Near-ultraviolet electroluminescence from ZnO-based light-emitting diodes with n-ZnO nanorod/p-GaN direct-bonding heterojunction structure

We demonstrate the fabrication and characterization of ZnO nanorods (NRs)/GaN-based heterojunction direct-bonding light-emitting diodes (LEDs) by using Al-doped ZnO (AZO) conductive glass acting as a substrate for the first time. Under the forward bias, the n-ZnO/p-GaN heterojunction can display a pure near-ultraviolet electroluminescence (EL) emission located at 390 nm, while the deep-level (DL) emission had been almost totally suppressed. The EL origination and corresponding carrier transport mechanisms were investigated qualitatively according to PL results and energy band diagram.