Computational Study of the Structural, Mechanical and Optoelectronic Properties of Metal-halide Perovskites for Hybrid Energy Storage Applications

Abstract

Metal-halide perovskites (MHPs) are investigated in industrial applications due to optoelectronics and energy storage properties. In this study, the effects of hydrostatic pressure on the structural, electronic, elastic and optical properties of CsPbM₃ (M = F, Cl, Br, and I) are studied through using theoretical calculations based on the FP-LAPW method in Materials Studio, with GGA-PBE and LDA-CAPZ parameterizations. The exchange-correlation energies are calculated with GGA-PBE and LDA-CAPZ parameterizations. Results indicate that CsPbCl₃ with GGA-PBE exhibits the highest mechanical stability with a bulk modulus of 24.67 GPa, B/G ratio of 2.49, and positive elastic constants. CsPbF₃ (LDA-CAPZ) is the hardest (9.73 GPa) but mechanically unstable under pressure. Moreover, the CsPbM₃ exhibits a vertical-electron transition as well as semiconductor with a direct band gap at R- symmetry point as the band gap decreases between CsPbF₃ (2.629 eV PBE, 2.498 eV LDA) to CsPbI 3 (1.303 eV PBE, 1.280 eV LDA) respectively. A red shift in absorption and higher static dielectric constant occurs with increasing halide atomic radius. CsPbI₃ shows strong infrared and visible absorption, ideal for solar cells, while CsPbCl₃ and CsPbBr₃ keeps high plasmonic activity and suitable for high-frequency optoelectronic applications. GGA-PBE predicts higher mechanical strength and is more effective for studying band gap closure and optical absorption compared to LDA-CAPZ. CsPbI₃ is promising for solar energy devices due to its optical properties, while CsPbCl₃ and CsPbBr₃ are better for mechanically stable optoelectronic applications. Current research work findings support the potential of CsPbM₃ perovskites for practical applications as well as experimental validation.