Chapter 4 - ZnO nanostructures and lasers

Abstract

The urgent requirement of ultraviolet (UV) semiconductor laser with low cost and high performance has motivated intensive research in zinc oxide (ZnO) material because of its wide bandgap of 3.37eV and large exciton binding energy of 60meV. Especially, its exciton stability opens numerous opportunities for making low-threshold excitonic lasing operable at room or even higher temperature. Currently, many reports on ZnO based UV lasers, either optically pumped or electrically pumped, have been demonstrated by employing ZnO micro- or nanostructures as the gain media, which are deemed as potentially ideal building blocks for UV lasers owing to its self-formed microcavity structures. This chapter provides a brief overview of the synthesis of ZnO nanostructures, and their fundamental properties for optoelectronic device applications are also investigated. Finally, we reviewed the recent progress on the optically and electrically pumped ZnO nanostructure lasers.