Title
Structural, electronic and optical properties of ABTe2 (A = Li, Na, K, Rb, Cs and B = 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 hybrid
HSE06 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.