Coupled process and device modeling of Cu(In,Ga)Se2 solar cells

Point defects directly impact solar cell device performance by limiting the carrier lifetime. In this work, density functional theory calculations are first conducted to determine the formation energy and diffusion energy barriers of dominant defects in Cu(In,Ga)Se2. Next, continuum models are developed to model the redistribution of defects during cooling and annealing processes. The calculated defect profiles as well as the corresponding capture cross sections and trap energy levels are implemented into device simulation via Shockley-Read-Hall (SRH) recombination models to calculate carrier lifetime and device performance. In that way, a predictive TCAD model is built to optimize the composition and performance of Cu(In,Ga)Se2 solar cells.