Thermoelectric performance of cadmium-based LiCdX (X = N, P, As, Sb and Bi)-filled tetrahedral semiconductors: applications in green energy resources

Half-Heusler materials have been studied on a large scale due to their high stability and wide range of band gaps. Here, we have studied the fundamental physical and thermoelectric parameters of LiCdX (X = N, P, As, Sb and Bi) and observed that these compounds have F43m space group with 5.31, 6.06, 6.25, 6.64 and 6.81 Å lattice constants for LiCdN, LiCdP, LiCdAs, LiCdSb and LiCdBi, respectively. All compounds exhibit direct band- gap semiconducting behaviour except LiCdBi which shows a metallic nature. In near-infrared and visible regions, these compounds show excellent photovoltaic behaviour, but they restrict far-infrared and ultraviolet radiation. By examining thermoelectric characteristics, we have analysed that at 300 K, ZT achieves unity in both the p- and n- regions for three of these materials, making them prospective thermoelectric candidates at ambient temperature. The studied thermodynamic properties have confirmed that materials are stable which will motivate experimentalists. (author)