High Performance of Heterojunction Perovskite Solar Cells with Mixed Halide FAPbI₃/FAPbBr₂I

The main goal of this research is to enhance the performance of perovskite solar cells (PSCs) by investigating single perovskite solar cells (SPSCs) and double perovskite solar cells (DPSCs). Despite limited research time, organic- inorganic SPSCs and DPSCs have achieved remarkable efficiency. SPSCs and DPSCs based on formamidinium (FAPb(Ii-<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</inf>Br<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</inf>).i) have emerged as promising candidates for organic-inorganic PSCs. We used the semiconductor design software Silvaco Tcad to simulate and analyze the three devices as follows: FTO / TiO<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> / FAPbI<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</inf> / SpiroOMeTAD /Au, FTO / TiO<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> / FAPbBr<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf>I / SpiroOMeTAD / Au, and FTO / TiO<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> / FAPbI<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</inf> / FAPbBr<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf>I / Spiro-OmeTAD / Au. The DPSC exhibits higher performance compared to the SPSCs. Moreover, by optimizing the layer thicknesses of the two perovskites, the power conversion efficiency (PCE) significantly improves, reaching 37.44 % with thicknesses of 350 nm and 750 nm for the FAPbI<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</inf> and FAPbBr2I perovskite layers, respectively. The enhanced performance can be attributed to the thicker FAPbBr2I layer, which facilitates more effective capture of photons at longer wavelengths. This increased light harvesting capacity results in superior overall photogeneration, leading to elevated photocurrent and ultimately greater PCE. The findings demonstrate how double perovskite solar cells offer significant advantages for developing higher performing photovoltaic devices.