Perovskite Solar Cells: Optoelectronic Simulation and Optimization

To realize reliably high efficiency of perovskite solar cells (PSCs), material synthesis, interface manipulation, and device realization have been widely studied. Nevertheless, deeply understanding the fundamental optics and physics which regulate the multi-domain optoelectronic responses is crucial. Here, the authors present an optoelectronic study of PSCs under various configurations. It combines electromagnetic response and carrier electrodynamics inside PSCs so that the microscopic response in frequency/spatial domains and the device output can be obtained. The effects of perovskite doping type/concentration/thickness and doping concentrations of electron (hole) transport layer (i.e., ETL [HTL]) on the optoelectronic response of the complete, free-HTL, and free-ETL PSCs are studied. The energy diagrams addressing the band bending, the built-in electrical field addressing the carrier separation, and the surface/bulk recombination addressing the current losses are analyzed. It is found that the doping type of perovskite greatly affects the cell performance, for example, for ETL-side illumination, p-perovskite enables higher efficiency than n-doping due to a much reduced bulk recombination. Achieving good agreements with existing experiments, the model is used for the design of PSCs. It shows that the photoconversion efficiencies of complete, free-HTL, and free-ETL PSCs can be enhanced from 16.6%, 10.7%, and 13.3% to 19.0%, 15.9%, and 18.5%, respectively.