Abstract
From the last few decades, double perovskites are becoming the merging materials for solar cells and renewable energy applications. Here in this article, we have explored the electronic, optical, and thermoelectric characteristics of Rb
2
AgBiX
6
(X = Br, I) by using modified Becke and Johnson potential through density functional theory approach. The band gaps of 1.88 eV and 1.22 eV are computed for Rb
2
AgBiBr
6
and Rb
2
AgBiI
6
, respectively. The reduction in band gap occurs by the replacement of Br with I due to hybridization of cations and anions sub-states. The optical properties are addressed by absorption coefficient, refractive index, polarization of light, reflection, and energy loss factor. The absorption bands fall in ultraviolet region for Rb
2
AgBiBr
6
, and in visible region for Rb
2
AgBiI
6
which increases their potential for optoelectronics. The thermoelectric characteristics are addressed by figure of merit (ZT) scale. The ultralow thermal conductivity and large Seebeck coefficient increase their ZT to make them significant for thermoelectric generators.