Optimization and performance analysis of high dielectric bulk heterojunction organic solar cell through the layers configuration

Abstract Fossil fuel reserves are rapidly depleting, while global energy demand continues to rise due to urbanization. Therefore, renewable energy sources are essential to meet future energy needs. Organic solar cells (OSCs) have emerged as promising next-generation photovoltaic technologies owing to their flexibility, lightweight nature, and compatibility with low-cost solution processing. However, achieving commercially viable efficiencies requires strategic optimization of both device architecture and electronic parameters. In this study, a comprehensive simulation based investigation was conducted using the SCAPS-1D to analyze the impact of key physical and electronic factors on OSC performance. The device was simulated using an inverted configuration such as FTO/PFN-Br/PBDB-T-2F:BTP-4F/CFTS/Pt, where FTO serves as the front contact, PFN-Br act as the electron transport layer (ETL), PBDB-T-2F:BTP-4F as the bulk heterojunction (BHJ) active layer, Cu 2 FeSnS 4 (CFTS) serves as the hole transport layer (HTL), while platinum is employed as the back contact. Parameters such as the active layer thickness, defect density, band gap tuning, electron affinity, charge transport layer doping, and back contact work function were optimized. The resulting device achieved an open circuit voltage (Voc) of 1.057 V, a short circuit current density (Jsc) of 21.833 mA cm −2 , a fill factor (FF) of 62.28%, and a power conversion efficiency (PCE) of 14.38%. The key novelty of this work lies in the employing CFTS as a non-toxic, earth-abundant HTL, which offers favorable energy level alignment with the PBDB-T-2F:BTP-4F active layer, enabling efficient hole extraction and reducing interfacial energy barriers. These findings present a sustainable and efficient design strategy for high-performance inverted OSCs, contributing to the advancement of scalable renewable energy technologies.