Figure 1From: The origin of the red emission in n-ZnO nanotubes/p-GaN white light emitting diodes SEM image of ZnO nanotubes on p-GaN substrate. (a) before annealing, (b) after annealing, (c) typical I-V characteristics for the fabricated LEDs, and (d) The schematic illustration of the fabricated LEDs.Back to article page