臺灣博碩士論文加值系統

顯示技術自古至今一直是人類認為的重要技術，顯示器一開始為陰極射線管(CRT)，後續被液晶顯示器(LCD)取代，然後近年來逐漸被發光二極體(LED)所取代。而適用於LED作為背光源的材料為半導體量子點(QD)，因QD具有窄半高寬、顏色可調性佳等優點。目前市面上較為常見的量子點為CdSe，但是因Cd為具有毒性的材料，因此，本研究選擇無毒的InP QD作為研究材料，但是 InP QD本身具有低量子效率(QY)及較為寬廣的半高寬等缺點。
因此，本研究透過一鍋注入法製備ZnInP/ZnS量子點，並使用InCl3和ZnI2/ZnBr2 中的In3+ 和Zn2+ 作為陽離子，六甲基磷三胺（HMPT）中的P3- 作為陰離子用於InP及ZnInP核心的成核及成長。結果顯示，InP核心量子點的放射波長及量子效率分別為518 nm及1 %，而反應溫度為220 °C時，將ZnS殼層包覆360 min後(ZnI2 及ZnBr2 作為Zn2+ 前驅物、十二烷硫醇(DDT)作為S2- 前驅物)，ZnInP/ZnS QD的放射波長從518 nm明顯藍移至499 nm，而QY最高可達113 %，但是因放射波長的半高寬為70 nm較為寬廣不適合應用於顯示器，所以後續則選擇減少核心生長的反應時間，使半高寬可從70 nm縮減到37 nm。因此，從以上可以得知InP的QY可透過ZnS外殼包覆而有所提升，而半高寬可透過減少核心生長的反應時間窄化。而將窄峰樣品與窄峰的紅色螢光粉混合封裝成白光LED元件後，可使NTSC色域面積從原始的90 % 提升到103 %。從結果中可知，ZnInP/ZnS QD量子效率的提升取決於鋅的比例，而在合成中相同條件下，鋅含量越多量子效率可提升越多，但是在較高的鋅濃度條件下，會導致放射波長較短。

In display technology, it is the important role in human since the past until nowadays. Because a picture can represent more than a thousand words. The displays started from cathode ray tube (CRT) and were replaced by liquid crystal displays (LCDs), and then replaced by light emitting diode (LED). The material which is suitable for LED as backlight source, is quantum dots (QDs). They can provide many advantages, such as a narrow emission band width, tunable the emission wavelength. However, most popular used CdSe QDs is toxicity materials. The alternative materials were studied, the best candidate is InP QDs. The drawbacks of InP QD is the low quantum yield (QY) and larger bandwidth.
This work, we synthesized ZnInP/ZnS QDs by one pot injection method, and using In3+ and Zn2+ from InCl3 and ZnI2/ZnBr2 as cation metals and P3- from hexamethylphosphorus triamine (HMPT) as the anion metals for nucleation and growth InP and ZnInP core. The result shows that the InP core QDs exhibit the wavelength of 518 nm and the QY of 1 % and then overcoating ZnS shell (ZnI2 and ZnBr2 as Zn2+ precursor and dodecanethiol (DDT) as S2- precursor) with react at 220 oC for 360 mins, ZnInP/ZnS QDs have the emission wavelength significantly blue shift from 518 to 499 nm with the increasing maximum related QY of 113 %. However, the bandwidth of sample is 70 nm, which is not suitable for display application. Thus, we reduce the core growth reaction time and the emission band width can be reduce from 70 nm to 37 nm. Thus, the low QY of InP can be solved by ZnS shell coating, while the larger bandwidth can be solved by reduce the core growth reaction time. From this result, it can rise the NTSC of device from 90 % to 103 %. The improvement the QY of ZnInP/ZnS QDs depend on the zinc proportion. At the same condition in ZnInP/ZnS QDs synthesis, more proportion of zinc can provide the higher QY. However, the concentration of zinc also a disadvantage. At the higher zinc concentration condition, it provides the lower emission wavelength.

Abstract...i
摘要...iii
Acknowledgments...v
List of Contents...vi
List of Tables...viii
List of Figures...ix
Chapter I Introduction...1
1.1 The evolution of the display...1
1.2 Liquid crystal display...4
Chapter II Literature Review...7
2.1 Quantum dots...7
2.2 Quantum dots for display application...10
2.3 III-V Quantum dots...12
2.4 Mechanism of InP/ZnS quantum dots...13
Chapter III Experimental...17
3.1 Chemicals...17
3.2 InP/ZnS core/shell QDs synthesis...21
3.2.1 InP core synthesis...21
3.2.3 ZnInP/ZnS core/shell QDs synthesis...25
3.3 Device fabrication...27
3.4 Characterization of QDs...27
3.4.1 Ultraviolet-visible absorption spectroscopy (UV-vis)...27
3.4.2 Fluorescence spectroscopy (FL)...27
3.4.3 Transmission electron microscopy (TEM)...27
3.4.4 Quantum yield (QY) measurement...28
3.5 Characterization of performance devices...28
Chapter IV Results and Discussion...31
4.1 InP core QDs...31
4.2 ZnInP core QDs...38
4.3 ZnInP/ZnS QDs...48
4.4 WLED devices...59
Chapter V Conclusion...65
References...66
Extend Abstract...73

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