First-principles simulations of two dimensional electron gas near the interface of ZnO/GaN (0001) superlattice

• We predict the 2DEG near the ZnO/GaN (0001) interface.
• GGA + U method yields precise band gaps for ZnO and GaN.
• Calculated band offsets between ZnO/GaN consist with the experiments.

By applying the on-site Coulomb interaction corrections on the anion:2p and the cation:3d electrons, we find that the GGA + U approach can completely compensate the underestimation of band gap of ZnO and GaN, two wide band gap semiconductors. Based on such approach, we investigate the electronic structure of ZnO/GaN (0001) heterostructure, particularly for the two dimensional electron gas formed near the polar interface. The polarization difference between ZnO and GaN induces the surface charge, resulting in the accumulation of band electrons on the N-polar interface.