探索用于能源应用的铯基双卤化物钙钛矿：热电、光学和自旋极化磁性研究

In this study, the thermoelectric, optical, and spin-polarized magnetic properties of double halide perovskites Cs 2 SrTaCl 6 , Cs 2 SrTaBr 6 , and Cs 2 BaTaBr 6 are systematically investigated to assess their potential for photovoltaic and related optoelectronic applications. The calculated thermal conductivity values follow the trend: Cs 2 SrTaCl 6 (2.68 × 10 14 W/m·K·s) > Cs 2 BaTaBr 6 (2.32 × 10 14 W/m·K·s) > Cs 2 SrTaBr 6 (2.19 × 10 14 W/m·K·s). The corresponding power factor values are found to be: 2.69 × 10 10 W/m·K 2 ·s for Cs₂SrTaCl₆, 2.59 × 10 10 W/m·K 2 ·s for Cs 2 BaTaBr 6 , and 2.39 × 10 10 W/m·K 2 ·s for Cs 2 SrTaBr 6 . Optical analysis reveals peak real dielectric constants near 6.0 eV as follows: Cs 2 SrTaBr 6 (5.14) > Cs 2 BaTaCl 6 (4.77) > Cs 2 SrTaCl 6 (4.70). The static refractive indices are: Cs 2 SrTaBr 6 (2.45) > Cs 2 BaTaCl 6 (2.26) > Cs 2 SrTaCl 6 (2.17). Spin-polarized magnetic calculations indicate paramagnetic behavior in all three compounds. The magnetic integrated spin density values are 3.36 ħ/2 for Cs 2 BaTaCl 6 , 3.35 ħ/2 for Cs 2 SrTaCl 6 , and 1.34 ħ/2 for Cs 2 SrTaBr 6 , respectively. These findings highlight the promising multifunctional nature of these perovskites for thermoelectric and photovoltaic device applications.