A Study on the Synthesis, Microstructures and Luminescent Properties of ZnO Nanoparticles
|關鍵字:||奈米氧化鋅;逆相微乳液;相圖;微乳液;光致發光光譜圖;色度座標;掃瞄式電子顯微鏡;穿透式電子顯微鏡;ZnO nanoparticles;Reverse microemulsion;Phase diagram;Microemulsion;Photoluminescence spectra;Chromaticity coordinates;SEM;TEM|
微乳液法分為正相及逆相微兩類型，本論文分別採用此種配方以合成六方結構奈米氧化鋅微粒，最佳製程條件為350 ℃，燒成3.5小時。雷射粒徑分佈結果顯示，測得的奈米粒子尺寸範圍主要分佈在48~62 nm，平均粒徑為57 nm。而掃瞄式電子顯微鏡顯示，奈米粒子明顯地形成奈米團簇，另一方面，穿透式電子顯微鏡則顯示，大部分奈米粒子尺寸範圍在10~25 nm，最小粒徑尺寸達8~12 nm。
The goal of this research is to investigate the correlations among synthetic conditions, microstructures and luminescence for ZnO nanoparticles derived from microemulsion method. Normal and reverse microemulsion routes were adopted to prepared wurtzite ZnO nanoparticles and the optimal conditions were found to be 350℃ and 3.5 hr. The size of ZnO nanoparticles was found to be in the range of 48-62 nm with average size of 57 nm, as determined by laser light scattering method. On the other hand, the clustering of nanoparticles was apparently observed by SEM and as indicated by TEM micrographs, the size distribution lies in the range of 10-25 nm, which smallest particles obversed in the range of 8-12 nm. Both types of microemulsions with different proportions of surfactants:oli phase:water phase have been adopted to prepare ZnO nanoparticles, which were further characterized by the techniques such as X-ray diffraction (XRD), scanning and transmission electron microscopes (SEM and TEM), photoluminescence (PL) spectra, and CIE coordinates . We also tried to establish the correlation between microemulsion compositions and sizes of ZnO nanoparticles. As indicated by XRD, with decreasing content of oil phase:water phase ratio of the reverse microemulsion system, the FWHM of the strongest diffraction peak (200) was found to decrease and a red shift in emission wavelength (λem) in the visible range of PL spectra was also observed. With the ratio for oil:water content of the microemulsion system approaching the central region of the three-component phase diagram of p-xylene-glycerol-AOT, the size of ZnO nanoparticles was found to become smaller and the correspondingλem was observed to exhibit a blue shift in visible range of the PL spectra.