Unveiling the optoelectronic and thermoelectric properties of YAgCh2 (Ch = Se, Te): First-principles study

Ternary chalcogenides’ unique structural and electronic properties have concentrated them as desirable materials for energy applications. In the present study, we used density functional theory (DFT) calculations to explore the optoelectronic and thermoelectric features of YAgSe₂ and YAgTe₂ materials. The cohesive energies for YAgSe₂ and YAgTe₂ were predicted to be −4.57 eV/atom and −4.76 eV/atom, respectively.. Both materials display no signs of dynamic instability, as indicated by the absence of imaginary modes, signifying that they are thermodynamically stable. Both materials show semiconducting properties, based on their electronic band structure, although YAgTe₂ has a narrower band gap than YAgSe₂, which renders it more suited for infrared absorption. The visible and near-infrared regions have high absorption coefficients, suggesting they could be used as absorber layers in optoelectronic devices. Furthermore, the important thermoelectric parameters are determined for evaluating thermoelectric performance. With low lattice thermal conductivity and favorable ZT, both materials exhibit potential thermoelectric efficiency, especially at high temperatures. The addition of YAgSe₂ and YAgTe₂′s optical and thermoelectric features makes them material choices for solar energy conversion and storage. The investigation highlights the potential of these materials for sustainable energy technologies and provides an extensive theoretical framework for comprehending their features. Our results suggest a direction for future experiments to explore and refine these chalcogenides for thermoelectric and solar applications.