Exploring the optoelectronic and transport properties of novel ternary spinel semiconductors via first-principles calculation

Abstract

Direct band gap ternary spinel semiconductors stand out for their tunable optoelectronic features and excellent thermal stability. Using the known density functional theory, we studied the interactions of the structural, optoelectronic, and transport features of novel direct band gap Y2MgX4 (X=S, Se) spinel ternary materials. The lowest energy for each structure was calculated by computing the total energy values associated with numerous volumes after the structure had relaxed. The valence band maximum and conduction band minimum were located at the Γ-point of BZ, providing a direct energy gap forboth materials. The components of the complex dielectric function, such as absorption coefficients, loss functions, optical conductivity, reflectivity, refractive index, and extinction coefficient were considered to determine their potential efficacy in optical devices. The peaks in ε1(ω) decline and approach the negative energy area for both materials, indicating metallicity within this range. The greatest absorption coefficient peaks for both materials were found around 13.5 eV, indicating that Y2MgS4 and Y2MgSe4 are appropriate choices for UV optoelectronic applications. The significant increase in the ZT at low temperatures may indicate that the materials used have valuable properties at these temperatures.