Insights on structural, elastic, electronic and optical properties of double-perovskite halides Rb2CuBiX6 (X=Br, Cl)

• Published in: The Journal of physics and chemistry of solids Vol. 167; p. 110791
• Main Authors: Hu, De-Yuan, Zhao, Xian-Hao, Tang, Tian-Yu, Li, Li, Tang, Yan-Lin
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.08.2022
• Subjects: Electronic structure; Mechanical properties; Optical properties; Rb2CuBiX6; Mechanical properties; Rb2CuBiX6; Electronic structure; Optical properties
• ISSN: 0022-3697; 1879-2553
• DOI: 10.1016/j.jpcs.2022.110791

In this paper, the structural, elastic, electronic and optical properties of double-perovskite halides Rb2CuBiX6 are studied using first-principles calculations based on density functional theory. The results show that Rb2CuBiX6 (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 Rb2CuBiX6 is a flexible material. Rb2CuBiBr6 and Rb2CuBiCl6 are indirect bandgap semiconductors with bandgap values of 1.11 eV and 1.43 eV, respectively. In addition, the effective masses of electrons of Rb2CuBiX6 are much smaller than that of other perovskite compounds, indicating that they have better carrier mobility. In the visible light range, Rb2CuBiX6 has good dielectric properties and excellent light absorption properties. Therefore, Rb2CuBiX6 has great potential in photovoltaic application due to their suitable bandgap values and excellent optical properties. •The bandgap values of Rb2CuBiX6 (X = Br, Cl) are very suitable for photosensitive materials of solar cells.•The Rb2CuBiX6 can be a potential candidate for excellent light absorbing material.•Rb2CuBiX6 is the structural and thermodynamic stabilities.