Fabrication of Zn‐doped Cu(In,Ga)Se2 thin film solar cells prepared by Zn diffusion from the gas phase using dimethylzinc

Abstract

AbstractCu(In,Ga)Se2 (CIGS) solar cells were fabricated by thermal diffusion of Zn into p ‐type CIGS films using dimethylzinc [(CH3)2Zn: DMZn] vapor, in order to form CIGS pn ‐homojunction. This method requires no additional processing equipment, because diffusion can be carried out subsequent to the CIGS growth. The average conversion efficiency of the CIGS solar cells consisting of n ‐type MgZnO transparent conducting oxide (TCO) film and n ‐CIGS:Zn/p ‐CIGS structure (4%) was improved by a factor of two in comparison with the case for undoped CIGS absorbing layer (2%). The appropriate flow time of DMZn was 3 s, from which the diffusion depth is estimated as about 150 nm. The method is highly advantageous for development of low‐cost solar modules. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)