A first-principles study on structural, electronic, optical and thermal characteristics of A₃BF₃ (A = Mg, Ca, Sr, Ba; B = N, Bi) perovskites towards multifunctional applications

Abstract

Abstract This paper examines the structural, mechanical, electronic, optical, and thermal characteristics of A 3 BF 3 perovskite (A = Mg, Ca, Sr, Ba; B = N, Bi) materials through density-functional theory (DFT) computations. The calculations were performed using Quantum ESPRESSO, and the Phonopy and Thermo_pw packages were employed to analyze phonon and thermal properties, respectively. It is found that elastic constants show positive mechanical when these compounds are crystallized in the Pm-3m cubic system. Electronic structure analysis reveals that Mg 3 NF 3 and Mg 3 BiF 3 have high insulating behavior while Ca 3 BiF 3 , Sr 3 BiF 3 and Ba 3 BiF 3 are semiconductors with suitable bandgap for optoelectronic application. For instance, Ba 3 BiF 3 has a high rate of visible absorption, and minimal reflectance, which will make it suited for applications in photovoltaic devices. The absorption coefficient α(ω) varies between 10 5 to 10 6 cm −1 near the absorption edges, with Ba 3 BiF 3 exhibiting the highest absorption in the visible region, making it a promising candidate for high-efficiency solar cells and photovoltaic devices. Reflectivity analysis shows that Ba 3 BiF 3 and Sr 3 BiF 3 have comparatively low reflectivity in the visible and UV ranges, which reduces energy loss and enhances light harvesting efficiency. The optical properties of the compounds suggest their use in solar cell fields while thermal properties make compounds useful in thermal barrier coatings and energy-efficient technologies and systems at high temperatures. All in all, the A 3 BF 3 compounds demonstrate the set of properties which may contribute to their use in future-generation solar cells, optoelectronics, and advanced thermal management materials.

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