Browsing by Author "Hsu, Chian-Shu"

Now showing 1 - 4 of 4

Deep blue light-emitting diode based on high molecular weight poly(9,9-dioctylfluorene) with high efficiency and color stability
(2008-06-01)
Tseng, Shin-Rong
;
Li, Shiuan-Yi
;
Meng, Hsin-Fei
;
Yu, Yi-Hsiang
;
Yang, Chia-Ming
A highly efficient deep blue polymer light-emitting diode based on poly(9,9-dioctylfluorene) is demonstrated. The performance is found to increase significantly with the molecular weight. Two different molecular weights are compared, one is 71,000 and the other is 365,000. The electroluminescent efficiency and color stability are improved by slightly doping hole traps into the emission layer and bilayer structure. The maximum efficiency is 3.8 cd/A with the corresponding external quantum efficiency of 3.7% at deep blue with Commission Internationale de L'Eclairage (CIE) coordinate at (0.15, 0.09). Stable blue emission is maintained up to 6600 cd/m(2) without growth of green shoulder in emission spectrum. (C) 2007 Elsevier B.V. All rights reserved.
High-efficiency blue multilayer polymer light-emitting diode based on poly(9,9-dioctylfluorene)
(2007-04-15)
Tseng, Shin-Rong
;
Li, Shiuan-Yi
;
Meng, Hsin-Fei
;
Yu, Yi-Hsiang
;
Yang, Chia-Ming
A highly efficient blue polymer light-emitting diode based exclusively on commercial poly(9,9-dioctylfluorene) and poly[(9,9-dioctylfluorenyl-2,7-diyl)-co-(4,4(')-(N-(4-s-butylphenyl)) diphenylamine)] is demonstrated. High electroluminescent efficiency is achieved by enhancing electron currents and making devices in multilayered structures. CsF/Al is used as the efficient electron injection cathode, and the fabrication process is in the glove box to enhance electron mobility by reducing oxygen adsorption. The multilayer structure is prepared by the liquid buffer layer technique. The maximum efficiency is 2.5 cd/A at deep blue with the corresponding external quantum efficiency of 2%.
Polymer infrared photo-detector with high sensitivity up to 1100 nm
(2011-08-01)
Chen, En-Chen
;
Tseng, Shin-Rong
;
Chao, Yu-Chiang
;
Meng, Hsin-Fei
;
Wang, Chih-Feng
We reported a low band-gap conjugated polymer, poly[2,3-bis(4-(2-ethylhexyloxy)phenyl)-5,7-di(thiophen-2-yl)thienol[3,4-b]pyrazine] (PDTTP), was studied for the near infrared (NIR) photo-detector application. PDTTP shows intense absorption in NIR wavelength (to 1000 nm) and the estimated optical and electrochemical band-gaps of PDTTP are quite small around 1.15 eV and 1.08 eV, respectively. The low band-gap and the extended long wavelength absorption originates from the introduction of alternating TP units when its parent polythieno[3,4-b]pyrazine shows excellent narrow band-gap properties. Therefore, the relatively low band-gap and intense absorption in long wavelength of PDTTP make itself a promising candidate for near-infrared photo-detector. The hole mobility of the PDTTP measured from the bottom contact field effect transistor is around 1.40 x 10(-3) cm(2)/V s with a on/off ratio of 2100. The photo-detector based on bulk hetero-junction PDTTP and (6,6)-phenyl-C61-butyric acid methyl ester blend (PCBM) has the incident photon-to-electron conversion efficiency 28.9% at 1000 nm (-5 V) and 6.2% at 1100 nm (-5 V). This photo-detector can be operated at a high-speed of 1 MHz. The experimental result suggests the potential applications of low band-gap conjugated polymers on near-infrared photo-detectors. (C) 2011 Elsevier B.V. All rights reserved.
Polymer solar cell by blade coating
(2009-08-01)
Chang, Yu-Han
;
Tseng, Shin-Rong
;
Chen, Chun-Yu
;
Meng, Hsin-Fei
;
Chen, En-Chen
Polymer bulk hetero-junction solar cells of poly(3-hexylthiophene) (P3HT) donor and (6,6)-phenyl-C61-butyric acid methyl ester (PCBM) acceptor are fabricated by blade coating in toluene solution. Desired donor-acceptor self-organization is achieved without the slow drying process and high boiling point solvent. Power conversion efficiency is 3.8%. much higher than the 2.6% obtained by spin coating in toluene solution. The blade coating method has nearly 100% material usage and can be integrated in the roll-to-roll process with high throughput production. (C) 2009 Elsevier B.V. All rights reserved.