First-principles calculations of Sc2CdS4 and Y2CdS4 compounds

Abstract: Direct energy bandgap materials are crucial for the efficient optoelectronics devices. Therefore, the investigation of new direct gap materials is important. In the present work, two novel d-metal sulfides Sc2CdS4 and Y2CdS4 compounds are investigated by using the all electron full potential linearized augment plane wave method. Both the compounds show semiconducting nature and direct band gap with a value 1.886eV for Sc2CdS4 and 2.209eV for Y2CdS4, respectively. Strong hybridization between S-p and Sc/Y-d orbitals present among valence and conduction bands which is beneicial to electrical transport. Key optical parameters are calculated. The static value of the reflectivity R(0) and refractive index n(0) are vary inversely with the energy band gap (Eg). Both the compounds Sc2CdS4 and Y2CdS4 are P-type thermoelectric materials because the Hole carriers dominate the electronic transport. High optical and thermal response for all compounds reveals that they are potential candidates for optical and thermoelectric devices.