Browsing by Author "Shieh, Han-Ping"

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Design and Evaluation of Light Spread Function for Area-Adaptive LCD System
(2009-01-01)
Cheng, Yu-Kuo
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Lu, Yen-Hsing
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Tien, Chung-Hao
;
Shieh, Han-Ping
;
光電工程學系
A methodology, based on two-dimensional super-Gaussian light spread functions (LSFs), was studied for the light-emitting-diode (LED) backlighting system in the high dynamic range (HDR) liquid crystal displays (LCDs). We proposed a novel LED-based optomechanical configuration to implement the desirable luminous pattern. A dual-liquid-crystal-panel system was constructed as a pseudo-HIE)R LCD to evaluate the super-Gaussian illumination. The proposed HDR scheme was verified via the current platform: overall luminance uniformity, contrast ratio and processing speed could be improved by factors of 1.55, 1.95-4.15, and 4.82, respectively. The design flexibility made the methodology applicable to any panel dimension and backlight division of the HDR LCDs, and to the conventional full-on backlighting LCDs as well.
Enhanced stability of thin film transistors with double-stacked amorphous IWO/IWO:N channel layer
(2018-06-01)
Lin, Dong
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Pi, Shubin
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Yang, Jianwen
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Tiwari, Nidhi
;
Ren, Jinhua
In this work, bottom-gate top-contact thin film transistors with double stacked amorphous IWO/ IWO:N channel layer were fabricated. Herein, amorphous IWO and N-doped IWO were deposited as front and back channel layers, respectively, by radio-frequency magnetron sputtering. The electrical characteristics of the bi-layer-channel thin film transistors (TFTs) were examined and compared with those of single-layer-channel (i.e., amorphous IWO or IWO:N) TFTs. It was demonstrated to exhibit a high mobility of 27.2 cm(2)V(-1 )s(-1) and an on/off current ratio of 10(7).Compared to the single peers, bi-layer a-IWO/IWO:N TFTs showed smaller hysteresis and higher stability under negative bias stress and negative bias temperature stress. The enhanced performance could be attributed to its unique double-stacked channel configuration, which successfully combined the merits of the TFTs with IWO and IWO:N channels. The underlying IWO thin film provided percolation paths for electron transport, meanwhile, the top IWO:N layer reduced the bulk trap densities. In addition, the IWO channel/gate insulator interface had reduced defects, and IWO:N back channel surface was insensitive to the ambient atmosphere. Overall, the proposed bi-layer a-IWO/IWO:N TFTs show potential for practical applications due to its possibly long-term serviceability.
Microelectro mechanical system for magneto-optic data storage apparatus
(2005-09-08)
Hsu, Wensyang
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Shieh, Han-Ping
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Sun, Yi Ting
The present invention relates to a Microelectro mechanical system structure. More specifically the invention relates to utilize a sacrificial layer to fabricate an air bearing structure, followed by forming an aperture, and reducing the aperture to nano-scale by electroplating. And then, by using of two thick film photoresist films for twice electroplating fabrication, for fabricate metal microcoils having high aspect ratio structure and interconnection metal line, to achieve efficiencies of utilizing area and reducing resistance. Moreover, proceed lithography depends on different portions and exposure dose. Then form a single photoresist film to have a specific dimension and thickness structure, finally, by using reflow process, forming a magneto-optic (MO) pickup head comprises of Supersphere Solid Immersion Lens (SSIL), nano-aperture, microcoils and air bearing by using an integrated fabrication, with advantages such as no high cost device and precise apparatus are required in the process of fabrication, mass production in batch fabrication, without step of assembly, for high-density data storage and rewritable record.
