Browsing by Author "Lin, Sheng-Chia"

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Efficient multilayer red fluorescent polymer light-emitting diodes by host and guest blend system
(2010-05-01)
Syu, Wun-Shing
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Lin, Sheng-Chia
;
Tseng, Shin-Rong
;
Chen, Chun-Yu
;
Liu, Chang-Yao
Efficient red light polymer light-emitting diodes are obtained by energy transfer from host and guest blend system. Two kinds of blend systems, SPB02:(10-(2-benzothiazolyl)-1,1,7,7-tetramethyl-2,3,6,7-tetrahydro-1H,5H,11H-[1] benzopyrano [6,7,8-ij]quinolizin-11-one)(C545T):4-(dicyanomethylene)-2-t-butyl-6-(1,1,7,7-tetramethyljulolidyl-9-enyl)-4H-pyran (DCJTB) and SuperYellow (SY):poly(3,3'''-didodecylquaterthiophene) (PQT-12), are used as the active layers. C545T is a green emitter, acting as an assistant dopant to improve the energy transfer from blue SPB02 host to red DCJTB. The efficiency can achieve to 3.3 cd/A for DCJTB and 3.5 cd/A for PQT-12 system by multilayer device structure with 2,2,2 ''-(1,3,5-phenylene)-tris(1-phenyl-1H-benzimidazole) (TPBi) as electron transport layer. The SuperYellow:PQT-12 device shows great luminance of 16,930 cd/m(2). (C) 2010 Elsevier B.V. All rights reserved.
High-performance poly(2,3-diphenyl-1,4-phenylene vinylene)-based polymer light-emitting diodes by blade coating method
(2011-08-03)
Liao, Yung-Ming
;
Shih, Hung-Min
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Hsu, Kuang-Hui
;
Hsu, Chain-Shu
;
Chao, Yu-Chiang
A new series of super high brightness and luminance efficient poly(2,3-diphenyl-1,4-phenylene vinylene) (DP-PPV)-based electroluminescent (EL) polymers containing methoxy or long branched alkoxy chains were synthesized via Gilch polymerization. The branched alkoxy groups were introduced to enhance solubility for blade and spin-coating processes. Monomers of DMeO-PPV and m-Ph-PPV were used to increase steric hindrance and prevent close packing of the main chain. By controlling the feeding ratio of different monomers during polymerization, DP-PPV derivatives with high molecular weight were obtained. All synthesized polymers possess high glass transition temperatures and thermal stabilities. The maximum photoluminescent emissions of the thin films are located between 544 and 547 nm. Cyclic voltammetry analysis reveals that the band gaps of these light-emitting materials are in the range of 2.75 -2.84 eV. Blade coating was used to fabricate multilayer polymer light-emitting diodes. A multilayer electroluminescent device with the configuration of ITO/PEDOT:PSS/TFB/P1/TPBi/LiF/Al exhibited a very high luminescence efficiency (10.96 cd A(-1)). The maximum brightness of the multilayer EL device ITO/PEDOT:PSS/TFB/P3/CsF/Al reached up to 78,050 cd m(-2) with a low turn-on voltage (4.0 V). For further investigation, polymer P3 was blended with DPPFBNA to achieve white light-emitting device; the multilayer devices generated a maximum brightness of 1085 cd m(-2) and a luminance efficiency of 0.75 cd A(-1), with CIE coordinates (0.28, 0.33) at 11 V. (C) 2011 Elsevier Ltd. All rights reserved.
Using dual plasma treatment to improve electrical characteristics and reduce flicker noise of high-kappa HfO2 LTPS-TFTs
(2015-09-01)
Chang, Kow-Ming
;
Huang, Bo-Wen
;
Wu, Chien-Hung
;
Deng, I-Chung
;
Chang, Ting-Chia
This study demonstrated the application of a dual plasma treatment to low-temperature polycrystalline-silicon thin-film transistors (LTPS-TFTs) comprising a self-aligned phosphorus implantation source and drain, high-kappa HfO2 gate dielectric, and aluminum metal gate. The dual plasma treatment involves a pre-deposition CF4 plasma treatment at a high-kappa/poly-Si interface and post-deposition N-2 plasma treatment at a high-kappa HfO2 gate dielectric; this treatment enables reducing the interface-trap-state defects at the high-kappa/poly-Si interface, grain boundary traps in the poly-Si channel film, and oxygen vacancy V-o in the high-kappa HfO2 gate dielectric. Thus, LTPS-TFTs with dual plasma treatment demonstrate excellent electrical characteristics such as threshold voltage, subthreshold swing, transconductance, driving current, and on/off current ratio. Flicker noise, also referred to as 1/f noise, caused by fluctuations of carriers transported in the grain boundary and the trapped carriers per unit oxide volume (N-t) can be suppressed. Therefore, high performance LTPS-TFTs subjected to dual plasma treatment can be appropriately applied to active matrix liquid phase-crystal display on system-on-panel technology. (C) 2015 Elsevier Ltd. All rights reserved.