CN-111755539-B - Solar cell and preparation method thereof

CN111755539BCN 111755539 BCN111755539 BCN 111755539BCN-111755539-B

Abstract

The embodiment of the invention discloses a solar cell and a preparation method thereof. The solar cell comprises a substrate, at least two subcells and a contact layer which are sequentially stacked from bottom to top, wherein a tunneling junction is arranged between every two adjacent subcells, the tunneling junction comprises an n-type first doping layer, an n-type second doping layer, a p-type first doping layer and a p-type second doping layer which are stacked, the n-type first doping layer is adjacent to the n-type second doping layer, the p-type first doping layer is adjacent to the p-type second doping layer, the n-type first doping layer is adjacent to the p-type first doping layer, the doping concentration of n-type ions of the n-type first doping layer is higher than the doping concentration of the n-type second doping layer, and the doping concentration of p-type ions of the p-type first doping layer is higher than the doping concentration of the p-type second doping layer. The preparation method is used for preparing the solar cell. The solar cell and the preparation method provided by the embodiment of the invention improve the photoelectric conversion efficiency of the solar cell.

Inventors

HUANG WENYANG

Assignees

紫石能源有限公司
东泰高科装备科技有限公司

Dates

Publication Date: 20260421
Application Date: 20190329
Priority Date: 20190329

Claims (4)

