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CN-122002964-A - Solar cell and preparation method thereof

CN122002964ACN 122002964 ACN122002964 ACN 122002964ACN-122002964-A

Abstract

The application relates to the technical field of solar cells, and mainly provides a solar cell and a preparation method thereof. The solar cell comprises a silicon substrate, a first intrinsic amorphous silicon layer and a first doped layer, wherein the silicon substrate is provided with a light incident surface and a light back surface which are oppositely arranged, the first intrinsic amorphous silicon layer and the first doped layer are positioned on the light incident surface and sequentially stacked along the direction far away from the silicon substrate, the first doped layer comprises a nano-crystalline silicon oxide layer, the second intrinsic amorphous silicon layer, the second doped layer and the second transparent conductive oxide layer are positioned on the light back surface and sequentially stacked along the direction far away from the silicon substrate, and the second doped layer comprises a first microcrystalline silicon oxycarbide layer, a second microcrystalline silicon oxycarbide layer and a third microcrystalline silicon oxycarbide layer which are sequentially stacked along the direction far away from the silicon substrate. The solar cell in the technical scheme is beneficial to migration of carriers and can improve current density and photoelectric conversion efficiency of the solar cell.

Inventors

  • Zhu Anzheng

Assignees

  • 天合光能股份有限公司

Dates

Publication Date
20260508
Application Date
20241107

Claims (13)

