矽酸鋅膠體製程與發光特性之研究

本研究是藉由溶膠-凝膠法製備矽酸鋅（Zn2SiO4）螢光膠體，並探討不同的溶液濃度、摻雜劑量及熱處理條件對矽酸鋅螢光膠體之結構、微結構、及光電性質之影響。實驗製程方面，分別是以金屬無機鹽類及金屬有機化合物為起始材料，並摻雜不同劑量的錳、鋁及鈦，並實施共摻雜，製備矽酸鋅螢光膠體。實驗發現，不同的水濃度、以及摻雜劑的劑量，均可形成清澈的溶膠與凝膠，且對於膠化速率有明顯的影響，膠化速率會隨著水含量的減少及摻雜劑濃度的增加而變快。改變溶液濃度及不同的活化劑劑量對於膠體的結晶性，由X-光繞射分析與紅外線光譜顯示並無明顯之影響。經乾燥後的膠體於700˚C熱處理開始形成β-Zn2SiO4 ，而經900˚C熱處理均可形成α-Zn2SiO4結構，隨著熱處理溫度增加，結晶性有增強的趨勢，經900∼1200˚C熱處理後之晶粒大小約為21∼39 nm。掺雜錳、鋁及鈦之膠體，其放射波長分別為為520 nm(綠光)、398∼422 nm(藍紫光)及397~421 nm(藍紫光)，且隨著摻雜量增加，其放射波長有紅移現象發生。共摻雜之膠體，可同時於藍紫光與綠光之波段有一明顯之放射峰。且熱處理溫度與摻雜劑量均會顯著影響膠體的發光強度，隨著熱處溫度升高，及還原氣氛熱處理後，其發光強度均有明顯增強。

關鍵字

矽酸鋅；溶膠-凝膠法；螢光

並列摘要

In this study, nanocrystalline zinc silicate（Zn2SiO4）phosphor xerogels were prepared by the sol-gel process. The effects of solution concentration, doped amount, and heating treatment on the phosphor structure, crystallity, microstructure, and luminescent properties of Zn2SiO4 xerogels were investigated. Homogeneous zinc silicate phosphors were prepared by sol-gel processes using metal salts and metal organic compound as the precursors and doping with Mn, Al, Ti . Transparent sols can be obtained from proper concentrations of water and doped amounts, which also had a significant influence on the gelation rate. The gelation rates accelerated with decreasing water amount, but reduced with increasing dopant amount. However, X-ray diffraction and irfrared spectra showed that the solution concent and dopant amount had no apparent influences on the crystallity. The xerogel formed β-Zn2SiO4 structure after heat-treatment at 700˚C, and α-Zn2SiO4 phase was obtained after firing at 900˚C. With the increase of heating temperature, the crystallinity and grain size increased obvious. After heating at 900∼1200˚C, the average grain sizes were 21∼39 nm. The photoluminescence (PL) spectra showed the peak wavelengths of the green and blue-purple emission at 520 nm, 398∼422 nm and 397~421 nm for doped-Zn2SiO4, respectively. With the increase of doped amounts in Zn2SiO4, the emission peak has a red shift. The wavelength ranges of the blue-purple and green emission were obtained at the same time via the co-doped process. Moreover, the heating temperature and dopant amount had a influence on the luminescent intensity of phosphor powders. With the rise of heating temperature and heating in reduce atmosphere, the luminescent intensity increase.