[114] Optoelectronic and thermoelectric response of lead free halide double perovskites Rb₂AgPX₆ (X=Cl, Br, I) for energy storage applications

In this study, we have thoroughly examined the electro-optics and thermal properties of Rb2AgPX6 (X = Cl, Br, I), using ab-initio simulations. We find the Rb2AgPX6 (X = Cl, Br, I) have lower energies, exhibiting the favorable nature. Furthermore, we find that our studied configuration exhibits ductile nature due to higher Pugh’s ratio. Additionally, the non-negative frequencies in the phonon spectra confirm the dynamical stability of Rb2AgPX6 (X = Cl, Br, I). We observe, an indirect band gap ranging from 0.81 eV to 1.60 eV for Rb2AgPX6 (X = Cl, Br, I) uing mBJ + SOC. Moreover, the optical absorption confirm the electron transitions from the valence band to the conduction band due to sharp peak in the spectra. According to the AM 1.5 spectra, the light absorption occurs below 4.0 eV, showing the applications of Rb2AgPX6 (X = Cl, Br, I) suitable for solar cells. Furthermore, the zT value for Rb2AgSbCl6 is 0.73 and for Rb2AgSbBr6 is 0.76, exhibiting its applicability in the thermal devices at room temperature. Thus, our calculated results could be useful as a basis for future (experimental) studies that investigate the characteristics of Rb2AgSbX6 (where X = Cl, Br, I) in terms of renewable energy devices and applications.