Study of electronic properties on the n-GaN (0001) surface with points defects

The influence of defects on the surface of the semiconductor is irreversible. The influence of intrinsic point defects on the electronic properties of n-doped GaN (0001) surface is studied based on the first principles. The results show that, the N interstitial defect (N_i) and Ga Vacancy (V_Ga) are the more easily formed in the case of Si doping. The defect level generated by an appropriate amount of defects contributes to the transition of electrons, thereby improving the n-type conductivity characteristics. In particular, the Ga vacancy makes the work function drop significantly, which promotes the emission of electrons. However, once the defects inside the material exceed a certain level, any defects will play a counterproductive role. This paper could provide some guidance for the preparation of n-GaN optoelectronic devices.