DFT Insights into the Pressure-induced Ultraviolet to Visible Band Gap Engineering of TlMgF3 Cubic Halide Perovskites for Optoelectronic Applications

The current study utilizes first-principle calculation in order to investigate the geometrical, electrical, mechanical, and optical characteristics of TlMgF3 cubic halide perovskites under the effect of hydrostatic pressure. The interatomic distance is significantly reduced, causing a substantial decrease in the unit cell volume and lattice constant of TlMgF3 perovskite. The electronic energy band gap undergoes a transition from the UV to the visible region in response to the hydrostatic pressure, thereby allowing electron transport from the valence band to the conduction band. This causes some interesting observations in the electronic and optical characteristics of many optoelectronic devices. Additionally, at approximately 500 GPa pressure, the direct band gap is tuned from 4.275 eV to 1.66 eV, making the material suitable for use in solar cell applications. Deep optical analysis has recommended the utilization of TlMgF3 in numerous other applications, including microelectronics, QLED (quantum dot light-emitting diode), OLED (organic light-emitting diode), solar heat reduction materials, and surgical instruments. When external hydrostatic pressure is applied, the mechanical properties of the material are also substantially altered, resulting in increased flexibility and anisotropy.