Novel Approach for Selective Emitter Formation and Front Side Metallization of Crystalline Silicon Solar Cells

Xu, Baomin¹ 

[1] Palo Alto Research Center, CA (United States)

关键词: ABLATION;    EFFICIENCY;    FABRICATION;    LASERS;    NITRIDES;    OPENINGS;    PERFORMANCE;    SCREENS;    SILICON SOLAR CELLS;    SILVER;    SOLAR CELLS;    TARGETS Crystalline Silicon;    Solar Cell;    Selective Emitter;    Front Side Metallization;    Las;   

DOI  :  10.2172/983937
RP-ID  :  DOE EE0000584
PID  :  OSTI ID: 983937
Others  :  TRN: US201106%%279

美国|英语

来源: SciTech Connect

【 摘 要 】

In this project we will explore the possibility of forming the front side metallization and selective emitter layer for the crystalline silicon solar cells through using selective laser ablation to create contact openings on the front surface and a screen printer to make connections with conductive paste. Using this novel approach we expect to reduce the specific contact resistance of the silver gridlines by about one order of magnitude compared to the state-of-art industrial crystalline silicon solar cells to below 1 m?????cm², and use lightly doped n+ emitter layer with sheet resistance of not smaller than 100 ??. This represents an enabling improvement on crystalline silicon solar cell performance and can increase the absolute efficiency of the solar cell by about 1%. In this scientific report we first present our result on the selective laser ablation of the nitride layer to make contact openings. Then we report our work on the solar cell fabrication by using the laser ablated contact openings with self-doping paste. Through various electrical property characterization and SIMS analysis, the factors limiting the cell performance have been discussed. While through this proof-of-concept project we could not reach the target on cell efficiency improvement, the process to fabricate 125mm full-sized silicon solar cells using laser ablation and self-doping paste has been developed, and a much better understanding of technical challenges has been achieved. Future direction to realize the potential of the new technology has been clearly defined.