Design and fabrication of ultraviolet metal-oxide light-emitting devices

Abstract

Zinc Oxide (ZnO) has a wide bandgap energy (~3.37 eV) and high exciton binding enegy (~ 60 meV) which is more than two times larger than that of Gallium Nitride (GaN). Therefore, ZnO has been recognized as a promising candidate of ultraviolet (UV) optoelectronic devices operating at room temperature or even at high temperature. Especially, the high exciton binding energy favors the excitonic stimulated emission in the application of lasers. However, ZnO has a wurtzite crystal structure, and thus two sufficiently smooth mirror surfaces are hardly to be cleaved to form Fabry-Perot cavity. The discovery and development of ZnO random laser successfully avoid this difficulty by forming the lasing resonance via multi-scattering in a closed-loop feedback.