p -ZnO/ n -GaN heterostructure ZnO light-emitting diodes

We report on the characteristics of a ZnO light-emitting diode (LED) comprised of a heterostructure of p -ZnO/ n -GaN. The LED structure consisted of a phosphorus doped p -ZnO film with a hole concentration of 6.68 × 10 17 cm − 3 and a Si-doped n -GaN film with an electron concentration of 1.1 × 10 18 cm − 3 . The I - V of the LED showed a threshold voltage of 5.4 V and an electroluminescence (EL) emission of 409 nm at room temperature. The EL emission peak at 409 nm was attributed to the band gap of p -ZnO which was reduced as the result of the band offset at the interface of p -ZnO and n -GaN.