US 12,243,952 B2
Double-sided passivated contact cell and preparation method thereof
Changrui Ren, Suzhou (CN); Songbo Yang, Henan (CN); Jianwen Dong, Suzhou (CN); and Liming Fu, Zhejiang (CN)
Assigned to CHANGZHOU SHICHUANG ENERGY CO., LTD, Jiangsu (CN)
Appl. No. 18/711,116
Filed by CHANGZHOU SHICHUANG ENERGY CO., LTD, Suzhou (CN)
PCT Filed Sep. 15, 2022, PCT No. PCT/CN2022/118909
§ 371(c)(1), (2) Date May 17, 2024,
PCT Pub. No. WO2023/087879, PCT Pub. Date May 25, 2023.
Claims priority of application No. 202111374547.4 (CN), filed on Nov. 19, 2021.
Prior Publication US 2025/0015221 A1, Jan. 9, 2025
Int. Cl. H01L 31/18 (2006.01); H01L 31/0216 (2014.01); H01L 31/0236 (2006.01); H01L 31/0288 (2006.01); H01L 31/0368 (2006.01)
CPC H01L 31/182 (2013.01) [H01L 31/02167 (2013.01); H01L 31/02366 (2013.01); H01L 31/0288 (2013.01); H01L 31/03682 (2013.01)] 6 Claims
 
1. A preparation method of a double-sided passivated contact cell, comprising the following steps: after surface texturing on a silicon wafer, preparing a tunnel layer at each of a front side and a rear side of the silicon wafer; then preparing a carbon doped polysilicon layer at each of the front side and the rear side of the silicon wafer by plasma enhanced chemical vapor deposition (PECVD) or low pressure chemical vapor deposition (LPCVD) using methane as a carbon source for carbon doping, wherein a content of carbon doped in the carbon doped polysilicon layer is 1% to 5%; then performing boron doping on one of the carbon doped polysilicon layer at the front side and the carbon doped polysilicon layer at the rear side, and performing phosphorous doping on the other of the carbon doped polysilicon layer at the front side and the carbon doped polysilicon layer at the rear side; then preparing a passivation layer at each of the front side and the rear side of the silicon wafer; and then printing an electrode at each of the front side and the rear side of the silicon wafer, wherein
the methane is used as the carbon source to increase a content of H in a passivation interface to improve a passivation effect; and
the carbon doping is performed to increase a band gap of the polysilicon layer to obtain a wide-band gap modified polysilicon, and the wide-band gap modified polysilicon is used as a passivation material at the front side and the rear side to reduce a loss from an infrared parasitic absorption, increase a cell current, and improve a solar cell efficiency.