Wide-band-gap Cu(In,Ga)S-2 solar cells with the junction prepared on the rear surface of the three-stage Cu-deficient absorber films

摘要

Cu(In,Ga)S-2 (CIGS) solar cells were prepared from Cu-deficient absorber films using a lift-off process and then compared with CIGS solar cells prepared without using the lift-off process. The lift-off was achieved through sacrificial molybdenum layers and optimized by different modifications of the latter. We report on the properties of the detached surfaces in terms of their dependence on the composition of the films and compare them to those of the original upper surfaces. This comparison suggests the advantageous properties of the detached surfaces in terms of composition, absence of Cu-deficient phases, and effective doping. (C) 2015 The Japan Society of Applied Physics