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收集所有交通大學研究人員與學生個人或團體所發表之各項學術著作，涵蓋期刊論文、教師專書、學位論文等項。;;Collections of Publications of NCTU Researchers and Students Like Journal Papers and Thesis.

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The Photothermal Stability Study of Quantum Dots Embedded in Sodium Chlorides
(2020-01-01)
Huang, Yu-Ming
;
Hsu, Shun-Chieh
;
Li, Ning
;
Yu, Chung-Ping
;
Ke, Li-Ann
An efficient and useful method for the incorporation of colloidal quantum dots (QDs) into ionic matrices is demonstrated. We prepared three different synthesis methods, which are traditional saturated-salt water, methanol-assisted, and ethanol-assisted methods. The continuous thermal and photonic stress tests indicate that the high temperature, instead of photonic excitation stress, is more detrimental to the illumination capability of the quantum dots. While the traditional saturated-salt water synthesis and methanol-assisted method are quite effective in low temperature and low photon excitation intensity, the quantum dots sealed by the ethanol-assisted method cannot hold under all conditions. An over-1000-h aging test can provide crucial information for the longevity of these quantum dots, and more than 10,000 h of lifetime can be expected.
Highly Efficient and Stable White Light-Emitting Diodes Using Perovskite Quantum Dot Paper
(1970-01-01)
Kong, Chieh-Yu
;
Lin, Chun-Ho
;
Lin, Chih-Hao
;
Li, Ting-You
;
Chen, Sung-Wen Huang
Perovskite quantum dots (PQDs) are a competitive candidate for next-generation display technologies as a result of their superior photoluminescence, narrow emission, high quantum yield, and color tunability. However, due to poor thermal resistance and instability under high energy radiation, most PQD-based white light-emitting diodes (LEDs) show only modest luminous efficiency of approximate to 50 lm W-1 and a short lifetime of <100 h. In this study, by incorporating cellulose nanocrystals, a new type of QD film is fabricated: CH3NH3PbBr3 PQD paper that features 91% optical absorption, intense green light emission (518 nm), and excellent stability attributed to the complexation effect between the nanocellulose and PQDs. The PQD paper is combined with red K2SiF6:Mn4(+) phosphor and blue GaN LED chips to fabricate a high-performance white LED demonstrating ultrahigh luminous efficiency (124 lm W-1), wide color gamut (123% of National Television System Committee), and long operation lifetime (240 h), which paves the way for advanced lighting technology.
Synthesis of Terpyridine Ligands and Their Complexation with Zn2+ and Ru2+ for Optoelectronic Applications
(2008-12-01)
Vellis, Panagiotis D.
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Mikroyannidis, John A.
;
Lo, Chih-Nan
;
Hsu, Chain-Shu
;
應用化學系
A series of soluble conjugated ligands TT, FT, PT, and NT that contained terpyridyl terminal units were synthesized by Heck coupling. These ligands absorbed at 341-434 nm and emitted blue-green light, with maximum at 440-522 nm and photoluminescence quantum yields of 0.15-0.71 in solution. The double-layer electroluminescent devices with the configuration of ITO/PEDOT/ligand FT, PT, or NT/Ca/Al exhibited a brightness of 43-63 cd/m(2). These ligands were further reacted with zinc(II) and ruthenium(II) ions and subsequent anion exchange to afford linear and supramolecular complexes. The photophysics of these complexes were investigated. A significant redshift of the emission maximum of the Zn complexes relative to the corresponding ligands was observed. The Ru complexes were used to fabricate photovoltaic devices with the structure ITO/PEDOT/Ru complex/P3HT:PCBM (1:1 wt/wt)/Ca/Al. The power conversion efficiency of these polymer-fullerene bulk heterojunction photovoltaic devices was up to 0.71%. (C) 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46:7702-7712,2008
