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Keywords:

  • GaN;
  • heterojunctions;
  • light-emitting diodes;
  • nanorods;
  • solution deposition;
  • ZnO

Abstract

Zinc oxide (ZnO) is a wide-bandgap material with excellent optical properties for optoelectronics applications. ZnO nanostructures are attractive for research because it is easy to fabricate in single-crystalline form and it has interesting physical properties at the nanoscale. In this paper, we report our successful growth of a p-type ZnO nanorods/n-GaN film heterojunction ultraviolet light-emitting diode (LED). The heterojunction LED shows its advantages over a p-ZnO film/n-GaN film heterojunction. The LED demonstrates a rectifying IV characteristics with a turn-on voltage of 2.7 V. The ideality factor is 6.5. The existences of interface charges in the interface are the reason for this low turn-on voltage and high ideality factor in the heterojunction. Electroluminescence (EL) spectra of the LED consist of an ultraviolet peak at 378 nm and a broad yellow emission centered at 560 nm. Fitting and comparing EL of the LED with PL of p-ZnO and n-GaN show that p-ZnO contributes more to the EL than n-GaN.