A crystalline silicon solar cell structure with multiple output ports

Abstract

The present invention discloses a multi-output crystalline silicon solar cell structure, comprising a plurality of structural units arranged side by side on a substrate. Each structural unit comprises a multi-layer power generation structure composed of a plurality of independent low-power power generation units stacked together. Adjacent low-power power generation units are insulated from each other by an insulating layer. The width of the multiple low-power power generation units and the insulating layer gradually decreases from bottom to top, so that the cross-section of each structural unit is an isosceles trapezoid with a narrow top and a wide bottom. Each low-power power generation unit is provided with a set of output ports. A focusing baffle is provided between adjacent structural units. The focusing baffle is composed of a plano-convex lens area, a buffer area, and a support area, from top to bottom. The focusing baffle is embedded between adjacent structural units through the support area, and is used to focus incident light between the two adjacent structural units for multiple reflection. The battery is easy to use and can provide electricity for small and micro-power applications without cutting the battery chip.

Description

Technical Field

[0001] The present invention relates to the field of photovoltaic power generation, and in particular to a crystalline silicon solar cell structure with multiple output ports. Background Art

[0002] Photovoltaic power generation technology has become one of the most important renewable energy utilization methods. With the continued promotion and popularization of photovoltaic power generation technology, it also faces increasingly complex electricity demand. From a formal perspective, the basic power generation unit of various existing photovoltaic power generation systems is a single battery chip. If the actual power demand is less than the output power of a single battery chip, the single battery chip needs to be cut into smaller power generation units to solve the problem. If the actual power demand is greater than the output power of a single battery chip, multiple battery chips need to be connected in series or parallel (i.e., forming a battery module) to solve the problem.

[0003] In the above two application scenarios, the main problems with the method of cutting battery chips into smaller power generation units are: the cutting of battery chips will lead to waste of battery materials at and near the cuts and local functional failure of the battery chips (near the cuts), which requires post-processing of the battery chip cuts, resulting in increased process processing costs; the main problems with the method of connecting multiple battery chips in series and parallel to form a battery assembly are: if any local area of ​​any battery chip in the battery assembly fails, the battery chip will fail, which will cause changes in the output power of the entire battery assembly and further affect the stability of the power generation system. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a crystalline silicon solar cell structure with multiple output ports that is easy to use and can provide electric energy for small and micro power demand occasions without cutting the cell chip.

[0005] The technical solutions of the present invention are as follows:

[0006] A crystalline silicon solar cell structure with multiple output ports is characterized by comprising: a plurality of structural units arranged side by side on a substrate, each structural unit comprising a multi-layer power generation structure composed of a plurality of independent low-power power generation units stacked together; adjacent low-power power generation units are insulated from each other by an insulating layer; the widths of the plurality of low-power power generation units and the insulating layer gradually decrease from bottom to top, so that the cross-section of each structural unit is an isosceles trapezoid that is narrow at the top and wide at the bottom; symmetrical triangular coupling regions are provided on both sides of each low-power power generation unit for coupling incident light into each low-power power generation unit, thereby generating a waveguide effect in each low-power power generation unit; and each low-power power generation unit is provided with a set of output ports for independently supplying power to an external power consumer or for achieving electrical connection between each other;

[0007] A focusing baffle is provided between two adjacent structural units. The focusing baffle is composed of a plano-convex lens area, a buffer area and a support area from top to bottom, and is embedded between the two adjacent structural units through the support area. It is used to reduce the light shielding loss of the metal electrode on the top of each structural unit and to focus the incident light between the two adjacent structural units for multiple reflections.

[0008] As a further preference, the vertex angle between the two sides of the cross section of each structural unit is 54.74±5°, which is used to guide the light incident into the interior of the focusing partition to maintain a trend of propagating toward the bottom surface after continuous reflection on the surface of the structural unit, thereby reflecting onto the triangular coupling area of ​​each small-power power generation unit to produce optical coupling, and then be efficiently coupled into the battery layer of each small-power power generation unit.

[0009] As a further preference, each small-power power generation unit is electrically connected by a crystalline silicon cell layer and metal electrodes arranged on the upper and lower sides of the crystalline silicon cell layer; the metal electrode on the bottom surface of the small-power power generation unit located at the bottom layer is a flat electrode, and the remaining metal electrodes are all narrow strip electrodes.

[0010] As a further preference, the X-direction width L of the small-power power generation unit located at the bottom layer is 0.5 to 5 mm, and the crystalline silicon cell layer of each small-power power generation unit is trapezoidal and has a thickness of 0.5 μm to 70 μm, so that the output power of each small-power power generation unit located at the bottom layer is only 1 / 50 to 1 / 1000 of the output power of a traditional single cell chip, making its value equivalent to the power loss of the cut during the cutting process of traditional cell chips.

