Figure 3

The room temperature EL spectra of n-ZnO/p-GaN heterojunction LED (a) under various forward biases and (b) under reverse biases. The lighting images under the biases (+36 V and −30 V) are shown in the insets of (a) and (b), respectively. (c) The band diagram of the n-ZnO/p-GaN heterojunction devices under reverse bias. (d) The three light output intensities of the heterostructure as a function of injection current under reverse bias.