Product Code: ICAL05_M701

Laser Synthesis of Aligned ZnO Nano Crystals for Large Area UV Emitter (Keynote Presentation)
Authors:
Tatsuo Okada, Kyushu University; Hakozaki, Fukuoka Japan
Presented at ICALEO 2005

Zinc oxide (ZnO) is one of the most promising material suitable for generating ultraviolet (UV) light. UV stimulated emission from optically-pumped nano-wire-array has been reported by many research groups. Recently it has been reported that nano-structured ZnO crystals also show the good field emission characteristics. A various method has been applied to grow ZnO crystals. We have succeeded in growing large quantities of ZnO nanorods by a newly developed nano-particle-assisted PLD (NAPLD) without using any catalyst, where nano-particles formed in the gas phase by the condensation of the laser-ablated species are transported on to the substrate to form nanorods. The nano-rod crystals having a hexagonal shape with a pyramidal top were synthesized on a sapphire substrate by a single-step process. We describes the growth mechanism in NAPLD, the lasing and the field emission characteristics of ZnO nano-rod crystals synthesized by NAPLD, The nano-rod crystals act as an efficient ultraviolet emitter showing the stimulated emission under an optical excitation and also act as field emitters These ZnO hexagonal nano-rods with the sharp pyramidal surface can be used for building a large area directional UV emitter using the stimulated emission.