The Comparision Of Electronic Structures Of CuGaTe₂and CuGaS₂Based On First-principles Calculations

In accordance to the principles of interaction between nuclei and electrons and its basic law of motion, with specific requirements we use the principles of quantum mechanics to directly solve the Schrodinger equation which using some approximation method, is called the First Principle customarily.The method of using the First Principle to calculate the electronic properties has been widely applied in the calculation for the basic properties and the linear nature of the semiconductor. Now more and more people are interested in the band structure and the density of states of the Ⅰ-Ⅲ-Ⅵ2compounds. Because the band and the density of states as the basic nature of the material, they provide electronic distribution of the theoretical basis for in-depth study of CuGaTe2and CuGaS2material other performance. CuGaTe2and CuGaS2are recognized as a ternary semiconductor compound, they have a chalcopyrite structure, and belong to a direct band gap semiconductor material. Reffer to the two similar compounds, There is a prominent feature of these ternary compounds:their band gap energy are reduced substantially. This can directly be reflected in the band structure and density of states. This is due to the hybrid role between p-orbital and d orbitals of different atomic, and the degree of orbital hybridization effect the strength of the bond between atoms and atoms.In this paper, we mainly use density functional theory (DFT) to calculate CuGaTe2and CuGaS2compounds some of the basic properties such as band structure and density of states, and adopt density functional perturbation theory (DFPT) to calculate CuGaTe2and CuGaS2response function, we can obtain the linear properties such as Bohr effective charge tensor, the dielectric tensor, the elastic tensor and the phonon frequency distribution at the center of the Brillouin zone. These properties are based on abinit package, using first-principles to calculate, using opium to generate pseudopotential, using the local approximation (LDA) of density functional theory to define the exchange-correlation energy. The calculations help solving the differences between experimental literature and theoretical literature.