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 6.68×1017cm−3 and a Si-doped n-GaN film with an electron concentration of 1.1×1018cm−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.