First‐Principles Study of Ag 2 InGaTe 4 and Related Tellurides as High‐Efficiency Solar Absorber Materials

This study employs first‐principles calculations to explore the structural, electronic, and optical coating properties of Ag‐based ternary and quaternary chalcogenide compounds. Elastic constants satisfy all Born stability criteria, and the Pugh ratio B/G , with values exceeding 2, classifies all studied compounds as inherently stable and ductile materials. The findings indicate that all compounds investigated are direct bandgap semiconductors, with bandgap values of 0.963 eV for AgGaTe 2 , 0.736 eV for AgInTe 2 , 0.49 eV for Ag 2 CdSnTe 4 , and 0.868 eV for Ag 2 InGaTe 4 . Analysis of optical properties shows that all thin‐films demonstrate high absorbance (∼75%) in the visible spectrum for film thicknesses greater than 1600 nm. Additionally, the computed absorption coefficients, approximately 10 4 cm −1 , affirm the strong light‐harvesting capability of these materials, making them promising candidates for solar cell absorber layers. The spectroscopic limited maximum efficiency (SLME) was assessed, revealing a significant increase for wavelengths beyond 500 nm, with maximum theoretical efficiencies of 29.22% for AgGaTe 2 , 24.30% for AgInTe 2 , and 27.91% for Ag 2 InGaTe 4 , all aligning with optimal bandgap values between 0.73 and 1.0 eV. These results indicate that the newly investigated quaternary compound Ag 2 InGaTe 4 displays exceptional optoelectronic properties, indicating its potential as a strong candidate for thin‐film solar cell applications.