[0011] As a further preference, the focus of the plano-convex lens area in the focusing partition is located near the lower boundary of the buffer zone, so as to realize an absorption order of the incident light from top to bottom in the structural unit.

[0012] As a further preference, the focusing partition is made of EVA film light-transmitting insulating material.

[0013] As a further preference, the insulating layer is made of SiO2 film, which is used to form auxiliary coupling regions between two adjacent small-power power generation units, so that the incident light is continuously coupled into the small-power power generation units on the upper and lower sides of the insulating layer during the reflection process between the upper and lower surfaces of each insulating layer.

[0014] The beneficial effects of the present invention are:

[0015] 1. Since the crystalline silicon solar cell structure includes multiple structural units, each structural unit includes a multi-layer power generation structure composed of multiple small-power power generation units stacked together, and two adjacent small-power power generation units are insulated from each other by an insulating layer. Each small-power power generation unit is provided with a set of output terminals. Therefore, the output terminals of each small-power power generation unit can be used alone or in series-parallel combinations to provide electric energy for small and micro-power demand occasions. The minimum output power that can be provided by a single small-power power generation unit can reach or be less than 0.007W, avoiding the problems of battery material waste and increased process processing costs caused by the need to perform a cutting process on the battery chip to obtain small and micro-power.

[0016] 2. Since the width of the multiple small-power power generation units and the insulating layer gradually decreases from bottom to top, the cross-section of each structural unit is an isosceles trapezoid that is narrow at the top and wide at the bottom. Symmetrical triangular coupling regions are provided on both sides of each small-power power generation unit, so that the incident light can be coupled into each small-power power generation unit, so that each small-power power generation unit produces a waveguide effect, thereby ensuring the power generation efficiency of each small-power power generation unit.

[0017] 3. Since a focusing baffle is provided between two adjacent structural units, the focusing baffle is composed of a plano-convex lens area, a buffer area and a support area from top to bottom, and is embedded between the two adjacent structural units through the support area. The focusing baffle can focus the incident light between the two adjacent structural units, where it is reflected multiple times and propagates downward, thereby reflecting the incident light onto the triangular coupling area of ​​each small-power power generation unit, and can be efficiently coupled into each small-power power generation unit, thereby improving the power generation efficiency.

[0018] 4. After the battery structure is encapsulated, since each small-power power generation unit is provided with a set of output terminals, the output terminals of each small-power power generation unit can be adjusted and replaced from the outside. That is, after a single small-power power generation unit fails, it can be corrected and eliminated by adjusting and replacing the connection method of the output terminals of each small-power power generation unit without significantly affecting the output power of the entire battery structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a structural schematic diagram of the present invention.

[0020] Figure 2 yes Figure 1 AA cross-sectional view.

[0021] Figure 3 It is a structural schematic diagram of a structural unit of the present invention.

[0022] Figure 4 It is a schematic diagram of the waveguide of the present invention in which the incident light is focused by the focusing partition and then propagates and forms multi-mode transmission in the crystalline silicon cell layer.

[0023] Figure 5 These are two structural schematic diagrams of crystalline silicon battery layers.

[0024] In the figure: substrate 1, small power generation unit 2, insulating layer 3, crystalline silicon cell layer 4, metal electrode 5, focusing partition 6, plano-convex lens area 61, buffer area 62, support area 63, output end 7. DETAILED DESCRIPTION

[0025] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present invention.

[0026] like Figure 1-4 As shown, the present invention relates to a crystalline silicon solar cell structure with multiple output ports, comprising a plurality of structural units arranged side by side on a substrate 1. This embodiment uses five structural units as an example. Each structural unit comprises a multi-layer power generation structure composed of multiple independent low-power power generation units 2 stacked together. Adjacent low-power power generation units 2 are insulated from each other by a deposited insulating layer 3. The widths of the multiple low-power power generation units 2 and the insulating layer 3 gradually decrease from bottom to top, giving each structural unit a cross-section that is an isosceles trapezoid with a narrow top and a wide bottom. Symmetrical triangular coupling regions 401 are provided on either side of each low-power power generation unit 2 for coupling incident light into each low-power power generation unit 2, thereby generating a waveguide effect in each low-power power generation unit. Each low-power power generation unit 2 is provided with a set of output terminals 7 for independently supplying power to an external power consumer or for achieving electrical connection between each other. This embodiment uses three low-power power generation units 2 as an example for each structural unit.

