First-Principles Investigation of Li2AuSbZ6 (Z = Cl, Br, I) Double Perovskites for Photovoltaic and Thermoelectric Applications

초록

The halides-based double perovskites (HDPs) have become a promising materials in photovoltaic and thermoelectric (TE) devices because they have a stable structure and environmentally friendly. Thus, in the present article, physical properties of HDPs Li2AuSbZ6 (Z = Cl, Br, I) are described in detail. Tolerance factors are calculated to provide stability of cubic phases, and negative values of formation energy has been reported to provide thermodynamic stability. Born stability criteria, ductility and hardness are used to analyze the mechanical aspects. Further, electronic properties indicate all HDPs are indirect bandgap semiconductors having bandgap values 1.3, 0.7, and 0.2 eV for Li2AuSbCl6, Li2AuSbBr6, and Li2AuSbI6, respectively. Li2AuSbCl6 halide used as potential candidate for photovoltaic systems because of their bandgap value. Besides, dielectric constants, absorption, and reflectance have been used to explain optical characteristics. High absorbance in the visible range are expected to find photovoltaic applications. The transport properties like electrical and thermal conductivity, as well as the Seebeck coefficient, were closely examined. Li2AuSbBr6 and Li2AuSbCl6 are highlighted as the best choices for TE devices due to their nearly identical ZT values around 0.61, respectively.

키워드