Ultraviolet ZnO Nanorod/P-GaN-Heterostructured Light-Emitting Diodes

Both i-ZnO and n-ZnO : In nanorod arrays were grown on a p-GaN layer with an anodic alumina membrane template using a vapor cooling condensation method. Electroluminescence emissions were observed from the resulting p-n (p-GaN/n-ZnO : In nanorod array) and p-i-n (p-GaN/i-ZnO nanorod array/n-ZnO : In nanorod array) heterostructured light-emitting diodes (LEDs). The ultraviolet emission peak at 386 nm observed in the p-i-n heterostructured LEDs was attributed to radiative recombination of the near-band edge in the i-ZnO nanorods. Using power-law fitted current-voltage relationships, it was shown that a space-charge-limited current and associated effects occurred in the p-n and p-i-n nanorod heterostructured LEDs.