Unveiling the structural, optical coating and thermoelectric characteristics of kesterite-quaternary chalcogenides Ag2InGaX4 (X = S, Se, Te) via DFT study

This study explores the distinctive features of novel kesterite-type chalcogenide semiconductor materials through a new scheme designated as I₂-III-III-VI₄, focusing on Ag₂InGaX₄ (X = S, Se, Te). The investigation employs density functional theory (DFT) using the advanced all-electron full potential linear augmented plane wave(FP-LAPW) method. The exchange-correlation potential is assessed through the Perdew–Burke–Ernzerhof (PBE) parameterization, complemented by the Tran–Blaha modified Becke–Johnson (TB-mBJ) exchange potential estimation.Furthermore, thermodynamic parameters are analyzed in relation to temperature and pressure for the selected materials, utilizing the quasi-harmonic model. The electronic structure analysis reveals that Ag₂InGaX₄ (X = S, Se, Te) materials display semiconducting behavior, with direct band gaps measured at 1.9 eV, 1.1 eV, and 0.86 eV, respectively.Moreover, the predicted refractive index, absorption coefficient, dielectric function, absorbance, transmittance and reflectance revealed that Ag₂InGaX₄ (X = S, Se, Te) are promising materials for photovoltaic and optoelectronic devices. Furthermore, the analysis of thermoelectric properties considering the Seebeck coefficient, thermal conductivity, electronic conductivity, and highly valued figures of merit showed that the studied kesterite-type compounds have strong potential for applications in the fields of thermoelectric power energy.Finally, all these results are considered favorable and appropriate as per the characteristics mentioned earlier, and their potential advantages and applications in advanced hybrid photovoltaic and thermoelectric systems have been highlighted. It has been declared that this study's attained results were considered a prediction in this kesterite family.