Browsing by Author "Li, Chia-Hung"

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A lighting mechanism for flat electron emission lamp
(2009-03-02)
Li, Jung-Yu
;
Chen, Shih-Pu
;
Li, Chia-Hung
;
Lin, Yi-Ping
;
Chou, Yen-I
We propose a lighting mechanism for generating uniform planar light. The device integrates electron beams induced by gas discharge with cathodoluminescence at the anode, where the spectra of the emitted light depend entirely on the phosphor materials coated on the anode. Consequently, ultraviolet is not required and the usage of mercury can be avoided. In addition, the features of double-side lighting, transparency, and gray-scale images indicate that the flat electron emission lamp might become potential candidate for the next generation green lighting source.
Discharge and photo-luminance properties of a parallel plates electron emission lighting device
(2011-01-03)
Li, Chia-Hung
;
Liu, Ming-Chung
;
Chiang, Chang-Lin
;
Li, Jung-Yu
;
Chen, Shih-Pu
The gas discharge and photo-luminance properties of a planar lighting source featuring highly uniform light emission and mercury-free design were studied. The current density-voltage characteristics and the associated gas discharge of the devices operating with the values of the ratio of electric field to gas pressure (E/p) between 4.3 kV/Torr-cm and 35.7 kV/Torr-cm indicate that the width of the cathode fall extends over the entire gap between the two electrodes and the device is mostly in the obstructed discharge regime. The optical emission analysis confirmed the electron collision-induced gas emissions and strong effect of gas pressure on the phosphor emission when operated at constant current density, both are indicative of the primary roles played by the electron energy. (C)2011 Optical Society of America
Enhancement of the field emission properties of low-temperature-growth multi-wall carbon nanotubes by KrF excimer laser irradiation post-treatment
(2006-11-01)
Li, Chia-Hung
;
Liu, Han-Chi
;
Tseng, Shih-Chun
;
Lin, Yi-Ping
;
Chen, Shih-Pu
Multi-wall carbon nanotube (CNT) films were fabricated by microwave plasma chemical vapor deposition at low temperatures (similar to 500 degrees C). The films when properly post-treated by laser irradiation exhibited a factor of 2-3 enhancement in the emission cur-rent, while the turn-on field (E-on) was reduced from 4.89-5.22 to 2.88-3.15 V/mu m. The introduction of excessive oxygen during laser irradiation, however, degrades the performance of field emission properties drastically. Raman spectroscopy measurements revealed the intimate correlation between the parameter I-D/I-G (intensity ratio between the two representative Raman peaks seen in carbon nanotubes) and the field emission performance. The scanning electron microscopy (SEM) and transmission electron microscopy (TEM) analyses showed that the irradiation-induced modification of the tube morphology and crystallinity might be responsible for the observations. (c) 2006 Elsevier B.V. All rights reserved.
Physical properties of amorphous InGaZnO(4) films doped with Mn
(2009-03-02)
Liu, Shiu-Jen
;
Fang, Hau-Wei
;
Su, Shih-Hao
;
Li, Chia-Hung
;
Cherng, Jyh-Shiarn
Amorphous InGaZnO(4) (a-IGZO) films doped with various concentrations of Mn have been fabricated by using pulsed-laser deposition technique. Optical, electrical, and magnetic properties of the prepared Mn-doped a-IGZO films were investigated. The resistivity, carrier concentration, and carrier mobility of the a-IGZO films were found to be, respectively, increased, decreased, and enhanced by Mn doping. Moreover, the optical transmission is slightly increased in the visible range and the optical band gaps are not affected in the Mn-doped films. Room-temperature ferromagnetism has been observed in the field-dependent magnetization measurements.
Physical properties of amorphous InGaZnO4 films doped with Mn
(2009-03-02)
Liu, Shiu-Jen
;
Fang, Hau-Wei
;
Su, Shih-Hao
;
Li, Chia-Hung
;
Cherng, Jyh-Shiarn
Amorphous InGaZnO4 (a-IGZO) films doped with various concentrations of Mn have been fabricated by using pulsed-laser deposition technique. Optical, electrical, and magnetic properties of the prepared Mn-doped a-IGZO films were investigated. The resistivity, carrier concentration, and carrier mobility of the a-IGZO films were found to be, respectively, increased, decreased, and enhanced by Mn doping. Moreover, the optical transmission is slightly increased in the visible range and the optical band gaps are not affected in the Mn-doped films. Room-temperature ferromagnetism has been observed in the field-dependent magnetization measurements.
Properties of gated single free-standing carbon nanotube with multiple growth sequence
(2007-10-01)
Tseng, Shih Chun
;
Tsai, Ching Hsiang
;
Li, Chia-Hung
;
Peng, Wen Yang
;
Chen, Shih-Pu
In this paper, we discuss an approach to fabricating a carbon nanotubes (CNTs) gate electrode structure for cold cathode emitter applications. The field emission behavior of the structure was studied by using single vertically aligned free-standing CNTs of various lengths and gate electrodes of various sizes to determine the optimal emission structure. A single CNT electrode source with a gate electrode was fabricated by combining optical lithography, electron-beam lithography (EBL), and inductively coupled plasma chemical vapor deposition (ICP-CVD). A single mask was adopted to define the gated structure and nano sized catalyst for CNT growth. A vertically aligned CNT was then grown within the gate hole by ICP-CVD. The CNT height inside the gate could be lengthened by multiple growth processes without affecting the field emission capability. The best turn-on fields, defined as the field required to generate an emission current of 1 nA, were approximately 1.66 and 1.38 V/mu m, respectively. The turn-on field emission current saturated when the CNT length was about the same as the gate height.
Secondary electron emission characteristics of oxide electrodes in flat electron emission lamp
(2016-01-01)
Chiang, Chang-Lin
;
Zeng, Hui-Kai
;
Li, Chia-Hung
;
Li, Jung-Yu
;
Chen, Shih-Pu
The present study concerns with the secondary electron emission coefficient,., of the cathode materials used in the newly developed flat electron emission lamp (FEEL) devices, which essentially integrates the concept of using cathode for fluorescent lamp and anode for cathode ray tube (CRT) to obtain uniform planar lighting. Three different cathode materials, namely fluorine-doped tin oxide (FTO), aluminum oxide coated FTO (Al2O3/FTO) and magnesium oxide coated FTO (MgO/FTO) were prepared to investigate how the variations of. and working gases influence the performance of FEEL devices, especially in lowering the breakdown voltage and pressure of the working gases. The results indicate that the MgO/FTO bilayer cathode exhibited a relatively larger effective secondary electron emission coefficient, resulting in significant reduction of breakdown voltage to about 3kV and allowing the device to be operated at the lower pressure to generate the higher lighting efficiency. (C) 2016 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).