First-principles investigations of structural, optoelectronic and thermoelectric properties of Cu-based chalcogenides compounds

• Published in: Journal of materials science 2021-10, Vol.56 (28), p.15882-15897
• Main Authors: Benaadad, Merieme, Nafidi, Abdelhakim, Melkoud, Samir, Khan, Muhammad Salman, Soubane, Driss
• Format: Article
• Language: English
• Subjects: Absorptivity; Analysis; Chalcogenides; Characterization and Evaluation of Materials; Chemistry and Materials Science; Classical Mechanics; Computation & Theory; Converters; Copper; Crystallography and Scattering Methods; Density functional theory; Density functionals; Electric properties; Energy conversion efficiency; Energy dissipation; Energy gap; Figure of merit; First principles; Investigations; Materials Science; Mathematical analysis; Optical properties; Optoelectronic devices; Optoelectronics industry; Polymer Sciences; Power factor; Refractivity; Room temperature; Seebeck effect; Solid Mechanics; Thermal conductivity; Thermoelectric materials; Thermoelectricity; Wavelengths
• ISSN: 0022-2461; 1573-4803
• DOI: 10.1007/s10853-021-06325-y

The structural, electronic, optical and thermoelectric properties of copper-based ternary chalcogenides ACuSe 2 (A = Sc, Y and La) were investigated within the framework of the density functional theory (DFT). The electronic band structures and density of states exhibit that ScCuSe 2 and YCuSe 2 have the indirect band gaps, while LaCuSe 2 displays a direct band gap-type transition. The band structure calculations agree well with other results in the literature. The optical behavior of the studied materials was analyzed in terms of dielectric functions, refractive index, extinction coefficient, absorption coefficient, optical conductivity, reflectivity and energy loss factor. The refractive indices increase to the maximum values of 4.4, 4 and 4.1 at the short infrared and visible wavelengths for ScCuSe 2 , YCuSe 2 and LaCuSe 2 , respectively. Then, they decrease to get a value below 1.0 at the UV wavelengths. Moreover, the material response with temperature was investigated by Seebeck coefficient, figure of merit, specific heat capacity, power factor, thermal conductivity and susceptibility. The high Seebeck effect and large power factor values confirm the efficiency of these materials in thermoelectric energy converter technology. Among the three studied ternary materials, YCuSe 2 has the highest value of dimensionless figure of merit of 0.45 at room temperature. These results would probably provide a new route to the experimentalists for the potential usage and applications of ScCuSe 2 , YCuSe 2 and LaCuSe 2 in thermoelectric and optoelectronic devices.