Electronic, optical and thermoelectric properties of the WS2–GaN interfaces: a DFT study

Abstract

Based on the density function theory, the electronic, optical, and thermoelectric behaviors of the WS2–GaN interfaces have been investigated at three d1 = 2.8793 A, d2 = 4.0459 A, and d3 = 6.6419 A distances. All compounds have the ground state point with high hardness. The WS2–GaN interfaces for d1 and d3 cases are the p-type semiconductors and the other one is n-type semiconductor, with 1.82 eV, 1.95 eV, and 1.51eVband gap, respectively, with high levels density around the Fermi level. Optical properties have been approximated by the RPA, TDDFT, and BSE approximations, which the last case has better agreement with the electronic nature of these compositions. The main optical response is occurred in the 5 eV optical energy for two x and z directions. The optical response with BSE approximation indicates the semiconductor behavior for all three interfaces in the infrared, visible and ultra-violate edge regions. The Seebeck coefficients for the d1 and d3 distances show that the holes are the charge carriers and for the other one electrons. In addition, the figures of merit at lower temperatures have been shown in WS2–GaN interfaces for d1 and d3 having good thermoelectric efficiencies with high amount of ZT.