TCAD Calibration for Cu2ZnSnS4 Solar Cell Simulation

We present a TCAD simulation deck for Cu2ZnSnS4 (CZTS) solar cells that is calibrated to data from the best reported experimental device structure: the wherewithal for future predictive device modeling. The calibration is performed by matching the experimental external quantum efficiency (EQE) and current density vs. voltage (J-V) characteristics with those obtained from combined optical and electrical simulations. We find that using theoretically calculated extinction coefficient (k) values in the simulation leads to large discrepancy with experiment; on the other hand, experimentally measured k-values for bulk CZTS need only modest modification (at near-bandgap) in order to be able to fit the EQE data for the device-structured CZTS that we have here.