  1. 1. A solar cell, comprising: A silicon substrate having a light incident surface and a light back surface arranged opposite to each other; the first intrinsic amorphous silicon layer and the first doped layer are positioned on the light incident surface and sequentially laminated along the direction far away from the silicon substrate, wherein the first doped layer comprises a nanocrystalline silicon oxide layer; The second doped layer comprises a first microcrystalline silicon oxycarbide layer, a second microcrystalline silicon oxycarbide layer and a third microcrystalline silicon oxycarbide layer which are sequentially stacked along the direction far away from the silicon substrate, wherein the carbon-oxygen ratio of the first microcrystalline silicon oxycarbide layer, the second microcrystalline silicon oxycarbide layer and the third microcrystalline silicon oxycarbide layer is sequentially decreased; Wherein the doping types of the first doping layer and the second doping layer are different.
  2. 2. The solar cell according to claim 1, wherein the carbon-oxygen ratio of the first microcrystalline silicon oxycarbide layer is 0.6 to 0.8, the carbon-oxygen ratio of the second microcrystalline silicon oxycarbide layer is 0.4 to 0.6, and the carbon-oxygen ratio of the third microcrystalline silicon oxycarbide layer is 0.2 to 0.4.
  3. 3. The solar cell of claim 1, wherein the first microcrystalline silicon oxycarbide layer has a crystallization rate of 30% -40%, the second microcrystalline silicon oxycarbide layer has a crystallization rate of 15% -25%, and the third microcrystalline silicon oxycarbide layer has a crystallization rate of 35% -45%.
  4. 4. The solar cell according to claim 1, wherein, The first doping layer is a P-type doping layer, and the second doping layer is an N-type doping layer; The ratio of carbon, oxygen and phosphorus in the first microcrystalline silicon oxycarbide layer is (0.6-0.7): 1 (0.01-0.025), the ratio of carbon, oxygen and phosphorus in the second microcrystalline silicon oxycarbide layer is (0.45-0.55): 1 (0.025-0.045), and the ratio of carbon, oxygen and phosphorus in the third microcrystalline silicon oxycarbide layer is (0.2-0.3): 1 (0.045-0.06).
  5. 5. The solar cell according to claim 1, wherein the thickness of the first microcrystalline silicon oxycarbide layer, the second microcrystalline silicon oxycarbide layer, and the third microcrystalline silicon oxycarbide layer is each and independently 1-15nm.
  6. 6. The solar cell according to claim 1, wherein, The silicon-oxygen ratio of the nanocrystalline silicon oxide layer is 1.5-2, and/or The crystallization rate of the nanocrystalline silicon oxide layer is more than or equal to 25%.
  7. 7. The solar cell according to claim 1, wherein, The first doping layer is a P-type doping layer, and the second doping layer is an N-type doping layer; The boron doping concentration in the nanocrystalline silicon oxide layer is 1 multiplied by 10 19 -1×10 21 atom/cm 3 .
  8. 8. The solar cell according to any one of claims 1 to 7, further comprising: A first transparent conductive oxide layer and a first electrode which are positioned on the first doping layer and are sequentially laminated along the direction far away from the silicon substrate; and a second electrode positioned on one side of the second transparent conductive oxide layer away from the silicon substrate.
  9. 9. The solar cell of claim 8, wherein the first transparent conductive oxide layer comprises one or both of MoO x 、TeO x .
  10. 10. The solar cell of claim 8, further comprising: A metal layer, a long wave reflecting layer, an electron transport layer, a perovskite light absorption layer and a hole transport layer which are positioned between the first transparent conductive oxide layer and the first electrode and are sequentially laminated along the direction far away from the silicon substrate; wherein the thickness of the metal layer is 5-10nm, and the second electrode is a metal electrode and has a thickness of 50-200nm.
  11. 11. The solar cell of claim 10, wherein the long wave reflective layer comprises one or both of ZnO, srTiO 3 .
  12. 12. A method of manufacturing a solar cell, comprising: providing a silicon substrate, wherein the silicon substrate is provided with a light incident surface and a backlight surface which are oppositely arranged; Sequentially forming a first intrinsic amorphous silicon layer and a first doped layer on the light incident surface, wherein the first doped layer comprises a nanocrystalline silicon oxide layer; Sequentially forming a second intrinsic amorphous silicon layer, a first microcrystalline silicon oxycarbide layer, a second microcrystalline silicon oxycarbide layer, a third microcrystalline silicon oxycarbide layer and a second transparent conductive oxide layer on the backlight surface, wherein the first microcrystalline silicon oxycarbide layer, the second microcrystalline silicon oxycarbide layer and the third microcrystalline silicon oxycarbide layer form a second doped layer together, and the carbon-oxygen ratio of the first microcrystalline silicon oxycarbide layer, the second microcrystalline silicon oxycarbide layer and the third microcrystalline silicon oxycarbide layer is sequentially decreased; Wherein the doping types of the first doping layer and the second doping layer are different.
  13. 13. The method of manufacturing a solar cell according to claim 12, wherein the method of manufacturing the first microcrystalline silicon oxycarbide layer, the second microcrystalline silicon oxycarbide layer, and the third microcrystalline silicon oxycarbide layer comprises: Forming a first microcrystalline silicon oxycarbide layer on the second intrinsic amorphous silicon layer by adopting Plasma Enhanced Chemical Vapor Deposition (PECVD) equipment, wherein the gas flow ratio of hydrogen to silane is 181-300, the gas flow ratio of phosphane to silane is 0.05-0.074, and the gas flow ratio of carbon dioxide to silane is 3.9-5; Continuously adopting the PECVD equipment, and regulating the gas flow rates of hydrogen, silane, phosphane and carbon dioxide gas to form a second microcrystalline silicon oxycarbide layer on the first microcrystalline silicon oxycarbide layer, wherein the gas flow rate ratio of hydrogen to silane is 121-180, the gas flow rate ratio of phosphane to silane is 0.075-0.11, and the gas flow rate ratio of carbon dioxide to silane is 1.7-3.8; And continuously adopting the PECVD equipment, and adjusting the gas flow rates of hydrogen, silane, phosphane and carbon dioxide gas to form a third microcrystalline silicon oxycarbide layer on the second microcrystalline silicon oxycarbide layer, wherein the gas flow rate ratio of the hydrogen to the silane is 25-120, the gas flow rate ratio of the phosphane to the silane is 0.12-0.15, and the gas flow rate ratio of the carbon dioxide to the silane is 0.5-1.6.

