Ab‐initio study of opto‐electronic and thermoelectric properties of direct bandgap double perovskites Rb ₂ XGaBr ₆ (XNa, K)

Abstract

Double perovskite halides are potential materials for the production of renewable energy that could meet the global demands for resolving energy shortage issues. In this study, we systematically investigate the Rb 2 XGaBr 6 (X Na, K) double perovskites using the full-potential linearized augmented plane wave (FP-LAPW+lo) method of density functional theory. The thermodynamic as well as the structural stabilities of the studied materials have been confirmed from the calculated formation energy and Goldsmith tolerance factor (0.89 and 0.92). On the other hand, the calculated Pugh's ratio shows the ductile mechanical nature of the studied materials. The calculated electronic bandgaps of 2.2 eV/1.90 eV for Rb 2 Na/KGaBr 6 lies is in the visible region, which indicated the potential application of these materials in solar cells. The electronic properties of the two compounds are studied using the electronic density of states and the complex dielectric functions are used to evaluate optical properties. Our calculated results clearly indicate the optimum absorption of light in visible regions which depicts the potential of these materials for optoelectronic devices. The thermoelectric properties of the two Rb 2 XGaBr 6 (X Na, K) double perovskites are also studied in terms of thermal and electrical conductivity and the Seebeck coefficient. K E Y W O R D Sdensity functional theory, direct band gap double perovskite, figure of merit, mechanical characteristics, opto-electronic devices

Cs2TlRhX6 (X = Cl, Br, I): promising halide double perovskites for efficient energy harvesting in photovoltaic and thermoelectric applications

“…Where r , A r B r X are the radius of Cs + , the mean radius of sites B + and B +3 and radius of halides respectively. [17]. The estimated tolerance, octahedral and modified tolerance factors are reported in table 1.…”

Probing optoelectronic and thermoelectric properties of double perovskite halides Li2CuInY6 (Y = Cl, Br, I) for energy conversion applications

“…Among DPHs, recently Li-based DPHs Li 2 CuBiZ 6 (Z=Cl, Br and I) and Li 2 AgGaX 6 (X = Cl, Br, I) explored theoretically for the manufacturing of optoelectronic and thermoelectric device applications using density functional theory [13,14]. Their finding of direct bangap nature indicate all DPHs potential candidate for photovoltaic devices.…”

Understanding the role of 5d electrons in ferromagnetism and spin-based transport properties of K2W(Cl/Br)6for spintronics and thermoelectric applications

“…For instance, Haq et al predicted that Rb 2 XGaBr 6 (X = Na, K) are promising photovoltaic and thermoelectric materials due to their optimum optical absorption coefficient and large ZT values, respectively. 52 Later, Iqbal et al have shown the emerging photovoltaic and thermoelectric properties of Rb 2 AlInX 6 (X = Cl, Br, I) due to their narrow band gap. 53 Also, Nawaz et al reported that Rb 2 YInX 6 ( X = Cl, Br, I) are thermodynamically stable and they are suitable for photovoltaic and thermoelectric technology.…”