Exploring the Physical, Electrical and Optical Properties of Cs₂LiInBr₆ Perovskite: An Extensive study Utilizing DFT Based GGA-PBE and HSE06 Functionals

We performed a thorough investigation of the structural, mechanical, electrical, and optical characteristics of the lead-free perovskite Cs₂LiInBr₆ by employing the Density Functional Theory (DFT) methods. Our analysis included the use of GGA-PBE and HSE06 functionals. Our results validate that Cs₂LiInBr₆ forms a cubic Fm̅3m space group with a lattice constant of 11.09 Å, which is consistent with earlier theoretical and experimental investigations. The material possesses a direct bandgap at 1.50 eV and 2.34 eV, calculated by GGA-PBE and HSE06 methods respectively. This shows that the material is suitable for solar cell and optoelectronic applications. Finally, the substantial UV and visible region absorption (90,455 cm⁻¹ with GGA-PBE) observed for Cs₂LiInBr₆ makes it an attractive material for solar applications. The moderate level of compressibility and ductile nature of the mechanical properties further validate the structural integrity of Cs₂LiInBr₆. The details of the physical properties including mechanical, electrical, optical, and structural features suggest that Cs₂LiInBr₆ is a promising material for photovoltaic as well as optoelectronic applications.