Enhancing the efficiency of PM6:Y6 bulk-heterojunction organic solar cells through SCAPS simulation optimization

Organic solar cell (OSC) is becoming a point of attraction in the solar cell industry due to their benefits, such as light weight, flexibility, low cost, semi-transparency, and easy fabricating methods. By replacing fullerene with non-fullerene acceptors like Y6, ITIC, PCBM, and ICBA, the power conversion efficiency (PCE) of OSCs has surpassed the 15% benchmark. Here, the proposed OSC structure includes an ITO front contact electrode, SnO2 electron transport layer (ETL), PM6: Y6 active layer, Cu2O hole transport layer (HTL), and Ag back contact electrode. Systematic numerical simulation of the above proposed OSC has been performed using a solar cell capacitance simulator (SCAPS)-1D (Version 3.3.09). The device improvement analysis has been carried out in steps by analyzing the ETL-HTL effect, selecting the optimum thickness of the active layer, and the optimum value of defect density. In the first step, a PCE of 24.60% was achieved, followed by an improvement to 27.55% with the optimized defect density value. The best PCE of 27.74% was achieved in the third step with an optimized active layer thickness, leading to high fill factor (80.56%), open-circuit voltage (0.9461 V), and short-circuit current density (36.188 mA/cm2). These simulated results promote an in-depth understanding of the optical and electronic properties of PM6:Y6 blend-based OSC and show the potential of NFA-BHJ OSCs as promising candidates for solar cells in the near future.