Exploring the electronic and optical anisotropy of quasi-one-dimensional ternary chalcogenide CrSbSe3: a DFT study

Abstract

The anisotropy of the electronic and optical properties of the quasi-one-dimensional ternary transition metal chalcogenide CrSbSe3 is investigated using density functional theory (DFT) including the on-site Coulomb self-interaction potential (DFT + U) and spin-orbit interaction. The compound is an indirect bandgap semiconductor with bandgap of 0.58 eV. Effective masses and charge recombination rates along different directions show appreciable anisotropy, indicating the possibility of sensor applications. CrSbSe3 exhibits satisfactorily high carrier mobility and charge recombination rates along all directions, making it suitable for solar and photovoltaic applications. The Se-p and Cr-d orbitals contribute to the DOS in the valence band, while DOS contribution to the conduction band bottom comes mainly from Sb-p and Cr-d orbitals. Simulated XPS and HAXPES show that for soft x-rays, the peak in the low binding energy is due to the electron emission from Se-p and Cr-d orbitals while the peak in the high binding energy is due to the electron emission from Cr-d and Se-s orbitals. For hard x-rays, the relative intensity of the low binding energy peak decreases in comparison to the high binding energy peak, indicating enhanced electron emission from Se-s orbitals at higher energy x-rays. CrSbSe3 possesses large anisotropy in optical parameters such as refractive index, optical absorption, reflectivity, optical conductivity and optical extinction. The birefringence and dichroism are large in the IR, visible and near UV regions, with a giant birefringence equal to 0.56 at 650 nm and dichroism equal to 0.57 at 550 nm. The electron energy loss function is anisotropic for high energetic electrons, while for electrons below 4 eV it is isotropic. CrSbSe3 is an ideal material for photovoltaic, sensor and other optoelectronic applications as it possesses a bandgap of 0.58 eV, large optical anisotropy, high values of dielectric constant, refractive index, absorption coefficient and extinction coefficient.