Achieving 31.16 % efficiency in perovskite solar cells via synergistic Dion-Jacobson 2D-3D layer design

Abstract

Among environmental friendly energy sources solar energy is prominent one that can be harnessed via photovoltaic (PV) cells. The hybrid organic & inorganic perovskite solar cells (PSCs), have shown appealing PV performance. Halide-based perovskites (PVSK) offer several advantages, including low cost, high efficiency, and ease of fabrication. However, there are stability issues with these 3D perovskite materials. The solar device based on 2D PVSK materials are being used more and more in modern applications to address these problems. Ruddlesden-Popper (RP) & Dion-Jacobson (DJ) phases are the two main forms of 2D PVSK. These materials offer significantly greater stability compared to 3D perovskites, making them a promising alternative. In this study, we combine 2D and 3D perovskites to strengthen both reliability as well as efficiency of 3D PSCs. The present work explores the combined effect of DJ 2D-3D PVSK layers on device performance. The DJ 2D material used is PeDAMA4Pb5I16, while the 3D material is the lead-free, stable CsGeI3-xBrx (with x = 1). The optimized solar cell structure developed in this work consists of (Au/Cu2O/PeDAMA4Pb5I16/CsGeI3-xBrx/PCBM/FTO). A thorough analysis was performed on the impact of various ETLs and HTLs, as well as factors such as defect density (Nt), 2D-3D layer thickness, shallow acceptor density (NA), series (RS) and shunt resistances (RSh), and temperature variations. In the present work, PCE has significantly improved, reaching an amazing 31.16 %. Other noteworthy metrics include a JSC 22.55 mA.cm−2, FF 88.47 % and VOC 1.5617 V, all demonstrating exceptional performance. These results demonstrate the effectiveness of our approach in strengthening the efficiency and performance of DJ 2D-3D PSCs, highlighting their potential for future applications.