Perovskite Solar Cells with Dual Light Absorber Layers for Performance Efficiency Exceeding 30%

The present work represents a comparative modeling and performance optimization of three device configurations: ITO/ZnO/Cs2BiAgI6/Spiro-OMeTAD/Au, ITO/ZnO/CIGS/Spiro-OMeTAD/Au, and ITO/ZnO/Cs2BiAgI6/CIGS/Spiro-OMeTAD/Au. The concern of low light absorption by materials such as Cs2BiAgI6 and CIGS limits its application as a light absorber in photovoltaic devices. Nevertheless, the light absorption by the device can be enhanced by the inclusion of a second light active layer composed of the graded active layer of both Cs2BiAgI6/CIGS, which effectively boosts the efficiency of the device configuration. In this study, SCAPS-1D software was employed for analyzing the proposed solar cell models. The optimized output parameters achieved include JSC of 31.89 mA/cm2, VOC of 1.108 V, FF of 85.01%, and PCE of 30.10%, which approaches the Shockley-Queisser limit.