新穎矽酸鹽、鈦矽酸鹽及鍺矽酸鹽螢光體溶膠凝膠法合成、發光特性鑑定與固態照明之應用

Abstract

本研究利用溶膠-凝膠合成法成功製備Sr2TiSi2O8:Mn2+、Sr2Ti2Si4O14:Mn2+、BaGe2.5Si1.5O9:Mn4+ 、BaGe2.5Si1.5O9:Eu2+、Ba2TiSi2O8:Eu2+、Ba4La6O(SiO4)6:Eu2+等六種紅光及綠光螢光體，並分別合成與探討Eu2+或Mn2+活化中心摻雜的螢光體。本研究亦利用微波法輔助合成，以縮減繁瑣的溶膠凝膠合成法所需時間，另一方面也利用X光粉末繞射儀、掃描式電子顯微鏡、紫外-可見光光譜儀、螢光光譜儀、熱消光、量子效率與色度座標量測以進行螢光體之晶體結構、發光特性及色度學特性分析鑑定，以期能開發新穎且可應用於白光發光二極體的螢光材料。 本論文第一部分探討不同螢光體之最佳製備條件、X光粉末繞射晶相分析鑑定與主體電子顯微鏡微結構特徵；第二部分探討各種螢光體所摻雜活化劑濃度最適化、發光特性、色度座標、漫反射光譜及熱消光效應；第三部分則利用本研究所製備的螢光體搭配近紫外發光二極體及互補商用螢光粉以封裝白光發光二極體並研究其發光特性、演色性與色溫等效能。其中紅光Sr2TiSi2O8:Mn2+及Sr2Ti2Si4O14:Mn2+螢光體可搭配黃光Ba2SiO4:Eu2+及藍光BAM:Eu2+商品再與380 nm近紫外晶片封裝成白光發光二極體；另外綠色系列的BaGe2.5Si1.5O9:Eu2+、Ba2TiSi2O8:Eu2+、Ba4La6O(SiO4)6:Eu2+螢光體則搭配藍光BAM:Eu2+及紅光Sr2Si5N8:Eu2+商品，再分別與375 nm、365 nm或385 nm近紫外晶片封裝成白光發光二極體。效能分析顯示這五種螢光體應用於白光發光二極體皆可以調控成具有高演色性且可比擬D65標準白光光源。

In this study, we have successfully synthesized several new red-emitting phosphors with compositions of Sr2TiSi2O8:Mn2+, Sr2Ti2Si4O14:Mn2+, BaGe2.5Si1.5O9:Mn4+, and green-emitting phosphors with compositions of BaGe2.5Si1.5O9:Eu2+, Ba2TiSi2O8:Eu2+ and Ba4La6O(SiO4)6:Eu2+ by using PGMS/sol-gel and microwave-assisted synthetic methods, which may shorten the preparation time of tedious sol-gel method. The crystal structure, luminescence, chromaticity properties and thermal luminescence quenching behaviors of the above phosphors were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), photoluminescence (PL) and UV/Vis spectroscopy. The first part of this thesis reports the optimization of synthetic conditions for all novel silicate-derivative phosphors, and analyzing the XRD profiles and SEM images. Secondly, we discuss the optimization of dopant concentration of the activator for various phosphors, luminescence properties, chromaticity coordinates, diffuse reflectance spectroscopy and thermal quenching effect. The last part of this study investigated the use of as-prepared phosphors and complementary commercial phosphors with near UV-LED chips to fabricate white-light LED (WLED) and studied the luminescence characteristics, chromaticity and color temperature performances. The red-emitting Sr2TiSi2O8:Mn2+ and Sr2Ti2Si4O14:Mn2+ phosphors were utilized to fabricate a WLED device with yellow-emitting Ba2SiO4:Eu2+, blue-emitting BAM:Eu2+, and a 380 nm near-UV LED chip. In addition, the green-emitting BaGe2.5Si1.5O9:Eu2+, Ba2TiSi2O8:Eu2+, and Ba4La6O(SiO4)6:Eu2+ phosphors were utilized to fabricate a WLED device with blue-emitting BAM:Eu2+, red-emitting Sr2Si5N8:Eu2+ with corresponding near-UV chips with wavelengths of 365 -385 nm. These results suggest that the new phosphors developed herein are potentially useful for trichromatic WLED application.