两步法制备的CuInGaSe_2薄膜中Ga的富集现象  

Segregation of Ga in CuInGaSe_2 Films Grown by Magnetron Sputtering and Selenization

作　　者：李春雷[1] 庄大明[1] 张弓[1] 刘江[1] 宋军[1] 

机构地区：[1]清华大学机械工程系,北京100084

出　　处：《真空科学与技术学报》2011年第5期641-645,共5页Chinese Journal of Vacuum Science and Technology

基　　金：国家863项目(2007AA05Z461)

摘　　要：采用预制膜硒化两步法制备CIGSe薄膜,采用X射线衍射方法分析薄膜的结构,采用荧光光谱分析和俄歇电子能谱分析方法检测分析薄膜的成分。研究结果表明CIGSe薄膜中Ga元素以置换原子的形式存在于CuInSe2相中,并且Ga具有背电极富集现象。富集现象弱化了Ga元素对禁带宽度的提高作用,并且由于薄膜背电极侧Ga含量过高导致背电极处缺陷浓度增加,从而降低了CIGSe薄膜的质量。结合Zhang等对CuInSe2和CuGaSe2中缺陷对生成能的理论计算,本文认为较高的2VCu-GaCu缺陷对形成能造成了Ga元素的背电极富集现象。The CuInGaSe2 films were deposited on glass substrates in two-steps：growth of the CuInGa films by magnetron co-sputtering of CuIn and CuGa targets,followed by a selenization.The impacts of the film growth conditions on the microstructures and depth profiles of the CuInGaSe2 films were characterized with X-ray diffraction,X-ray fluorescence,and Auger electron spectroscopy.The results show that the non-uniform,surface segregation of Ga inversely affects the efficiency of the solar cells.For example,the Ga segregation decreases the donor levels density in the band gap of the absorber,and increases the defect density at the interface of the film and the substrate.The possible mechanism（s） of the Ga segregation was also tentatively discussed.

关 键 词：太阳能电池 铜铟镓硒 两步法 预制膜硒化 背电极富集 

分 类 号：TK513[动力工程及工程热物理—热能工程]