Enhancing P3HT-Based Organic Solar Cells via CsGeI₂Br Perovskite Interlayer Integration

Abstract

In this study, the impact of incorporating an intrinsic perovskite layer (CsGeI₂Br) on the performance of P3HT-based organic solar cells was investigated using numerical simulation. A multi-layer device structure (PCBM/C60/P3HT/Cu₂O) was modeled with and without the insertion of the perovskite layer between the C60 and P3HT layers. Various physical parameters were optimized, including the perovskite thickness, bandgap, electron affinity, defect density, and effective density of states. The results indicate that the inclusion of the perovskite layer enhances photon absorption, facilitates charge carrier separation, and reduces recombination losses-resulting in a significant improvement in power conversion efficiency (PCE). The optimized structure achieved a PCE of 33.46%, compared to 26.9% for the device without the perovskite layer. These findings highlight the potential of lead-free perovskite materials in advancing high-performance, environmentally sustainable organic photovoltaics.