1. The solar cell comprises a substrate, at least two sub-cells and a contact layer which are sequentially stacked from bottom to top, wherein a tunneling junction is arranged between every two adjacent sub-cells, and the solar cell is characterized in that the tunneling junction comprises: The device comprises an n-type first doping layer, an n-type second doping layer, a p-type first doping layer and a p-type second doping layer which are stacked, wherein the n-type first doping layer is adjacent to the n-type second doping layer, the p-type first doping layer is adjacent to the p-type second doping layer, and the n-type first doping layer is adjacent to the p-type first doping layer; The thickness of the n-type second doping layer is 2-5 nm, the thickness of the n-type first doping layer is 5-10 nm, the thickness of the p-type second doping layer is 2-5 nm, and the thickness of the p-type first doping layer is 5-10 nm; The n-type second doped layer is an n-type Al x In (1-x) P layer, the n-type first doped layer is an n-type Al y In (1-y) P layer, the P-type first doped layer is a P-type Al z In (1-z) P layer, and the P-type second doped layer is a P-type Al w In (1-w) P layer, wherein 0.25< x <0.55,0.25< y <0.55,0.25< z <0.55,0.25< w <0.55; The doping concentration of n-type ions of the n-type second doping layer is 5E 17-5E 18/cm 3 , the doping concentration of n-type ions of the n-type first doping layer is 2E 19-2E 20/cm 3 , the doping concentration of p-type ions of the p-type second doping layer is 5E 17-5E 18/cm 3 , and the doping concentration of p-type ions of the p-type first doping layer is 2E 19-2E 20/cm 3 ; Or an n-type third doping layer, an n-type fourth doping layer and a p-type fifth doping layer which are arranged in a stacked manner, wherein the n-type third doping layer is adjacent to the n-type fourth doping layer, and the n-type fourth doping layer is adjacent to the p-type fifth doping layer; The thickness of the n-type third doping layer is 2-5nm, the thickness of the n-type fourth doping layer is 5-10 nm, and the thickness of the P-type fifth doping layer is 2-5nm, wherein the n-type third doping layer is an n-type Al a In (1-a) P layer, the n-type fourth doping layer is an n-type Al b In (1-b) P layer, and the P-type fifth doping layer is a P-type Al c In (1-c) P layer, wherein 0.25< a <0.55,0.25< b <0.55,0.25< c <0.55; The doping concentration of n-type ions of the n-type third doping layer is 5E 17-5E 18/cm 3 , the doping concentration of n-type ions of the n-type fourth doping layer is 2E 19-2E 20/cm 3 , and the doping concentration of p-type ions of the p-type fifth doping layer is 5E 17-5E 18/cm 3 ; Or a p-type third doping layer, a p-type fourth doping layer and an n-type fifth doping layer which are arranged in a stacked manner, wherein the p-type third doping layer is adjacent to the p-type fourth doping layer, and the p-type fourth doping layer is adjacent to the n-type fifth doping layer; the thickness of the p-type third doping layer is 2-5 nm, the thickness of the p-type fourth doping layer is 5-10 nm, and the thickness of the n-type fifth doping layer is 2-5 nm; The P-type third doping layer is a P-type Al d In (1-d) P layer, the P-type fourth doping layer is a P-type Al f In (1-f) P layer, and the n-type fifth doping layer is an n-type Al g In (1-g) P layer, wherein 0.25< d <0.55,0.25< f <0.55,0.25< g <0.55; The doping concentration of p-type ions of the p-type third doping layer is 5E 17-5E 18/cm 3 , the doping concentration of p-type ions of the p-type fourth doping layer is 2E 19-2E 20/cm 3 , and the doping concentration of n-type ions of the n-type fifth doping layer is 5E 17-5E 18/cm 3 .
2. A method of fabricating a solar cell according to claim 1, comprising the steps of: when the substrate is a p-type substrate, an n-type second doped layer, an n-type first doped layer, a p-type first doped layer and a p-type second doped layer are sequentially grown from bottom to top, wherein the doping concentration of n-type ions of the n-type first doped layer is higher than that of n-type ions of the n-type second doped layer, and the doping concentration of p-type ions of the p-type first doped layer is higher than that of p-type ions of the p-type second doped layer; or when the substrate is a p-type substrate, an n-type third doping layer, an n-type fourth doping layer and a p-type fifth doping layer are sequentially grown from bottom to top, wherein the doping concentration of n-type ions of the n-type fourth doping layer is higher than that of n-type ions of the n-type third doping layer; Or when the substrate is a p-type substrate, the n-type fifth doped layer, the p-type fourth doped layer and the p-type third doped layer are sequentially grown from bottom to top, wherein the doping concentration of p-type ions of the p-type fourth doped layer is higher than that of n-type ions of the p-type third doped layer; Or when the substrate is an n-type substrate, the p-type second doped layer, the p-type first doped layer, the n-type first doped layer and the n-type second doped layer are sequentially grown from bottom to top, wherein the doping concentration of n-type ions of the n-type first doped layer is higher than that of n-type ions of the n-type second doped layer, and the doping concentration of n-type ions of the n-type first doped layer is higher than that of n-type ions of the n-type second doped layer; Or when the substrate is an n-type substrate, the p-type third doping layer, the p-type fourth doping layer and the n-type fifth doping layer are sequentially grown from bottom to top, wherein the doping concentration of n-type ions of the n-type fourth doping layer is higher than that of n-type ions of the n-type third doping layer; Or when the substrate is an n-type substrate, the p-type fifth doped layer, the n-type fourth doped layer and the n-type third doped layer are sequentially grown from bottom to top, wherein the doping concentration of n-type ions of the n-type fourth doped layer is higher than that of n-type ions of the n-type third doped layer.
3. The preparation method according to claim 2, wherein the growth temperature conditions of the n-type first doping layer and the p-type first doping layer are 500-650 ℃, the growth temperature conditions of the n-type second doping layer and the p-type second doping layer are 700-830 ℃, the growth temperature conditions of the n-type third doping layer and the p-type fifth doping layer are 500-650 ℃, the growth temperature conditions of the n-type fourth doping layer are 700-830 ℃, or the growth temperature conditions of the p-type third doping layer and the n-type fifth doping layer are 500-650 ℃, and the growth temperature conditions of the p-type fourth doping layer are 700-830 ℃.
4. The method according to claim 2 or 3, wherein the growth rate of the n-type second doped layer is 0.5-2 nm/s, the growth rate of the n-type first doped layer is 0.2-1 nm/s, the growth rate of the p-type second doped layer is 0.5-2 nm/s, or the growth rate of the n-type fourth doped layer is 0.5-2 nm/s, the growth rate of the n-type third doped layer is 0.2-1 nm/s, the growth rate of the p-type fifth doped layer is 0.2-1 nm/s, or the growth rate of the p-type fourth doped layer is 0.5-2 nm/s, the growth rate of the p-type third doped layer is 0.2-1 nm/s, and the growth rate of the n-type fifth doped layer is 0.2-1 nm/s.

