Optical Simulation of Planar CH3NH3PbI3 Perovskite Solar Cells

Abstract

In this work, optical simulation results of planar CH3NH3PbI3 solar cells using a MATLAB script developed by McGehee’s group (Stanford University) will be presented. The device structure is FTO/HEL/AL/ETL/LiF/Al, where HEL is a hole-extraction layer, AL is an active layer (CH3NH3PbI3), and EEL is an electron-extraction layer. This MATLAB script uses the transfer matrix method, where transmission and reflection are calculated for each interface in the stack as well as attenuation in each layer. The wavelength-dependent optical constants (n and k) of each layer were measured by spectroscopic ellipsometry (SE). The exciton generation rates within the active layer were calculated and with an assumption that the Internal Quantum Efficiency (IQE) equals 100% at all wavelengths, the predicted short-circuit currents (JSC) were also estimated. These results show a good agreement with the experimental values of JSC measured on real devices.