Insights on structural, elastic, electronic and optical properties of double-perovskite halides Rb2CuBiX6 (X=Br, Cl). (August 2022) - Hu, De-Yuan
Abstract: In this paper, the structural, elastic, electronic and optical properties of double-perovskite halides Rb2 CuBiX6 are studied using first-principles calculations based on density functional theory. The results show that Rb2 CuBiX6 (X = Br, Cl) have thermodynamic and mechanical stability according to the tolerance factor, binding energy, formation energy and Born-Huang stability criterion. The B/G value and Poisson's ratio indicate that Rb2 CuBiX6 is a flexible material. Rb2 CuBiBr6 and Rb2 CuBiCl6 are indirect bandgap semiconductors with bandgap values of 1.11 eV and 1.43 eV, respectively. In addition, the effective masses of electrons of Rb2 CuBiX6 are much smaller than that of other perovskite compounds, indicating that they have better carrier mobility. In the visible light range, Rb2 CuBiX6 has good dielectric properties and excellent light absorption properties. Therefore, Rb2 CuBiX6 has great potential in photovoltaic application due to their suitable bandgap values and excellent optical properties. Highlights: The bandgap values of Rb2 CuBiX6 (X = Br, Cl) are very suitable for photosensitive materials of solar cells. The Rb2 CuBiX6 can be a potential candidate for excellent light absorbing material. Rb2 CuBiX6 is the structural and thermodynamic stabilities.