Description

Solar cell and preparation method thereof Technical Field The embodiment of the invention relates to the technical field of semiconductors, in particular to a solar cell and a preparation method thereof. Background Gallium arsenide solar cells have good spectral response and are generally applied to the fields of aerospace, concentrating photovoltaic power stations and the like. The gallium arsenide solar cell is formed by connecting a plurality of sub-cells in series, each sub-cell is connected in series by a tunneling junction, the energy bands of the sub-cells are sequentially raised from bottom to top, and the sub-cells respectively absorb light with different wavelengths, so that full spectrum absorption is realized. However, most of the tunneling junctions of the existing gallium arsenide solar cells are made of gallium arsenide (GaAs) or aluminum gallium arsenide (AlGaAs) materials, the light transmittance of the tunneling junctions is not ideal, light which is not absorbed by the upper sub-cells is transmitted to the lower sub-cells, and the photoelectric conversion efficiency is low. Therefore, how to provide a solar cell capable of using a tunneling junction with good light transmittance so as to improve the photoelectric conversion efficiency of the solar cell is an important issue to be solved in the industry. Disclosure of Invention Aiming at the defects in the prior art, the embodiment of the invention provides a solar cell and a preparation method thereof. In one aspect, an embodiment of the present invention provides a solar cell, including a substrate, at least two subcells, and a contact layer sequentially stacked from bottom to top, where a tunneling junction is disposed between two adjacent subcells, where the tunneling junction includes: The device comprises an n-type first doping layer, an n-type second doping layer, a p-type first doping layer and a p-type second doping layer which are stacked, wherein the n-type first doping layer is adjacent to the n-type second doping layer, the p-type first doping layer is adjacent to the p-type second doping layer, and the n-type first doping layer is adjacent to the p-type first doping layer; Or an n-type third doping layer, an n-type fourth doping layer and a p-type fifth doping layer which are arranged in a stacked manner, wherein the n-type third doping layer is adjacent to the n-type fourth doping layer, and the n-type fourth doping layer is adjacent to the p-type fifth doping layer; Or a p-type third doping layer, a p-type fourth doping layer and an n-type fifth doping layer which are arranged in a stacked manner, wherein the p-type third doping layer is adjacent to the p-type fourth doping layer, the p-type fourth doping layer is adjacent to the n-type fifth doping layer, and the doping concentration of p-type ions of the p-type fourth doping layer is higher than that of p-type ions of the p-type third doping layer. In another aspect, an embodiment of the present invention provides a method for preparing a solar cell according to the above embodiment, including the following steps of: when the substrate is a p-type substrate, an n-type second doped layer, an n-type first doped layer, a p-type first doped layer and a p-type second doped layer are sequentially grown from bottom to top, wherein the doping concentration of n-type ions of the n-type first doped layer is higher than that of n-type ions of the n-type second doped layer, and the doping concentration of p-type ions of the p-type first doped layer is higher than that of p-type ions of the p-type second doped layer; or when the substrate is a p-type substrate, an n-type third doping layer, an n-type fourth doping layer and a p-type fifth doping layer are sequentially grown from bottom to top, wherein the doping concentration of n-type ions of the n-type fourth doping layer is higher than that of n-type ions of the n-type third doping layer; Or when the substrate is a p-type substrate, the n-type fifth doped layer, the p-type fourth doped layer and the p-type third doped layer are sequentially grown from bottom to top, wherein the doping concentration of p-type ions of the p-type fourth doped layer is higher than that of n-type ions of the p-type third doped layer; Or when the substrate is an n-type substrate, the p-type second doped layer, the p-type first doped layer, the n-type first doped layer and the n-type second doped layer are sequentially grown from bottom to top, wherein the doping concentration of n-type ions of the n-type first doped layer is higher than that of n-type ions of the n-type second doped layer, and the doping concentration of n-type ions of the n-type first doped layer is higher than that of n-type ions of the n-type second doped layer; Or when the substrate is an n-type substrate, the p-type third doping layer, the p-type fourth doping layer and the n-type fifth doping layer are sequentially grown from bottom to top, wherein the doping concentration of n-typ