Numerical Simulation of an Inverted Perovskite Solar Cell Using a SiOx Layer as Down-Conversion Energy Material to Improve Efficiency and Stability

Inverted perovskite solar cells (PSCs) have gained much attention due to their low hysteresis effect, easy fabrication, and good stability. In this research, an inverted perovskite solar cell ITO/PEDOT:PSS/CH₃NH₃PbI₃/PCBM/Ag structure was simulated and optimized using SCAPS-1D version 3.3.10 software. The influence on the device of parameters, including perovskite thickness, total defect density, series and shunt resistances, and operating temperature, are discussed and analyzed. With optimized parameters, the efficiency increased from 13.47% to 18.33%. Then, a new $\mathrm{Si}{\mathrm{O}}_{\mathrm{x}}$/ITO/PEDOT:PSS/CH₃NH₃PbI₃/PCBM/Ag device was proposed which includes a silicon-rich oxide ($\mathrm{Si}{\mathrm{O}}_{\mathrm{x}}$) layer. This material was used as the down-conversion energy material, which converts high-energy photons (ultraviolet UV light) into low-energy photons (visible light), improving the stability and absorption of the device. Finally, with $\mathrm{Si}{\mathrm{O}}_{\mathrm{x}}$, we obtained an efficiency of 22.46% in the simulation. Therefore, the device with the $\mathrm{Si}{\mathrm{O}}_{\mathrm{x}}$ layer is the most suitable as it has better values for current density–voltage output and quantum efficiency than the device without $\mathrm{Si}{\mathrm{O}}_{\mathrm{x}}$.