magnesium fluoride.

[0056] S4, photolithography of the upper electrode grid line pattern;

[0057] like Figure 5 As shown, glue is applied on the surface of the anti-reflection film layer 3, and a photolithography machine and a photomask are used to expose and develop the photoresist 4 to obtain an upper electrode grid line pattern.

[0058] S5, removing the anti-reflection film layer 3 in the upper electrode grid line pattern;

[0059] like Figure 6 As shown, according to the obtained upper electrode grid line pattern, the anti-reflection film layer 3 is removed by wet etching or dry etching.

[0060] Wet etching uses acid and alkali solutions for immersion corrosion. Acid solutions such as hydrofluoric acid or sulfuric acid can be used, and alkaline solutions such as sodium hydroxide or ammonia water can also be used. The immersion time is 10s to 10min. There is no limit on the specific concentration. The higher the concentration, the shorter the immersion time, and the lower the concentration, the longer the immersion time.

[0061] In dry etching, etching gas is introduced into the reaction chamber for etching, and the ventilation time is 10s to 30min.

[0062] The solution or gas used to remove the anti-reflection film layer 3 will not damage the ITO film layer 2 .

[0063] S6, evaporating the upper electrode grid line 5;

[0064] like Figure 7 As shown, the battery is placed in a vacuum chamber to perform vapor deposition of the upper electrode grid line 5. A layer of grid line metal is deposited at the upper electrode grid line pattern and at the non-upper electrode grid line pattern.

[0065] S7, removing the photoresist 4;

[0066] like Figure 8As shown, the photoresist 4 is removed by soaking in a degumming liquid, and the gate line metal covering the non-upper electrode gate line pattern is removed. The degumming liquid is an organic solvent, and alcohol, acetone or phenol can be used. The soaking time is 10 minutes to 120 minutes.

[0067] S8, welding solder joints;

[0068] The solder joints can be directly welded without overlay and corrosion.

[0069] A gallium arsenide solar cell is prepared by the preparation method as described above. An ITO film layer 2 is provided on the surface of a cell substrate 1, and an anti-reflection film layer 3 is provided on the ITO film layer 2. The ITO film layer 2 and the anti-reflection film layer 3 form an anti-reflection film system. An upper electrode grid line pattern is provided on the anti-reflection film layer 3, and an upper electrode grid line 5 is provided in the upper electrode grid line 5 pattern, and welding points are directly welded on the upper electrode grid line 5 without overlay.

[0070] Embodiment 1: A method for preparing a gallium arsenide solar cell, comprising the following steps:

[0071] S1, preparing a battery substrate 1; adopting a device process to prepare the battery substrate 1, so that the battery substrate 1 reaches a state where an ITO film layer 2 is to be deposited.

[0072] S2, depositing an ITO film layer 2: using a magnetron sputtering method, depositing an ITO film layer 2 on the surface of the battery substrate 1. The thickness of the ITO film layer 2 is 100 nm.

[0073] S3, evaporating an anti-reflection film layer 3: using an evaporation method, evaporating an anti-reflection film layer 3 on the surface of the ITO film layer 2. The thickness of the anti-reflection film layer 3 is 80nm. The anti-reflection film layer 3 is set as a single layer of aluminum oxide.

[0074] S4, photolithography of the upper electrode grid line pattern; applying glue on the surface of the anti-reflection film layer 3, exposing and developing the photoresist 4 using a photolithography machine and a photomask, and obtaining the upper electrode grid line pattern.

[0075] S5, removing the anti-reflection film layer 3 in the upper electrode grid line pattern; soaking in hydrofluoric acid for 1 minute to corrode the anti-reflection film layer 3 in the upper electrode grid line pattern.

[0076] S6, evaporating the upper electrode grid line 5: placing the battery in a vacuum chamber to evaporate the upper electrode grid line 5. A layer of grid line metal is deposited at the upper electrode grid line pattern and at the non-upper electrode grid line pattern.

[0077] S7, removing the photoresist 4; soaking in an alcohol organic solvent for 10 minutes to remove the gate line metal at the non-upper electrode gate line pattern.

[0078] S8. Weld the solder joints.

[0079] Embodiment 2: A method for preparing a gallium arsenide solar cell, comprising the following steps:

[0080] S1, preparing a battery substrate 1; adopting a device process to prepare the battery substrate 1, so that the battery substrate 1 reaches a state where an ITO film layer 2 is to be deposited.

[0081] S2, depositing ITO film layer 2: using evaporation method, depositing ITO film layer 2 on the surface of battery substrate 1. The thickness of ITO film layer 2 is 500nm

[0082] S3, evaporating an anti-reflection film layer 3: using an evaporation method, evaporating an anti-reflection film layer 3 on the surface of the ITO film layer 2. The anti-reflection film layer 3 is set to be a double layer of titanium oxide, and the thickness of each layer is 200nm.

[0083] S4, photolithography of the upper electrode grid line pattern; applying glue on the surface of the anti-reflection film layer 3, exposing and developing the photoresist 4 using a photolithography machine and a photomask, and obtaining the upper electrode grid line pattern.

[0084] S5, removing the anti-reflection film layer 3 in the upper electrode grid line pattern; soaking in a sodium hydroxide solution for 5 minutes to corrode the anti-reflection film layer 3 in the upper electrode grid line pattern.