Multi-Azimuth Failure Mechanisms in Phosphor-Coated White LEDs by Current Aging Stresses
(2018-04-01)
Peng, Zhangbao
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Guo, Ziquan
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Wu, Tingzhu
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Zhuang, Peng
;
Ye, Zhicheng
We have experimentally analyzed multi-azimuth degradation mechanisms that govern failures of commercially-available high-power (1 Watt) phosphor-coated white (hppc-W) light-emitting diodes (LEDs) covered with peanut-shaped lenses under three current-stress aging (CSA) conditions. Comprehensive analyses focus on photometric, chromatic, electrical, thermal and packaging characteristics. At the packaging level, (a) the decrease of the phosphor-conversion efficiency; (b) the yellow-browning of the optical lens; and (c) the darkening of the silver-coated reflective layer deposited with extraneous chemical elements (e. g., C, O, Si, Mg, and Cu, respectively) contribute collectively to the integral degradation of the optical power. By contrast, Ohmic contacts, thermal properties, and angles of maximum intensity remain unchanged after 3840 h aging in three cases. Particularly at the chip level, the formation of point defects increases the number of non-radiative recombination centers, and thus decreases the optical power during aging stages. Nevertheless, in view of the change of the ideality factor, the Mg dopant activation and the annealing effect facilitate the increase of the optical power in two specific aging stages (192 h similar to 384 h and 768 h similar to 1536 h). This work offers a systematic guidance for the development of reliable LED-based light sources in general-lighting areas.
Development and Fabrication of AlGaInP-Based Flip-Chip Micro-LEDs
(2018-01-01)
Horng, Ray-Hua
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Chien, Huan-Yu
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Chen, Ken-Yen
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Tseng, Wei-Yu
;
Tsai, Yu-Ting
The fabrication of AlGaInP-based flip-chip micro light-emitting-diodes (LED; emitting area: 4.5 mil x 5 mil) with horizontal electrodes is reported in this paper. The thickness of the epitaxial layer of the thin LED structure was reduced to 50% of that of the traditional thick LED, whereas carrier concentration in the n-type GaAs contact layer was increased to 5 x 10(18) cm(-3) to meet the Ohmic contact requirement. At a current injection of 5 mA, the thin LED exhibited a forward voltage, output power, and external quantum efficiency of 1.8 V, 1.9 mW, and 19%, respectively. The optoelectronic performance of the thin LED was as good as that of the traditional thick red LED. The technique proposed by this paper can be used to integrate AlGaInP-based LEDs with nitride LEDs for full-color display applications.
具晶圓級封裝技術之高內部量子效率與低效率下降率之氮化鎵發光二極體開發計畫( I )
(2011)
郭浩中
;
Kuo Hao-Chung
;
國立交通大學光電工程學系（所）
由於石油價格高漲及石化原料燃燒造成的溫室效應，如何更有效率的使用有限的能源是目前最重要、最熱門的研究方向。目前在能源的使用上，先進國家在照明上的能源使用比例都約在20%以上，因此，若是能夠使用更高效率的照明燈具，對節能減碳的實現，有非常顯著的幫助。本整合型計畫將以實現高效率的LED 照明系統為主，結合來自交大、成大和台南大學三所大學共七位教授共同合作，針對整個氮化鎵發光二極體從磊晶、製程到封裝分成三個子計畫進行完整系統性的研究。在子計畫一的磊晶研發方面，將結合交大和成功大學磊晶設備的資源，在奈米級結構上利用HVPE 和MOCVD 等磊晶設備進行再磊晶，提升磊晶品質同時減少GaN LED 效率在高注入下極具降低的情形。在子計畫二的元件製作上，本計畫針對高散熱、高萃取效率的垂直式發光二極體進行研究，其中包括薄膜式、覆晶式和整合HVPE 的新式樣元件結構等。除元件本身製程技術的改進外，由於垂直式GaN LED 相較於傳統的元件結構更容易進行晶圓級製程的整合，因此本整合計畫第三個子計畫便是將垂直式GaN LED 元件與矽基板整合進行晶圓級封裝，導入螢光粉塗佈、晶圓接合，發展低成本的晶圓對晶圓封裝技術。藉由本整合計畫的整合和發展，將能夠發展出一個高效率、低成本的LED 照明系統。

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