Disorder and Raman scattering in reactively sputtered ZnO
謝 至中1*, 何易恒1, 林昀蔚1, 黃于真1, 陳俏蒙1, 黃玉林*2
1物理系應用物理碩士班, 國立東華大學, Hualien, Taiwan
2物理學系, 國立東華大學, Hualien, Taiwan
* presenting author:謝至中, email:chun060690@hotmail.com
Zinc oxide (ZnO) is a polar semiconductor having a wide direct bandgap Eg=3.37eV at room temperature. The exciton binding energy as high as 60meV and strong electron-phonon interaction lead to advantageous optical and optoelectronic properties, making ZnO a highly attractive candidate material for developing novel photonic devices. Recent researches showed that formation of mesoscopic structures provides possibilities of tuning the intrinsic optoelectronic properties based on confined carries and phonons and/or their interactions. In this study, ZnO nanocrystalline films were grown by reactive sputtering followed by thermal anneals. Effects of disorder on lattice vibrations, excitonic behaviors as well as their coupling have been investigated based on structural characterizations and observations of photoluminescence and Raman scattering. Spectral shifts and lineshape variations observed in the Raman and photoluminescence spectra will be discussed in relation to quantum confinement and electronic coupling of the longitudinal optical phonon modes.

Keywords: Raman scattering, photoluminescence, electron-phonon coupling, ZnO