Room temperature electroluminescence from the n-ZnMgO/ZnO/p-ZnMgO heterojunction device grown by ultrasonic spray pyrolysis

The heterojunction light-emitting diode with n-Zn0.8Mg0.20/ZnO/p-Zn0.8Mg0.20 structure was grown on single-crystal GaAs(I 0 0) substrate by a simple process of ultrasonic spray pyrolysis. The p-type Zn0.8Mg0.20 layer was obtained by N-In codoping. A distinct visible electroluminescence with a dominant emission peak centered at similar to 450 nm was observed at room temperature from the heterojunction structure under forward bias conditions. The origin of electroluminescence emission was supposed to be attributed to a radiative recombination through deep-level defects in the ZnO active layer. The result reported here provides convincing evidence that ZnO based light-emitting devices can be realized at extremely low cost. (c) 2006 Elsevier B.V. All rights reserved.