Optical simulations and optimization of perovskite/CI(G)S tandem solar cells using the transfer matrix method

In this work we employ the transfer matrix method for the analysis of optical materials properties to simulate and optimize monolithic tandem solar cell devices based on CuIn$_{1−x}$Ga$_x$Se$_2$, CI(G)S, and perovskite (PVK) absorbers. By finding models that fit well the experimental data of the CI(G)S solar cell, the semitransparent perovskite solar cell (PSC) and the PVK/CI(G)S monolithic tandem solar cell, we were able to perform a detailed optical loss analysis that allowed us to determine sources of parasitic absorption. We found better substitute materials for the transport layers to increase the power conversion efficiency and, in case of semitransparent PSCs, sub-bandgap transmittance. Our results set guidelines for the monolithic PVK/CI(G)S tandem solar cells development, predicting an achievable efficiency of 30%.