Electroluminescence from ZnO nanowires in n-ZnO film/ZnO nanowire array/p-GaN film heterojunction light-emitting diodes

Abstract
ZnO nanowire-array-embedded n - Zn O ∕ p - Ga N heterojunctionlight-emitting diodes were fabricated by growing Mg-doped p - Ga N films,ZnOnanowire arrays, and polycrystalline n - Zn O films consecutively. Electroluminescence emission having the wavelength of 386 nm was observed under forward bias in the heterojunctiondiodes and the UV-violet light was emerged from the ZnOnanowires. The heterojunctiondiode was thermal treated in hydrogen ambient to increase the electron injection rate from the n - Zn O films into the ZnOnanowires. High concentration of electrons supplied from the n - Zn O films activated the radiative recombination in the ZnOnanowires, i.e., increased the light-emitting efficiency of the heterojunctiondiode.