Effect of lattice deformation on electronic and optical properties of CuGaSe2: Ab-initio calculations

In this study, we have investigated the effect of bi-axial, ?ab, and uni-axial, ?c, strains on the optoelectronic properties of chalcopyrite semiconductor CuGaSe2 through first-principles full potential linearized augmented plane wave method. These materials have recently attracted much interest within the materials science community. The results are obtained in the framework of Density Functional Theory (DFT), using the Generalized Gradient Approximation based on the minimization of total energy, together with the modified Becke-Johnson exchange-correlation potential, as implemented in the WIEN2k code. Our results show that unstrained CuGaSe2 is a direct band gap semiconductor with a energy of 1.16 eV, thus improving the results of some previous DFT calculations, but still below the accepted experimental data. The incorporation of biaxial and uniaxial strain results in a monotonous decreasing behavior of the energy band gap when both ?ab and ?c change between -8% and +8%, with unstrained value being, approximately, at the middle of the variation range. It is also found that strain causes modifications in the index of refraction of the material, with modifications of its static value that rank above 10% over the entire range of deformations considered. © 2019 Elsevier B.V.

• Fecha de publicación: 2020
• Institución: Universidad de Medellín
• Repositorio: Repositorio UDEM
• Idioma: eng
• OAI Identifier: oai:repository.udem.edu.co:11407/5791
• Acceso en línea: http://hdl.handle.net/11407/5791
• Palabra clave: Copper gallium selenide; Density functional theory; Electronic properties; First-principle calculations; Optical properties; Strain effect; Calculations; Copper compounds; Deformation; Electronic properties; Energy gap; Layered semiconductors; Optical lattices; Optical properties; Refractive index; Selenium compounds; Semiconducting gallium compounds; Semiconducting selenium compounds; Strain; Direct band gap semiconductors; Electronic and optical properties; Exchange-correlation potential; First principle calculations; Full potential linearized augmented plane wave method; Gallium selenides; Generalized gradient approximations; Strain effect; Density functional theory
• License: http://purl.org/coar/access_right/c_16ec