Title
Structural, electronic and optical properties of ABTe2 (A ¼ Li, Na, K, Rb, Cs and B ¼ Sc, Y, La): Insights from first-principles computations
Document Abstract
In this contribution, ternary telluride ABTe2 compounds are proposed as promising candidates for n-type semiconductor
materials in photovoltaic and photochemical devices. We report the successful calculations of the most
fundamental properties needed in the previous applications such as the effective mass, dielectric constant and the
exciton binding energy. This latter one has been evaluated from the density functional theory (DFT) method in the
first time for these materials. An easy dissociation for hole-electron pair is suggested due to the small value of
exciton binding energy at room temperature (i.e., lower than the thermal energy, 25 meV) for most of the studied
compounds. The band structure and density of states of ABTe2 are calculated using the hybridHSE06 functional,
PBE0 and in addition the pure GGA-PBE functionals. Additionally, to elucidate the optical properties of these
compounds, the complex dielectric function and optical reflectivity were computed for a wide range of photon
radiation. Therefore, ABTe2 materials are expected to be promising candidates for visible light driven photovoltaic
and photocatalytic devices.