臺灣博碩士論文加值系統

隨著時代進步，顯示器在日常生活已是不可或缺，但常見的冷陰極射線管(CCFL)作為背光源時對比度不佳，僅佔NTSC的74 %。伴隨著白光發光二極體(WLED)的發展，藍光晶片激發黃光螢光粉(YAG)取代CCFL作為背光源，但YAG的放射峰與彩色濾光片不匹配，僅能夠達到71 % NTSC色域面積。為了達到更飽和的色彩，出現以綠、紅螢光粉混和透過藍光晶片激發的WLED。雙色螢光粉的放射峰相對於YAG能夠與彩色濾光片有較好的匹配程度。但是螢光粉半高寬過寬，僅能提升色域面積至85 %。為了解決此問題，量子點的窄半高寬與波長可調性取代螢光粉，成為新一代顯示器背光源之材料，其中以鎘(Cd)基量子點的研究最為廣泛。
本研究分為兩個部分，第一部分為紅、綠三元合金化ZnCdSe量子點之製備與各項物性分析。將綠光(510、520與530±5 nm)與紅光(615±5 nm)混和，透過藍光晶片激發獲得白光，以市售濾光片分析色域面積。在QD510-40LED10時，能夠得到白光元件，效率為2.15 lm/W，並且涵蓋103與147 %的NTSC與sRGB色域面積為最佳結果。第二部分為以Stöber法在表面生長二氧化矽。選用綠光波長511 nm、效率50 %與紅光波長609 nm、效率30 %之量子點進行SiO2包覆。包覆後SiO2-G, SiO2-R效率分別下降至10與3 %。此外，GQD加熱100 oC持溫3小時後淬滅，而SiO2-G加熱66小時後，效率下降75 %，熱穩定性明顯提升。元件QD/SiO2-18LED84之色度座標、效率、NTSC與sRGB色域面積分別為(0.35, 0.33)、0.1 lm/W、102 %與146 %。

With the progress of the times, displays have become indispensable in daily life. However, cold cathode fluorescent lamp (CCFL) have poor contrast as backlight sources, and the color gamut is only 74 % of NTSC. With the development of white light-emitting diodes (WLEDs), Y3Al5O12 (YAG) phosphor-based WLEDs instead of CCFL as the backlight, but its emission spectrum does not match the color filters resulting in only 71 % NTSC color gamut can be reached. In order to achieving a more saturated color, three emission wavelength WLED, which is composed green and red phosphors and blue LED was developed. The emission peak of the two-color phosphors has a better matching degree with the color filter than that of the YAG. However, the full width at half maximum (FWHM) of phosphor is too wide, resulting in the color gamut only reach to 85 % of NTSC. In order to solve this problem, the small FWHM and wavelength tunability of quantum dots (QDs) replace the phosphor as the new generation backlight material. Among them, the cadmium-based QDs are the most widely studied.
This study is divided into two parts for discussion. The first part is the preparation and characterization of ternary ZnCdSe monochromatic light QDs. Green QDs (510, 520 and 530±5 nm) is mixed with red QDs (615±5 nm) and excited by blue LED to form WLED. The color gamut of WLED was analyzed by color filters. The luminous efficacy of QD510-40LED10 is 2.15 lm/W, and 103 % NTSC and 147 % sRGB color gamut can be obtained.
In the second part, a Stöber coating method was used to form a layer of silica on QDs surface. Choosing green QDs (511 nm, QY of 50 %) and red QDs (609 nm, QY of 30 %) to coating with silica. After coating, the QYs of SiO2-G and SiO2-R drop to 10 and 3 %, respectively. For SiO2-G, the QY decreases 75 % after heating for 66 hours, while the uncoated QDs is quenched after 3 hours. The chromaticity coordinates, luminous efficacy, NTSC and sRGB of QD/SiO2-18LED84 is (0.35, 0.33), 0.1 lm/W, 102 % and 146%.

摘要.......................................................................i
Abstract.................................................................iii
誌謝......................................................................iv
目錄.......................................................................v
表目錄..................................................................viii
圖目錄....................................................................ix
第一章 前言...............................................................1
1.1 LED發展史..............................................................1
1.2應用於背光源之白光LED.....................................................1
第二章 文獻回顧.............................................................4
2.1 顯示器規範..............................................................4
2.2影響背光源條件...........................................................7
2.3量子點.................................................................13
2.3.1鎘基量子點............................................................13
2.3.2量子點表面改質........................................................22
2.4 研究動機與目的.........................................................27
第三章 實驗方法與步驟....................................................28
3.1 實驗藥品..............................................................28
3.2 ZnCdSe量子點之製備....................................................30
3.2.1 紅、綠單色光量子點製備...............................................30
3.2.2量子點純化...........................................................30
3.2.3二氧化矽包覆量子點....................................................33
3.3 LED元件封裝...........................................................35
3.4 ZnCdSe量子點與LED元件之特性分析........................................37
第四章 結果與討論.........................................................39
4.1 ZnCdSe三元量子點之合成.................................................39
4.1.1綠光量子點(GQD)物性分析...............................................39
4.1.2紅光量子點物性分析....................................................44
4.2元件封裝...............................................................49
4.2.1紅綠量子點混和之元件封裝..............................................49
4.2.2 QD-LED元件分析......................................................53
4.3 二氧化矽包覆量子點.................................................67
4.3.1二氧化矽包覆量子點之物性分析...........................................67
4.3.2 QD/SiO2-LED元件分析.................................................76
第五章 結論..............................................................84
參考文獻..................................................................85
Extended Abstract........................................................90

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