Exploration of the electronic structure and thermoelectric properties of the carbon-doped bulk GaN materials by first-principles calculations

As a common impurity, carbon was related to the physical properties of GaN-based materials closely. By using density functional theory and Boltzmann transport theory, the electronic structure and thermoelectric properties of carbon doped GaN were studied. The band structure, electronic density of states and thermoelectric properties were calculated. Comparing with the intrinsic bulk-GaN, (1) It was found that the Fermi level moves down, and the band gap becomes narrow for GaN with CN point defects. (2) Power factors become decrease, while thermal conductivity decreases more significantly. Therefore, electrical thermoelectric figure of merit (ZTe) increases, especially, the ZTe increase up to 1.150 at 500 K for GaN with CN point defects. The research could provide reference for experimental studies of GaN-based materials.