Forward- and reverse-biased electroluminescence behavior of chemically fabricated ZnO nanotubes/GaN interface

摘要

Electroluminescence characteristics of an n-ZnO nanotubes/p-GaN heterostructure light-emitting diode (LED) have been investigated at forward and reverse bias. Distinctly different emission spectra have been observed and the location of the recombination of electron-hole is analyzed under both configurations. The forward-biased emission spectrum shows two peaks centered at around 450 and 560 nm, while the reverse-biased spectrum exhibits a single emission peak at 650 nm. By comparing the current transport mechanisms, it is suggested that the violet-blue emission peak (450 nm) observed only under forward bias is originating from the heterojunction of the ZnO nanotubes/p-GaN LED. The influence on the emission intensity of the device with the increase in temperature at constant current is studied in the range from 25 to 65 °C, to check its compatibility for practical applications and under harsh conditions. (Some figures in this article are in colour only in the electronic version)