Electronic and optical properties of all-inorganic TiX3 transition metal halide nanowires

Transition metal halides are promising for use in photovoltaics and optoelectronics. This research systematically investigated the composition-dependent electronic and optical properties of all-inorganic TiX₃ (X = Cl/Br/I) transition metal halide nanowires using first-principles density functional theory (DFT) and time-dependent DFT calculations. The findings emphasize the significant impact of the specific halide type on the electronic and optical characteristics of TiX₃ nanowires. Particularly, the type of halide significantly influences the electronic states near the Fermi level and the infrared photoabsorption properties. An important discovery is the exceptional photoabsorption strength observed in the TiCl₃ nanowire, reaching an impressive value of 26000 cm⁻¹. The study also offers insights into exciton generation, aided by Transition Contribution Maps. Apart from its theoretical implications, we expect that the insights gained from this research will contribute to the advancement of active optical devices utilizing all-inorganic halide perovskites.