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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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Intense blue-emitting Ca2PO4Cl:Eu2+ phosphor for near-ultraviolet converting white light-emitting diodes
(2010-12-01)
Chiu, Yi-Chen
;
Liu, Wei-Ren
;
Chang, Chun-Kuei
;
Liao, Cheng-Chun
;
Yeh, Yao-Tsung
A blue phosphor Ca2PO4Cl:Eu2+ (CAP:Eu2+) was synthesized by solid state reaction. The Ca2PO4Cl:Eu2+ exhibited high quantum efficiency and excellent thermal stability. The luminescent intensity of Ca2PO4Cl:Eu2+ was found to be 128% under excitation at 380 nm, 149% under 400 nm, and 247% under 420 nm as high as that of BaMgAl10O17:Eu2+. The optimal doping concentration was observed to 11 mol.% of CAP:Eu2+. The energy transfer between Eu2+ ions in CAP were occurred via electric multipolar interaction, and the critical transfer distance was estimated to be 1.26 nm. A mixture of blue-emitting Ca2PO4Cl:Eu2+, green-emitting (Ba,Sr)(2)SiO4:Eu2+ and red-emitting CaAlSiN3:Eu2+ phosphors were selected in conjunction with 400 nm chip to fabricate white LED devices. The average color-rendering index R-a and correlated color temperature (T-c) of the white LEDs were found to be 93.4 and 4590 K, respectively. The results indicated that it was a promising candidate as a blue-emitting phosphor for the near-UV white light-emitting diodes.
Enhancing the performance of photovoltaic cells by using down-converting KCaGd(PO4)(2):Eu3+ phosphors
(2011-09-01)
Chen, Yen-Chi
;
Huang, Woan-Yu
;
Chen, Teng-Ming
;
應用化學系
;
Department of Applied Chemistry
The goal of this work is aimed to improve the power conversion efficiency of single crystalline silicon-based photovoltaic (PV) cells by using the solar spectral conversion principle, which employed a down-converting phosphor to convert a high-energy ultraviolet photon to the less energetic red-emitting photons to improve the spectral response of Si solar cells. In this study, the surface of silicon solar cells was coated with a red-emitting KCaGd(PO4)(2):Eu3+ phosphor by using the screen-printing technique. In addition to the investigation on the microstructure using scanning electron microscopy (SEM), we measured the short circuit current (I-sc), open circuit voltage (V-oc), and power conversion efficiency (eta) of spectral-conversion cells and compared with those of bare solar cells as a reference. Preliminary experimental results revealed that in an optimized PV cell, an enhancement of (0.64+0.01)% (from 16.03% to 16.67%) in Delta eta of a Si-based PV cell was achieved.
Improvement of conversion efficiency of silicon solar cells using up-conversion molybdate La2Mo2O9:Yb,R (R=Er, Ho) phosphors
(2011-08-01)
Chen, Yen-Chi
;
Chen, Teng-Ming
;
應用化學系
;
Department of Applied Chemistry
The goal of this work was aimed to improve the power conversion efficiency of single crystalline silicon-based photovoltaic cells by using the solar spectral conversion principle, which employs an up-conversion phosphor to convert a low energy infrared photon to the more energetic visible photons to improve the spectral response. In this study, the surface of multicrystalline silicon solar cells was coated with an up-conversion molybdate phosphor to improve the spectral response of the solar cell in the near-infrared spectral range. The short circuit current (I-sc), open circuit voltage (V-oc), and conversion efficiency (eta) of spectral conversion cells were measured. Preliminary experimental results revealed that the light conversion efficiency of a 1.5%-2.7% increase in Si-based cell was achieved.
Investigations into thermoluminescence and afterglow characterization of strontium aluminates with boron-modification and reductions via sol-gel route
(2012-10-01)
Chen, I-Cherng
;
Chen, Ker-Kong
;
Chen, Hong-Sen
;
Du, Je-kang
;
Lin, Tsao-Jen
The effects of strontium aluminates of SrAl2O4:Eu2+,Dy3+ (SAED) and boron-modified SAED (BSAED) phases synthesized from a sol-gel process on thermoluminescence (TL) along with their afterglow properties were systematically investigated with thermal activation in the different atmospheres. The result showed that the addition of boron and the reduction routes of Eu3+ to Eu2+ in SrAl2O4:Dy3+ were related to phosphorescent decay properties. The aid of Dy3+ to induce the hole-trapping effect required both SAED and BSAED to be heated at 1300 degrees C under the H-2/N-2 (5%: 95%) atmosphere. However, the trapping behavior of the reductions of SAED in nitrogen was similar to the compound without Dy3+ co-doping SrAl2O4:Eu2+ (SAE) in H-2/N-2 (5%: 95%). BSAED showed deeper traps in situ compared to SAED which contained no boron, and this led to the better afterglow properties of BSAED than those of SAED. The afterglow spectrum of BSAED showed two peaks at 400+/-1 nm and 485+/-1 nm, which were two individuals composed and contributed from different depths of traps at 0.57 and 0.76 eV, accordingly. The depth of the traps was calculated from the Hoogenstraaten's plot of glow curves. The calculations for SAED and SAE were at around 0.43 and 0.18 eV, respectively.
Synthesis, composition optimization, and VUV photoluminescence characterization of (Y,Gd) (V,P) O-4 : Eu3+ as a potential red-emitting plasma-display panel phosphor
(2007-12-01)
Wu, Chia-Chin
;
Cheng, Bing-Ming
;
Chen, Teng-Ming
;
應用化學系
;
Department of Applied Chemistry
The synthesis, composition optimization, VUV Photoluminescence (PL) spectra, and optical properties, of (Y, Gd) (V, P)O-4 : Eu3+ phosphors were investigated by synchrotron radiation. The VUV PLE spectra and the correlation among VUV PL intensity, lambda(em), and Eu3+, Gd3+, and P-content were established. The PLE spectral studies showed that (Y, Gd) (V, P)O-4: Eu3+ exhibited significant absorption in the VUV range. The VUV PL intensity was found to enhance with PO43- and Gd3+ -doping. Furthermore, the chromaticity characteristics of (Y, Gd) (V, P)O-4: Eu3+ were also found to be (0.6614, 0.3286) and compared against (Y, Gd)BO3:Eu3+ as a reference. Based on the characterization results, we are currently improving and evaluating the potential application of (Y, Gd) (V, P)O-4: Eu3+ as a new red-emitting PDP phosphor.

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