- 學位論文
Ba3MgSi2O8鹼土矽酸鹽螢光粉之合成與發光特性研究
Synthesis and Luminescent Properties of Ba3MgSi2O8 Phosphors
摘要
本研究旨在探討新型鹼土矽酸鹽系螢光粉的製備與發光特性。利用傳統高溫固態反應法製備摻雜不同稀土元素及過渡金屬活化之Ba3MgSi2O8螢光粉體，製作Ba3MgSi2O8主體晶格時，討論添加不同助熔劑、不同添加濃度、不同合成溫度對Ba3MgSi2O8主體晶格合成影響，另外於摻雜激活劑時，觀察煆燒溫度、反應氣氛、摻雜離子濃度等實驗參數對其發光性質的影響，最後嘗試利用網版印刷的方式將做好的Ba3MgSi2O8螢光粉製作成電激發光元件。 實驗結果顯示添加2wt% H3BO3助熔劑並在燒成溫度1250℃下，可以合成出完整的Ba3MgSi2O8主體晶格並具有良好的發光強度。放射光譜量測結果顯示，Ba3MgSi2O8:Eu3+螢光粉的放射峰來自5D0→7FJ(J=1,2,3,4)躍遷，且放射光譜形狀不受主體晶格改變的影響，皆呈現橘紅光放射；Ba3MgSi2O8:Eu2+螢光粉的放射光譜以4f65d→8S7/2的躍遷為主，但峰值位置受到主體晶格的共價性與晶體場分裂效應影響，放出極強442nm的藍光；Ba3MgSi2O8:Eu2+,Dy3+因有增感劑的作用而提升發光強度；Ba3MgSi2O8:Eu2+,Mn2+可以放射白光，並依摻雜濃度調配不同顏色的光。 EL結果顯示具有發光強度，並且可用在特殊需要場合。根據激發光譜及UV-vis分析，Ba3MgSi2O8摻雜Eu3+，Eu2+，Mn2+，Dy3+的激發波段均位於紫外光區域。因其具有高亮度故在以紫外光晶片激發的白光LED領域上具有應用潛力。
並列摘要
This study is focused on the synthesis and luminescent properties of novel alkaline silicate phosphors. Conventional solid state reaction method is adopted to synthesize earth element-activated phosphors and co-doping phosphors. To synthesize Ba3MgSi2O8 host, we discuss the effect of different flux, flux concentration, firing temperture.In doping process the effect of different firing temperture, doping concentration and atmosphere on the luminescent properties is observed.Finally we try to make a EL device with Ba3MgSi2O8 phosphor we made. When we add 2wt% of H3BO3 and fireing temperture 1250°C, we will have Ba3MgSi2O8 with good emission property.The emission peaks of Ba3MgSi2O8:Eu3+ phosphor is originated from 5D0→7FJ(J=1,2,3,4) transitions, which show a orange-red color and are also independent of host lattice surroundings. And Ba3MgSi2O8:Eu2+phosphors show a 4f65d→8S7/2 transition with blue 442nm emission, which depends on the covalence and crystal field splitting effects of the host lattice.Due to sensitizer, Ba3MgSi2O8:Eu2+,Dy3+ have better emission intensity and long afterglow property. Ba3MgSi2O8:Eu2+,Mn2+ will show white color and show different color with different doping concentration. The EL device show emission intensity and we can use it in special situation.Based on excitation spectra analysis and UV-vis analysis ,the main excitation peaks of Ba3MgSi2O8:Eu3+ ,Ba3MgSi2O8:Eu2+ , Ba3MgSi2O8:Eu2+,Dy3+ and Ba3MgSi2O8:Eu2+,Mn2+ phosphors are located at ultraviolet region of the spectrum. Due to its high emission intensity, these phosphors possess potentials on UV-chip excited WLED applications.