Insight into the electronic, optical, and thermoelectric properties of novel ternary chalcohalides: next-generation energy applications

Due to their unique electronic structures and adjustable physical properties, ternary chalcohalides semiconductors are a class of materials with great potential for next-generation optoelectronic and thermoelectric applications. In this work, we examined the electronic, optical, and thermoelectric transport properties, along with the cohesive and formation energies of novel YSeM (M = Cl, Br) ternary chalcohalides using density functional theory. Both materials are found to be direct band gap materials having band gaps of 1.76 eV and 1.56 eV for YSeCl and YSeBr, respectively, using the PBE-GGA. Also, the band gaps obtained using the HSE06 are 2.69 eV and 2.18 eV, respectively. The sharp peaks in the reflectivity suggest these materials as active ultraviolet-reflecting materials and can be used in the ultraviolet protection applications. The negative Seebeck coefficient of these materials reveals that they show n-type conductivity. Due to their direct band gap nature and desirable thermal performance, they appear to hold considerable potential for applications in an extensive range of cutting-edge technologies.