[0085] S6, evaporating the upper electrode grid line 5: placing the battery in a vacuum chamber to evaporate the upper electrode grid line 5. A layer of grid line metal is deposited at the upper electrode grid line pattern and at the non-upper electrode grid line pattern.

[0086] S7, removing the photoresist 4; soaking in acetone organic solvent for 20 minutes to remove the gate line metal at the non-upper electrode gate line pattern.

[0087] S8. Weld the solder joints.

[0088] Embodiment 3: A method for preparing a gallium arsenide solar cell, comprising the following steps:

[0089] S1, preparing a battery substrate 1; adopting a device process to prepare the battery substrate 1, so that the battery substrate 1 reaches a state where an ITO film layer 2 is to be deposited.

[0090] S2, depositing an ITO film layer 2: using an evaporation method, depositing an ITO film layer 2 on the surface of the battery substrate 1. The thickness of the ITO film layer 2 is 900 nm.

[0091] S3, evaporating an anti-reflection film layer 3: using an evaporation method, evaporating an anti-reflection film layer 3 on the surface of the ITO film layer 2. The anti-reflection film layer 3 is set as a double-layer structure, a layer close to the ITO film layer 2 is set as aluminum oxide with a thickness of 100nm, and the other layer is set as magnesium fluoride with a thickness of 400nm.

[0092] S4, photolithography of the upper electrode grid line pattern; applying glue on the surface of the anti-reflection film layer 3, exposing and developing the photoresist 4 using a photolithography machine and a photomask, and obtaining the upper electrode grid line pattern.

[0093] S5, removing the anti-reflection film layer 3 in the upper electrode grid line pattern; using dry etching, introducing etching gas into the reaction chamber to etch the anti-reflection film layer 3 in the electrode grid line pattern, and the ventilation time is 15 minutes.

[0094] S6, evaporating the upper electrode grid line 5: placing the battery in a vacuum chamber to evaporate the upper electrode grid line 5. Depositing a layer of grid line metal at the upper electrode grid line 5 pattern and at non-upper electrode grid line 5 pattern locations.

[0095] S7, removing the photoresist 4; soaking in a phenolic organic solvent for 60 minutes to remove the gate line metal at the non-upper electrode gate line pattern.

[0096] S8. Weld the solder joints.

[0097] The advantages and positive effects of the present invention are:

[0098] 1. The solder joints can be directly welded without the need for overlay process, thus reducing the number of photolithography processes;

[0099] 2. No need to corrode the solder joints, reducing the number of corrosion processes;

[0100] 3. Shortened the process time, improved work efficiency and reduced production costs.

[0101] The embodiments of the present invention are described in detail above, but the contents described are only preferred embodiments of the present invention and cannot be considered to limit the scope of implementation of the present invention. All equivalent changes and improvements made within the scope of the present invention should still fall within the scope of the patent coverage of the present invention.

Claims

1. A method for preparing a gallium arsenide solar cell, characterized in that: The following steps are involved: Depositing an anti-reflection film system, wherein the anti-reflection film system has a conductive side close to the battery substrate and an insulating side; According to the upper electrode grid line pattern, etching the insulating side of the anti-reflection film system; Evaporating the upper electrode grid line; Solder the solder joints.

2. The method for preparing a gallium arsenide solar cell according to claim 1, characterized in that: The step of depositing the anti-reflection film system includes depositing an ITO film layer and evaporating an anti-reflection film layer, wherein the ITO film layer is deposited on the battery substrate, and the anti-reflection film layer is evaporated on the ITO film layer.

3. The method for preparing a gallium arsenide solar cell according to claim 2, characterized in that: The thickness of the ITO film layer is 1 nm to 1000 nm, and the thickness of the anti-reflection film layer is 1 nm to 1000 nm.

4. The method for preparing a gallium arsenide solar cell according to claim 2, characterized in that: The anti-reflection film layer is set to a single layer or a multi-layer structure, and is one or more of aluminum oxide, titanium oxide, and magnesium fluoride.

5. A method for preparing a gallium arsenide solar cell according to any one of claims 2 to 4, characterized in that: The step of etching the insulating side of the anti-reflection film system according to the pattern of the upper electrode grid line includes the following steps: Photolithography of the upper electrode grid line pattern; The anti-reflection film layer in the upper electrode grid line pattern is removed.

6. The method for preparing a gallium arsenide solar cell according to claim 5, characterized in that: In the step of removing the anti-reflection film layer in the upper electrode grid line pattern, wet etching or dry etching is adopted.

7. The method for preparing a gallium arsenide solar cell according to claim 6, characterized in that: The soaking time of the wet etching is 10s to 10min, and the ventilation time of the dry etching is 10s to 30min.

8. A method for preparing a gallium arsenide solar cell according to any one of claims 1-4 and 6-7, characterized in that: The step of evaporating between the upper electrode grid line and the welding pad also includes: removing the photoresist.

9. The method for preparing a gallium arsenide solar cell according to claim 8, characterized in that: In the step of removing the photoresist, a degumming solution is used for immersion, the immersion time is 10 minutes to 120 minutes, and the degumming solution uses an organic solvent.

10. A gallium arsenide solar cell, characterized in that: The method is prepared by the method according to any one of claims 1 to 9.

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