[0027] The substrate 1 is made of materials such as glass, ceramic or silicon wafer; the insulating layer 3 is made of an insulating medium such as SiO2 film, SiNx film, Al2O3 film or EVA film, and is preferably a SiO2 film. Since the refractive index difference between the insulating layer 3 and the focusing partition 6 is very small, an auxiliary coupling zone can be formed between two adjacent small-power power generation units 2, so that the incident light is continuously coupled into the crystalline silicon cell layer 4 in the small-power power generation unit 2 on the upper and lower sides of the insulating layer 3 during the reflection process between the upper and lower surfaces of each insulating layer 3, thereby improving the photoelectric conversion efficiency.

[0028] A focusing baffle 6 is provided between each adjacent structural unit. The length of the focusing baffle 6 and the structural unit is equivalent to the length of the substrate 1. The focusing baffle 6 is composed of three parts from top to bottom: a plano-convex lens area 61, a buffer area 62, and a support area 63. The buffer area 62 has a rectangular cross-section, and the support area 63 has an isosceles triangle cross-section. The focusing baffle 6 is embedded between the two adjacent structural units through the support area 63 to reduce the light shielding loss of the metal electrode at the top of each structural unit. The incident light is focused between the two adjacent structural units, where it is reflected multiple times and then reflected onto the crystalline silicon cell layer 4 on both sides of the multiple low-power power generation units 2 in each structural unit, realizing the photoelectric conversion process.

[0029] The vertex angle α between the two sides of the cross section of each structural unit is 54.74±5°, which is used to guide the sunlight incident on the inside of the focusing partition 6 to maintain a trend of propagating toward the bottom surface after continuous reflection on the surface of the structural unit, thereby reflecting on the triangular coupling area 401 of each small-power power generation unit 2 to produce optical coupling, and then be efficiently coupled into the crystalline silicon cell layer 4 of each small-power power generation unit 2.

[0030] Each small power generation unit 2 is formed by electrically connecting a crystalline silicon cell layer 4 located in the middle and metal electrodes 5 located in the middle of the upper and lower sides of the crystalline silicon cell layer 4; the triangular coupling region 401 is located on both sides of the crystalline silicon cell layer 4, and the output end 7 is a metal wire and is respectively connected to the metal electrodes 5 on the upper and lower sides of the crystalline silicon cell layer 4. The metal electrode 5 on the bottom surface of the small power generation unit 2 at the bottom layer is a flat electrode, and the other metal electrodes 5 are all narrow strip electrodes. The crystalline silicon cell layer 4 is a pin-type cell structure from top to bottom or from bottom to top, such as Figure 5 The metal electrodes 5 are made of metal materials such as Ag, Al, Au or Cu, and are used to supply power to external power-consuming objects or to achieve electrical connections between each other.

[0031] The X-direction width L of the small-power power generation unit 2 located at the bottom layer in each structural unit is 0.5 to 5 mm, and the cross-section of the crystalline silicon battery layer 4 of each small-power power generation unit 2 is trapezoidal and has a thickness of 0.5 μm to 70 μm, so that the output power of each small-power power generation unit 2 located at the bottom layer is only 1 / 50 to 1 / 1000 of the output power of a traditional single battery chip, making its value equivalent to the power loss of the cut during the cutting process of traditional battery chips.

[0032] The focusing baffle 6 is made of a light-transmitting insulating material such as SiO2 film, SiNx film, Al2O3 film, or EVA film, preferably EVA film. The focal point O of the plano-convex lens region of the focusing baffle is located near the lower boundary of the buffer zone, thereby achieving a top-to-bottom absorption order for the incident light within the structural unit.

[0033] The height H of the plano-convex lens area 61 L L / 20≤H L ≤L / 2; the height H of the buffer zone 62 is 0≤H≤L / 2, which is used to adjust the focus of the plano-convex lens area 61 to near the lower boundary of the buffer zone.

[0034] The preparation process of the crystalline silicon solar cell structure is as follows;

[0035] 1. Deposit a metal electrode layer on the substrate 1 or the previously grown insulating layer 3, controlling its thickness to be 50 nm to 200 nm;

[0036] 2. Photolithography and etching of the metal electrode layer to control its width from 50nm to 200nm to obtain the lower electrode of the specified size of the small power generation unit;

[0037] 3. Deposit n-type or p-type high-concentration (N≥1019atom / cm3) silicon layer; deposit n-type or p-type low-concentration (1016atom / cm3≤N≤5×1017atom / cm3) silicon layer; deposit high-concentration (N≥1019atom / cm3) p-type or n-type high-concentration silicon layer;

[0038] 4. Photolithography and etching of the silicon layer (determine the X-axis lateral size according to the designed output power) to obtain a crystalline silicon cell layer 4 of the designed size;

[0039] 5. Deposit the metal electrode layer and control its thickness to 50nm~200nm;

[0040] 6. Photolithography and etching of the metal electrode layer to control its width from 50nm to 200nm to obtain the upper electrode of the specified size of the small power generation unit;

[0041] 7. Deposit an insulating layer and control its thickness to 1nm to 60nm.

