9:30 AM - 11:30 AM
[16a-P3-31] Optical properties of zinc oxide particles attached with surface modified groups
Keywords:zinc oxide, surface modification, size effect
Zinc oxide is a wide band gap 3.4 eV semiconductor, having high exciton binding energy of 60 meV; it is used as ultraviolet light emitters. On the other hand, zinc oxide particles are widely used as safety white pigment for baby powder. Zinc oxide has a potential to use as light emitter for medical field. In this study, ZnO nanoparticles were prepared by a precipitation method. Their emission properties and their particle sizes were investigated. From the TEM observation, the particle sizes were 20 - 50 nm, and the crystal structure was a wurtzite. Photo emission measurements were performed on suspensions in EtOH of ZnO nanoparticles of different particle sizes irradiated by 310 nm light. All suspensions show two emission bands. One is a sharp exciton emission band, whose peak wavelength increased with the increase of the particle sizes. The other is a broad emission band in the visible part of the spectrum. A shift value of the peak wavelength with the particle size dose not clear compared with the exciton emission; the intensity of the emission depends on the particle size.