A comprehensive DFT + U investigation of electrical, optical, and structural properties of doped CsSnCl3 Perovskite: Unveiling optoelectronic potential

In the realm of advanced electrical and photovoltaic applications, inorganic metal halide perovskites (MHP) have captured attention. However, CsSnCl3, a notable member of MHPs, displays limited electro-optical potential due to its substantial bandgap and poor visible spectrum absorbance, which impedes its ability to achieve ideal optoelectronic efficiency. In this study, we used density functional theory (DFT) and the DFT + U technique to compute and investigate the structural, elastic, electrical, and optical properties of pure CsSnCl3 and its doped phases containing Ti, V, Cr, and Mn with different concentrations. Notably, this study represents the first utilization of DFT + U to simultaneously assess the band structure of both pure and doped CsSnCl3. Through meticulous alignment with experimental data and the derivation of a suitable Hubbard U correction value (6.5), our analysis reveals a refined band structure for pristine CsSnCl3. Critically, our research transcends conventional bandgap understanding, unlocking a profound connection between bandgap modulation and enhanced optoelectronic efficiency. Specifically, our systematic exploration uncovers a noteworthy enhancement in performance for various optoelectronic applications upon doping with V, Ti, Cr, and Mn, substantiating the practicality of our approach. Investigations into mechanical stability reveal that all doped samples exhibit a remarkable ductile nature, rendering them well-suited for thin-film solar cell production and other applications demanding stability and flexibility. By bridging the gap between theory and application, our study empowers researchers and industry professionals with actionable insights for selecting the most suitable doped compositions of CsSnCl3, ushering in an era of highly efficient and environmentally sustainable optoelectronic technologies.