Electro-optic and transport properties with stability parameters of cubic KMgX (X = P, As, Sb, and Bi) half-Heusler materials: Appropriate for green energy applications

Abstract

Due to their distinct characteristics and prospective uses in several disciplines, half-Heusler (HH) materials are a family of intermetallic compounds that have garnered a lot of attention. HH compounds have a cubic crystal structure and exhibit a wide range of electronic, optical, mechanical and thermoelectric characteristics. Direct bandgap acquired by the WC-GGA (TB[Formula: see text][Formula: see text][Formula: see text]mBJ) approach is 1.07[Formula: see text]eV (2.26[Formula: see text]eV), 0.61[Formula: see text]eV (1.71[Formula: see text]eV), 0.76[Formula: see text]eV (1.68[Formula: see text]eV), and 0[Formula: see text]eV (0.78[Formula: see text]eV) for KMgP, KMgAs, KMgSb, and KMgBi, respectively. Threshold power [Formula: see text] of KMgX ([Formula: see text], As, Sb, and Bi), starts from 2.218, 1.701, 1.674, and 0.776[Formula: see text]eV, so they exhibit the distinct peaks at 4.014, 3.742, 3.388, and 3.197[Formula: see text]eV, correspondingly. Among these materials, the maximum value of Seebeck coefficient (S) has been attained at 300[Formula: see text]K. Specifically, KMgP achieves the highest value of S at 3.134[Formula: see text]mV/K, followed by KMgAs at 2.947[Formula: see text]mV/K, KMgSb at 2.893[Formula: see text]mV/K, and KMgBi at 1.431[Formula: see text]mV/K, all in their respective p-type configurations. In order to determine the compound’s stability, we will explore the elastic and thermodynamic properties. We will also discuss their possible applications in photovoltaic and thermoelectric devices.