Numerical simulations of perovskite thin-film solar cells using a CdS hole blocking layer

In this work, the numerical simulation of CH₃NH₃PbI₃ perovskite solar cells was undertaken using the scaps-1d solar cell capacitance simulator software. A perovskite solar cell was simulated for best efficiency by replacing the traditional compact TiO₂ layer with CdS (i.e., a hole-blocking layer) because CdS layers have been shown to possess a greater photostability than TiO₂ with continuous illumination of sunlight. With the view of optimizing the device fabrication of perovskite/CdS thin-film solar cell (TFSC) for maximum efficiency, the perovskite/CdS TFSC structure was optimized theoretically using scaps-1d, which is possible because the perovskite layer has the same configuration and an excitation type as CdTe, copper-indium-gallium-selenide, and other inorganic semiconductor solar cells. Solar cell performance is highly dependent on the layer parameters, and so the effect that absorber thickness, bulk defects, and interface defects have on the device performance was studied and the device was optimized. Further, the effect that atmospheric conditions have on device performance was studied by varying the temperature and illumination density, and the optimum performance was found. After these optimizations, the simulation results show that a perovskite thickness of 500 nm yields an efficiency of 23.83% with a high open-circuit voltage of 1.37 V. These results for this absorber thickness is in good agreement with reports of experimental results for this device.