Electronic, optical, and transport properties of ternary α3Vβ4 (α = Cu, Ag, and β = S, Se, Te) for energy harvesting: A DFT insights

First-principles study investigates the optoelectronic and transport properties of novel transition metal-based ternary, I 3 -V-VI 4 family chalcogenide semiconductors in formula α 3 Vβ 4 (α = Cu, Ag, and β = S, Se, Te) with an emphasis on their potential for energy applications. The optimized structural parameters of α 3 Vβ 4 are in good agreement with available results. The electronic band structures reveal the indirect bandgap semiconductor nature of α 3 Vβ 4 with values in the range of E g ~1.05-0.47 eV. The density of states (DOS) exhibits that, as the atom substation from S → Se → Te occurs, the bandgap value decreases owing to the upward movement of valence-band maxima (VBM) to the higher energy region and downward movement of conduction-band minima (CBM) to the lower energy region, revealing that heavy chalcogen atom replacement promotes orbital hybridization. The failure mode analysis specifies the brittle nature in Cu-based whereas ductile behavior in Ag-based compounds under this scheme. Further, the various optical properties are investigated to realize the optical behavior of the investigated ternary compounds. The calculated excitonic binding energy and exciton Bohr radius also indicates the suitability for photovoltaic applications. The different transport properties, such as Seebeck coefficient, electrical and electronic thermal conductivities, molar specific heat capacity, and power factor (P.F.) of the studied semiconductors are analyzed. Overall, the investigated results highlight the potential of α 3 Vβ 4 compounds in applications. • DFT study is performed on α 3 Vβ 4 (α = Cu, Ag, and β = S, Se, Te) compounds. • Bandgaps are found in the range of 1.05-0.47 eV for the compounds. • Mechanical stability of the compounds are confirmed from the study. • Transport properties of the compounds have been calculated. • The findings are promising for their applications in energy harvest.