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 $6.68\times {10}^{17}{\mathrm{cm}}^{-3}$ and a Si-doped $n$ -GaN film with an electron concentration of $1.1\times {10}^{18}{\mathrm{cm}}^{-3}$ . The $I\text{–}V$ 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.