First-principles calculations to investigate HgY2S/Se4 spinel chalcogenides for optoelectronic and thermoelectric applications

Abstract

Spinel chalcogenides have great potential for optoelectronic and thermoelectric applications and therefore received huge attention in recent years. In this regard, here we investigate the structural, optical, electronic, and thermoelectric characteristics of HgY2S4 and HgY2Se4 spinel chalcogens using a density functional theory-based WIEN2k package. Ground state optimization of crystal structure and thermodynamic stability of the material is probed from the energy volume optimization graph and computation of enthalpy of formation. The computation of Poisson's and Pugh's ratios revealed the ductile nature of these materials. Bandgap calculation is performed using TB-mBJ package, which exposed the direct band nature of these semiconducting materials with bandgap values of 1.2 eV for HgY2S4 and 0.6 eV for HgY2Se4. The evaluation of optical characteristics and transport features revealed these compositions’ potential for optoelectronic and thermoelectric applications.

Keywords

• HgY2S/Se4 spinels
• Ab-initio calculations
• Direct small bandgap semiconductors
• Optical characteristics
• Thermoelectric efficiency