ABSTRACT
This chapter discusses on the current achievement to overcome the difficulties for the realization of zinc oxide (ZnO) ultraviolet (UV) laser diodes. ZnO has been recognized to be a promising candidate for the fabrication of low-cost UV optoelectronic devices. In addition, due to the conductive nature of ZnO, it has the potential to be used as the semiconductor materials for making of inexpensive UV optoelectronic devices such as UV laser diodes. In addition, the difficulty to form cleaved facets in ZnO material can be replaced by using random cavities to support coherent optical feedback inside ZnO medium. The proposed heterojunction can achieve high optical gain under electrical excitation as well as obtain sufficient optical feedback from the laser medium to sustain lasing oscillation. The emergence of sharp peaks, which are attributed to coherent random lasing action, is due to the presence of stripe patterns to allow the formation of closed-loop random cavities.
