Investigation of the Structural and Thermodynamic Properties of Mgbs3 (B = Hf, Ti and Zr) Compounds for Photovoltaic Applications

Abstract

The plane wave pseudopotential method of QUANTUM-ESPRESSO within the generalized gradient approximation (GGA) was used to determine the structural, mechanical and thermodynamic properties of MgBS3 (B = Hf, Ti and Zr). Calculated formation energies showed these compounds are mechanically stable except MgTiS3 . The nine independent elastic constants obtained correlates with the Born-Huang mechanical stability criteria that led to other elastic quantities. The stress-strain relationship yielded the materials are highly compressible, largely anisotropic and ductile except for MgTiS3 with a brittle and non-metallic bonding. The elastic moduli and anisotropy factors were determined from the elastic constants. Further analysis with Pugh ratio confirms that MgZrS3 and MgHfS3 compounds are ductile while MgTiS3 is brittle in nature. Debye vibrational energies, entropies and constant volume heat capacities of the compounds showed a proportionate increase with an increasing temperature. These results will provide theoretical guidance for experimental investigations and industrial applications of these compounds.

Keywords: Chalcogenide-perovskites, mechanical, structural, thermal, photovoltaic and optoelectronics.