Intrinsic magnetism and thermoelectric applicability of novel halide perovskites Cs2GeMnX6 (X = Cl, Br): Route towards spintronics and energy harvesting technologies

Abstract

Novel halides becomes a point of prestige due to their intriguing multi-dimensional applications. In this work, strict and highly accurate spin-polarized Density Functional Theory (DFT) combined with Boltzmann transport scheme has been applied to extract the properties of new class of Pb-free prototypical halide semiconductors Cs2GeMnX6 (X = Cl, Br). The structural composition of these alloys suitably prefers their cubic crystalline geometry not only at room temperature but at higher temperatures also. The electronic properties were executed by Pedrew-Burke and Ernzerhof (PBE-GGA) in addition with the strong on-site Hubbard-parameter (U) implemented on Mn-partially filled d states to designate the complete understanding regarding their electronic structures. The inclusion of two calculation schemes claims p-type indirect semiconducting band profiles with the enhancement of band gap follows the trend GGA < GGA + U. The semiconducting nature at different symmetric points with ultra-spin splitting results ferromagnetic magnetic character of 5μB leads to the promising route towards spintronics. Elastically and mechanically these alloys are characterized to show brittle/ductile capability. Conservative estimates of Seebeck coefficient gears its extending application stand in thermoelectric energy harvesting technologies. The compact overview on these FM halide perovskites can develop into other highly dynamic research fields with vast implications for high-performance spin optoelectronics, spintronics, thermoelectrics and topological devices.