[0042] 8. Repeat steps 1-7 to complete the multi-layer processing of the battery structure;

[0043] 9. The focusing partition is made by deposition or hot melting, and the plano-convex lens area is made by embossing process.

[0044] During operation, parallel light incident along the Z direction perpendicular to the cell structure and entering the focusing partition 6 is refracted and transmitted through the plano-convex lens area 61, and then converges between two adjacent structural units to undergo multiple reflections, and is reflected at different angles onto the crystalline silicon cell layers 4 on both sides of multiple small-power power generation units in each structural unit. Through the triangular coupling area 401 formed on both sides of each small-power power generation unit, it is coupled into the crystalline silicon cell layer 4 of each small-power power generation unit to form a waveguide effect, thereby realizing the photoelectric conversion process.

[0045] The incident light entering the insulating layer between two adjacent low-power power generation units in each structural unit can be continuously coupled into the crystalline silicon cell layer 4 in the low-power power generation units on the upper and lower sides of the insulating layer during the reflection process between the upper and lower surfaces of each insulating layer through the auxiliary coupling area formed by the insulating layer, because the refractive index difference between the insulating layer and the focusing partition 6 is very small, thereby forming a waveguide effect and repeating the photoelectric conversion process.

[0046] Although the embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the description and implementation methods. They can be fully applied to various fields suitable for the present invention. For those familiar with the art, additional modifications can be easily implemented. Therefore, without departing from the general concept defined by the claims and the scope of equivalents, the present invention is not limited to the specific details and illustrations shown and described herein.

Claims

1. A crystalline silicon solar cell structure with multiple output ports, characterized by: The invention comprises a plurality of structural units arranged side by side on a substrate, each structural unit comprising a multi-layer power generation structure composed of a plurality of independent low-power power generation units stacked together. Adjacent low-power power generation units are insulated from each other by an insulating layer. The width of the plurality of low-power power generation units and the insulating layer gradually decreases from bottom to top, so that the cross-section of each structural unit is an isosceles trapezoid that is narrow at the top and wide at the bottom. Symmetrical triangular coupling regions are provided on both sides of each low-power power generation unit for coupling incident light into each low-power power generation unit, so that each low-power power generation unit produces a waveguide effect. Each low-power power generation unit is provided with a set of output terminals for independently supplying power to an external power user or for realizing electrical connection between each other. A focusing baffle is provided between each adjacent structural unit. The focusing baffle is composed of a plano-convex lens area, a buffer area, and a support area from top to bottom. The focusing baffle is embedded between the two adjacent structural units through the support area to reduce the light shielding loss of the metal electrode on the top of each structural unit and to focus the incident light between the two adjacent structural units for multiple reflections. Each small-power power generation unit is made up of a crystalline silicon cell layer and metal electrodes located on the upper and lower sides of the crystalline silicon cell layer. The metal electrode on the bottom surface of the small-power power generation unit at the bottom layer is a flat plate electrode, and the remaining metal electrodes are all narrow strip electrodes. The insulating layer is made of SiO2 film and is used to form auxiliary coupling regions between two adjacent low-power power generation units, so that the incident light is continuously coupled into the low-power power generation units on the upper and lower sides of the insulating layer during the reflection process between the upper and lower surfaces of each insulating layer; The light-concentrating partition is made of EVA film light-transmitting insulating material.

2. The multi-output-port crystalline silicon solar cell structure according to claim 1, characterized in that: The vertex angle between the two waists of the cross section of each structural unit is 54.74±5°, which is used to guide the light incident on the inside of the focusing partition to continue to propagate toward the bottom surface after continuous reflection on the surface of the structural unit, thereby causing light coupling at the surface of the triangular coupling area of ​​each small-power power generation unit.

3. The multi-output-port crystalline silicon solar cell structure according to claim 1, characterized in that: The X-axis width L of the small-power power generation unit at the bottom layer is 0.5 to 5 mm. The crystalline silicon cell layer of each small-power power generation unit is trapezoidal and has a thickness of 0.5 μm to 70 μm. As a result, the output power of each small-power power generation unit at the bottom layer is only 1 / 50 to 1 / 1000 of the output power of a traditional single cell chip, which is equivalent to the power loss of the cut during the cutting process of traditional cell chips.

4. The multi-output-port crystalline silicon solar cell structure according to claim 1, characterized in that: The focus of the plano-convex lens area in the focusing partition is located near the lower boundary of the buffer zone, which is used to realize the absorption order of the incident light from top to bottom in the structural unit.

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