Enhancing the solar cell efficiency with Azetidinium based Perovskites: An investigation for device optimization using DFT and SETFOS

Presently, organic cations that yield 3D perovskites with band gaps appropriate for PV applications comprise solely methylammonium (MA) and formamidinium (FA). However, these perovskites are prone to degradation at elevated temperatures and humid conditions. Multiple computational analyses have discovered azetidinium (AZ) as a promising third candidate for the synthesis of organic–inorganic perovskites. Exploring the operational mechanism and efficiency potential of perovskite solar cells (PSCs) based on AZ as cation requires a comprehensive investigation of both the material and device. In this study, DFT and SETFOS are combined to investigate PSCs based on perovskites with AZ cations. The structural, optoelectronic characteristics of the perovskites were computed and analysed based on DFT which identifies AZPbI₃, AZSnCl_3, AZSnBr₃ and AZSnI₃ as suitable perovskites within the AZ(Pb/Sn)X₃ (X = Cl, Br, I) family based on their favourable tolerance factors and calculated bandgaps of 1.87 eV, 1.67 eV, 1.1 eV and 0.8 eV, respectively. Further, numerical simulation for solar cells (SCs) is executed using SETFOS, with an optimized ETL and HTL for each of the perovskite absorbers. In addition, the devices are also tailored for their best thicknesses of transport layers and absorber layers. The optimized devices with architectures ITO/PCBM/AZPbI₃/CFTS/Ag, ITO/IGZO/AZSnCl₃/CuI/Ag, ITO/CeO₂/AZSnBr₃/CuI/Ag and ITO/CeO₂/AZSnI₃/PEDOT:PSS/Ag achieved PCEs of 19.48 %, 26.1 %, 16.5 %, and 12.01 % respectively. Along with, this study examines quantum efficiency (QE) and the impact of temperature on PV performance. Results of this comprehensive study lay the groundwork for a promising research path towards manufacturing high-efficiency, stable AZ based PSCs in due course.