First‐principles investigation of structural, optoelectronic, and thermoelectric properties of Cs2Tl(As/Sb)I6. (25th March 2022)

• Record Type: Journal Article
• Authors: Sk, Mukaddar; Ghosh, Saurabh
• Other Names: Bicer Yusuf guestEditor.
• Is Part Of: International journal of energy research. Volume 46:Number 8(2022)
• Page Start: 10553
• Page End: 10563
• Publication Date: 2022-03-25
• Subjects: absorption coefficient -- figure of merit -- optical conductivity -- optical properties -- thermoelectric; Power resources -- Periodicals; Power (Mechanics) -- Periodicals; Power resources -- Research -- Periodicals; 621.042
• DOI: 10.1002/er.7830
• Languages: English
• ISSNs: 0363-907X

Abstract

Summary: In this article, we have systematically investigated the structural, electronic, optical, and thermoelectric properties of Cs2 Tl(As/Sb)I6 . The obtained negative formation energy along without the presence of imaginary phonon frequency confirmed the thermodynamic stability of Cs2 Tl(As/Sb)I6 . In addition, the new mBJ approach showed the direct band gap value of 1.10 and 1.33 eV for Cs2 TlAsI6 and Cs2 TlSbI6, respectively. Furthermore, the dispersed direct band nature of Cs2 Tl(As/Sb)I6 leads to their outshining optical properties such as higher‐order (10 5 cm −1 ) absorption coefficient, appreciable optical conductivity, and low reflectivity. Moreover, the higher figure of merit values of Cs2 Tl(As/Sb)I6 are resulted from their ultra‐low thermal conductivity and high electrical conductivity. Thus, Cs2 Tl(As/Sb)I6 are predicted to be potential photovoltaic and thermoelectric materials. Abstract : The predicted direct band gap values are 1.10 and 1.33 eV for Cs2 TlAsI6 and Cs2 TlSbI6, respectively. In addition, the optical studies revealed the higher order of absorption coefficient, appreciable optical conductivity and low reflectivity, which demonstrate that Cs2Tl(As/Sb)I6 compounds are emerging photovoltaic materials. Furthermore, the ultra‐low thermal conductivity and high electrical conductivity leads to the large figure of merit values of Cs2 Tl(As/Sb)I6 .