First-principles calculation for electronic, optical and transport properties of SnTe: A DFT study with different exchange-correlation potentials

Abstract

This study reports the first-principles investigation of electronic, optical and transport properties of SnTe employing three exchange-correlation potentials: local density approximation (LDA), generalized gradient approximation (GGA) and GGA with the Tran-Blaha modified Becke-Johnson (GGA + TB-mBJ) within density functional theory (DFT) using WIEN2k code. Our comparative analysis indicates that GGA yields better structural stability and the electronic band structure computed using TB-mBJ gives better result which aligns closely with the experimental result in comparison to those obtained using LDA and GGA. The initial two methods indicated a semi-metallic nature while the GGA + TB-mBJ approach demonstrated a semiconductor behavior with a band gap of 0.27 eV. We also explore optical properties including conductivity, absorption coefficient, energy loss function, optical reflectivity, refractive index and extinction coefficient under ambient conditions. Furthermore, we calculate the Seebeck coefficient, electrical conductivity and power factor across a temperature range of 300 K–1000 K using BoltzTraP2 in WIEN2k.