Description

Solar cell and preparation method thereof Technical Field The application relates to the technical field of solar cells, in particular to a solar cell and a preparation method thereof. Background In the photovoltaic field, the heterojunction solar cell (HJT) has the advantages of simple structure, low process temperature, good passivation effect, high open-circuit voltage, good temperature characteristic, double-sided power generation and the like, and is one of hot spot directions of the high-conversion-efficiency silicon-based solar cell. The conventional preparation method of the heterojunction solar cell deposits doped amorphous silicon (p/n-a-Si: H) on the surface of intrinsic amorphous silicon (i-a-Si: H), so that open circuit voltage can be effectively improved. However, the improper film thickness of p-a-Si: H can lead to parasitic absorption, resulting in reduced short-circuit current, and the amorphous structure is unfavorable for the migration of carriers (such as electrons and holes), thereby increasing the scattering and recombination loss of carriers in the transmission process, making the carriers not reach the electrode more efficiently, and reducing the current density and efficiency of the battery. In addition, a Schottky barrier exists between the n-a-Si H and the transparent conductive layer, the barrier height is greatly influenced by the effective doping concentration and the forbidden band width of the doped amorphous silicon layer, and the interface contact resistance is easily caused to be too high, so that the series resistance of the battery is increased and the filling factor is reduced. It should be noted that the foregoing is not necessarily prior art, and is not intended to limit the scope of the present application. Disclosure of Invention The application provides a solar cell and a preparation method thereof, which are used for solving or relieving the technical problems. The solar cell in the technical scheme is beneficial to migration of carriers and can improve current density and photoelectric conversion efficiency of the solar cell. In a first aspect, an embodiment of the present application provides a solar cell, including: A silicon substrate having a light incident surface and a light back surface arranged opposite to each other; the first intrinsic amorphous silicon layer and the first doped layer are positioned on the light incident surface and sequentially laminated along the direction far away from the silicon substrate, wherein the first doped layer comprises a nanocrystalline silicon oxide layer; The second doped layer comprises a first microcrystalline silicon oxycarbide layer, a second microcrystalline silicon oxycarbide layer and a third microcrystalline silicon oxycarbide layer which are sequentially stacked along the direction far away from the silicon substrate, wherein the carbon-oxygen ratio of the first microcrystalline silicon oxycarbide layer, the second microcrystalline silicon oxycarbide layer and the third microcrystalline silicon oxycarbide layer is sequentially decreased; Wherein the doping types of the first doping layer and the second doping layer are different. Optionally, the carbon-oxygen ratio of the first microcrystalline silicon oxycarbide layer is 0.6-0.8, the carbon-oxygen ratio of the second microcrystalline silicon oxycarbide layer is 0.4-0.6, and the carbon-oxygen ratio of the third microcrystalline silicon oxycarbide layer is 0.2-0.4. Optionally, the crystallization rate of the first microcrystalline silicon oxycarbide layer is 30% -40%, the crystallization rate of the second microcrystalline silicon oxycarbide layer is 15% -25%, and the crystallization rate of the third microcrystalline silicon oxycarbide layer is 35% -45%. Optionally, the first doped layer is a P-type doped layer, and the second doped layer is an N-type doped layer; The ratio of carbon, oxygen and phosphorus in the first microcrystalline silicon oxycarbide layer is (0.6-0.7): 1 (0.01-0.025), the ratio of carbon, oxygen and phosphorus in the second microcrystalline silicon oxycarbide layer is (0.45-0.55): 1 (0.025-0.045), and the ratio of carbon, oxygen and phosphorus in the third microcrystalline silicon oxycarbide layer is (0.2-0.3): 1 (0.045-0.06). Optionally, the thicknesses of the first microcrystalline silicon oxycarbide layer, the second microcrystalline silicon oxycarbide layer and the third microcrystalline silicon oxycarbide layer are respectively and independently 1-15nm. Optionally, the silicon-oxygen ratio of the nanocrystalline silicon oxide layer is 1.5-2, and/or The crystallization rate of the nanocrystalline silicon oxide layer is more than or equal to 25%. Optionally, the first doped layer is a P-type doped layer, and the second doped layer is an N-type doped layer; The boron doping concentration in the nanocrystalline silicon oxide layer is 1 multiplied by 10 19-1×1021atom/cm3. Optionally, the solar cell further includes: A first transparent con