ABSTRACT
This chapter focuses on the issues of p-GaN/n-zinc oxide (ZnO) and p-GaN/i-ZnO/n-ZnO heterojunctions and their devices based on ZnO nanostructures. It discusses their basic principle, fabrication methods, and electroluminescence properties. The size effect, defect states, and other perturbations, which may be the result of imperfect crystal lattice matches, are ignored in the Anderson model. The energy band diagram inferred by the Anderson model is drawn to determine the reasons of the improved emission properties of the heterojunction with insertion of an intrinsic ZnO layer. The ZnO nanostructure probably is considered as the most promising one in low-dimension systems due to its large exciton binding energy, high electromechanical coupling constant, and resistivity to harsh environment as well as the relatively easy fabrication process. Lattice mismatch is one of the most important factors for the growth of high-quality films. The reproducibility and light emission efficiency remains to be the main issue.
