Optoelectronic and thermoelectrical and mechanical properties of CdLu2X4 (X = S, Se) using first-principles calculations for energy harvesting applications

Abstract

First-principles study of spinel compounds CdLu2X4 (X = S, Se) has been carried out using density functional theory based Wien2k code. Lattice parameters are consistent with the experimental data. Born's stability criteria confirm the mechanical stability, while the Poisson coefficient (ν > 0.26) and the Pugh ratio (B0/G > 1.75) certifies the ductile nature of the compounds. Tran and Blah modified Becke-Johnson exchange potential was employed, which gives accurate values of direct bandgap 2.08/1.44 eV for CdLu2S4/Se4. The maximum absorption of photon energy in the visible to the ultraviolet region is found. The high absorption in ultraviolet and visible regions makes them good candidates for solar cells and energy storage devices. Thermoelectric properties are studied using BoltzTrap code in terms of electrical and thermal conductivity, Seebeck coefficient, power factor, and figure of merit.