Investigation of ZnO/CdS/CuInxGa1−xSe2 interface reaction by using hot-stage TEM

Abstract A section of complete solar cell device consisting of Ag/Al:ZnO/i-ZnO/Cu(In,Ga)Se 2 /Mo/glass was in situ annealed inside of TEM column and the interfacial variation was directly investigated in real-time. A pore structure was formed in CdS layer adjacent to CIGS after annealing at 200 °C, and the compositional mapping obtained after 300 °C annealing showed a heavy diffusion of Ga into ZnO layer. Therefore, Ga-assisted Cd diffusion is suggested to be responsible for the pore evolution, which is highly relevant to the device degradation after high temperature annealing.