Production of energy and its storage has become the main concern at the present time. Global environmental issues and the rising demand for a powering system of portable electronic devices as well as zero gaseous emission vehicles triggers research towards high energy and high voltage systems. Although Liion batteries have conquered the portable electronic market, yet its limited availability, high cost and safety issues have led to the search its alternatives. Na-ion and K-ion batteries may turn out to be a promising candidate for storage devices as they are cheaper and have higher energy density as compared to Li metals. We have proposed a fundamental theoretical design based on cubic double antiperovskite structure X 6 SOA 2 (X = Na, K; A = Cl, Br and I) by fullpotential augmented plane wave (FP-LAPW) method as implemented in the WIEN2k code within the density functional theory (DFT). We have calculated structural, electronic, optical, elastic, and thermodynamic properties and may be concluded that these materials are mechanically, dynamically, and thermally stable and have profound characteristics in high UV energy range. As these double antiperovskites have been studied for the very first time, this study may unfold a new vista for more comprehensive experimental and theoretical investigations for the search for non-toxic, eco-friendly and cheaper energy storage devices.

No abstract

Numerous double perovskites have demonstrated their astonishing potential in several optoelectronic and optical communication areas. Cs2SnI6 has also attracted attention because of its unique vacancy-ordered structure. However, Cs2SnI6 fitted them as good absorbing material still we have attempted to dope Kr atom at the vacancy site to intensify absorption. Herein, we have enumerated the structural, electronic, optical, mechanical and thermoelectric properties of Cs2SnI6 and Cs2SnKrI6. All these physical properties have been computed using density functional theory based Wien2K simulation code. Cs2SnKrI6 exhibits the indirect band gap of ~ 1.36 eV and direct band gap of ~ 1.37 eV. Cs2SnI6 and Cs2SnKrI6 both are optically active in visible and near-infrared regions with high absorption. The optical conductivity and power factor are also increased to a substantial level after doping. We have studied the elastic properties to examine the mechanical stability of these materials. We have found B/G ratio of 2.64 and 2.07 for Cs2SnI6 and Cs2SnKrI6 respectively, which demonstrates the ductile nature. After getting these constructive results, we have concluded that power conversion efficiency will also stimulate up to a great extent by doping.

No abstract