The bandgap engineering of double perovskites Cs2CuSbX6 (X = Cl, Br, I) for solar cell and thermoelectric applications

• Published in: Inorganic chemistry communications 2023-02, Vol.148, p.110303, Article 110303
• Main Authors: Mera, Abeer, Nazir, Ghazanfar, Mahmood, Q., Kattan, Nessrin A., Alshahrani, Thamraa, Rehman, Adeela, Sultana, Hafeez, Amin, Mohammed A., Elhosiny Ali, H.
• Format: Article
• Language: English
• Subjects: Double Perovskites; Optical properties; Solar cell; Thermoelectric applications; Tunable bandgap
• ISSN: 1387-7003; 1879-0259
• DOI: 10.1016/j.inoche.2022.110303

(Left) Polyhedral structure of Cs2CuSbX6 (X = Cl, Br, I), and (Right) Figure of merit as a function of temperature (K). [Display omitted] •Lead-free double perovskites are more cheap, stable, and environmentally friendly materials for solar cells.•Cs2CuSbX6 (X = Cl, Br, I) explicates direct bandgap values 1.04, 0.75, and 0.46 eV by substituting Cl with Br and I, respectively.•The studied DPs are potential candidates for solar cells and infrared detectors.•The computed figure of merit (ZT) verifies optimal electrical conductivity and the Seebeck coefficient. Over recent years, the research on lead-free halide double perovskites (DPs)-based materials has credited attention because of their promising applications in solar cells and renewable energy. Herein, we tried to computationally analyze the optoelectronic as well as the thermoelectric characteristics of a unique compound Cs2CuSbX6 (X = Cl, Br, I) by density functional theory (DFT). The calculation of tolerance factor (tF), lattice constant (ao), and formation enthalpy (ΔHf) show that the investigated DPs are stable both structurally and thermodynamically. The value of bandgaps of Cs2CuSbX6 (X = Cl, Br, I) explicates indirect bandgaps with values 1.04, 0.75, and 0.46 eV for Cs2CuSbCl6, Cs2CuSbBr6, and Cs2CuSbI6, respectively. Further, maximum optical absorption between energy range “1.0 to 3.0 eV” has proved that studied DPs are potential candidates for solar cells and infrared detectors. By exploiting the semi-classical Boltzmann theory, the calculated figure of merit (ZT) verifies the optimal value for electrical conductivity and the respective Seebeck coefficient for the studied compounds. Interestingly, the compound Cs2CuSbCl6 has the highest ZT among studied DPs. The present study provides a theoretical base for the studied DPs which is necessary to understand and compare future experimental investigations to seek diverse optoelectronic and thermoelectric applications.