Study of Structural, Electronic, Optical, Mechanical, Thermal, and Thermoelectric Properties of MPSi3 [M = Al, Ga, In] Semiconductors by DFT Method

Abstract

In this study, a new semiconducting material, InPSi₃, has been explored using density functional theory (DFT) calculations, along with an investigation of the unexplored properties of the newly predicted AlPSi₃ and GaPSi₃ semiconductors. The negative formation energy, elastic constants, and positive phonon modes certify the stability of all three compounds. InPSi₃ is an indirect-band-gap semiconductor (1.58 eV), whereas AlPSi₃ and GaPSi₃ are direct band gaps with an E_g of 1.64 and 1.51 eV, respectively. We used DOS to investigate the nature of bonding. Additionally, optical coefficients, including the dielectric constant, refractive index, extinction coefficient, photoconductivity, optical absorption, reflectivity, and loss function, were computed. The mechanical behavior was studied by calculating elastic constants, elastic moduli, and brittleness indices. The thermal parameters, including Debye temperature, melting temperature, thermal conductivity, minimum thermal conductivity, thermal expansion coefficient, and specific heat capacity, have been investigated. The thermoelectric properties, including electrical conductivity (σ/τ), electronic thermal conductivity (K_e/τ), Seebeck coefficient (S), power factor (PF), and figure of merit (ZT), were calculated. The titled materials would be appropriate for individual solar cells or the top portion of tandem solar cells, owing to their appropriate band gap and optical absorption.