Nitrogenated amorphous InGaZnO thin film transistor
(2011-01-31)
Liu, Po-Tsun
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Chou, Yi-Teh
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Teng, Li-Feng
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Li, Fu-Hai
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Shieh, Han-Ping
This work presents the electrical characteristics of the nitrogenated amorphous InGaZnO thin film transistor (a-IGZO:N TFT). The a-IGZO: N film acting as a channel layer of a thin film transistor (TFT) device was prepared by dc reactive sputter with a nitrogen and argon gas mixture at room temperature. Experimental results show that the in situ nitrogen incorporation to IGZO film can properly adjust the threshold voltage and enhance the ambient stability of a TFT device. Furthermore, the a-IGZO: N TFT has a 44% increase in the carrier mobility and electrical reliability and uniformity also progress obviously while comparing with those not implementing a nitrogen doping process. (C) 2011 American Institute of Physics. [doi:10.1063/1.3551537]
Performance improvement of white phosphorescent organic light-emitting diodes by using composite host structure to enhance the carrier injection
(2010)
Juang, Fuh-Shyang
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Hong, Lin-Ann
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Chen, Cheng-Yin
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Wang, Shun-Hsi
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Tsai, Yu-Sheng
Device characteristics of phosphorescent OLEDs with composite host structure were investigated by co-doping hole and electron transport-type hosts in emitting layer. The improved of charge injection and the confined of triplet excitons within recombination zone were achieved. White-OLED shows the efficiencies of 34.5 cd/A and 24 lm/W at 1000 cd/m(2).
Power Efficiency Improvement of White Phosphorescent Organic Light-Emitting Diode with Thin Double-Emitting Layers and Hole-Trapping Mechanism
(2011-04-01)
Juang, Fuh-Shyang
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Hong, Lin-Ann
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Wang, Shun-Hsi
;
Tsai, Yu-Sheng
;
Gao, Ming-Hong
This study is carried out to discuss how to reduce the driving voltage of blue phosphorescent organic light-emitting diodes (PHOLEDs) by using a thin double-emission layer. A hole transport-type host (TCTA) is inserted between the hole transport layer (TAPC) and the emitting layer (EML), constituting a buffer layer between them with the aim of improving charge carrier balance. Furthermore, in this study, we also utilize the interface between double light-emitting layers of devices by codoping them with a red phosphorescent dopant [Os(bpftz)(2)(PPh(2)Me)(2)]. An Os complex with a high-lying highest occupied molecular orbital (HOMO) energy level (trapping holes) is codoped at the interface between emitting layers and an exciton-formation zone is expanded to obtain a white PHOLED with high efficiency. From the results, the optimal structure of the white device exhibits a yield of 35 cd A(-1), a power efficiency of 22 lm W(-1), and CIE coordinates of (0.33; 0.38) at a luminance of 1000 cdm(-2). Furthermore, the power efficiency can be improved to 30 lm W(-1) by attaching the outcoupling enhancement film. (C) 2011 The Japan Society of Applied Physics
Spatial-temporal division in field sequential color technique for color filterless LCD
(2007)
Chen, Che-Chin
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Chen, Yi-Fu
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Liu, Ti-Ti
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Chen, Chun-Ho
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Ho, Ming-Tsung
For color filterless display, a novel spatial and temporal division (STD) field sequence color (FSC) display technique divides each frame into many temporary sub-frames for improving color breakup (CBU) and motion blur effects. Fast refresh frequencies enhance the image quality. Spatial and temporal division achieves low cost and power consumption.
TiO2 nanowire-templated hierarchical nanowire network as water-repelling coating
(2017-11-01)
Hang, Tian
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Chen, Hui-Jiuan
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Xiao, Shuai
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Yang, Chengduan
;
Chen, Meiwan
Extraordinary water-repelling properties of superhydrophobic surfaces make them novel candidates for a great variety of potential applications. A general approach to achieve superhydrophobicity requires low-energy coating on the surface and roughness on nano-and micrometre scale. However, typical construction of superhydrophobic surfaces with micro-nano structure through top-down fabrication is restricted by sophisticated fabrication techniques and limited choices of substrate materials. Micro-nanoscale topographies templated by conventional microparticles through surface coating may produce large variations in roughness and uncontrollable defects, resulting in poorly controlled surface morphology and wettability. In this work, micro-nanoscale hierarchical nanowire network was fabricated to construct self-cleaning coating using one-dimensional TiO2 nanowires as microscale templates. Hierarchical structure with homogeneous morphology was achieved by branching ZnO nanowires on the TiO2 nanowire backbones through hydrothermal reaction. The hierarchical nanowire network displayed homogeneous micro/nano-topography, in contrast to hierarchical structure templated by traditional microparticles. This hierarchical nanowire network film exhibited high repellency to both water and cell culture medium after functionalization with fluorinated organic molecules. The hierarchical structure templated by TiO2 nanowire coating significantly increased the surface superhydrophobicity compared to vertical ZnO nanowires with nanotopography alone. Our results demonstrated a promising strategy of using nanowires as microscale templates for the rational design of hierarchical coatings with desired superhydrophobicity that can also be applied to various substrate materials.