First-principles study of optoelectronic and thermoelectric aspects of novel zintl phase SrAg2X2 (X = S, Se, Te) alloys for green energy applications

This work comprehensively investigates the solar energy harvesting and thermoelectric capabilities of innovative Zintl phase SrAg₂X₂ (X = S, Se, Te) alloys. Herein, the analysis of the structural, optoelectronic, and thermoelectric characteristics of Zintl SrAg₂X₂ (X = S, Se, Te) compounds has been conducted utilizing the WIEN2k code. The formation energy has been evaluated to elaborate the thermodynamic stability of Zintl compounds. The materials demonstrate characteristics of semiconductors, with anticipated band gap values of 1.78 eV for SrAg₂S₂, 1.63 eV for SrAg₂Se₂, and 1.50 eV for SrAg₂Te₂. The optical characteristics have been examined to assess the potential use of these phases in optoelectronic and photovoltaic systems. The standard Boltzmann transport theory has been used to analyze thermoelectric parameters concerning temperature and chemical potential. Thermoelectric features have also verified the p-type characteristics of these semiconductors. Considerably higher predicted values of the power factor and higher figure of merit demonstrate the capability of thermal energy conversion. Consequently, these outstanding optoelectronic and thermoelectric aspects values indicate that this class of materials may be highly suitable for use in solar and thermoelectric systems.