Browsing by Author "Hwang, Chuan-Chou"

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Effects of accumulated laser pulses on (Pb,Sr)TiO(3) films post-excimer laser annealed at low temperatures
(2007-08-01)
Wang, Jyh-Liang
;
Lai, Yi-Sheng
;
Chiou, Bi-Shiou
;
Shye, Der-Chi
;
Hwang, Chuan-Chou
In this article, we report the effect of excimer laser annealing (ELA) on the characteristics of (Pb,Sr)TiO(3) (PSrT) films. The unirradiated and irradiated films are characterized by atomic force microscope (AFM), X-ray photoelectron spectroscopy, X-ray diffractometer (XRD), transmission electron microscopy (TEM), and electron energy loss spectroscopy (EELS). It is found that the crystallinity is improved and the oxygen content is increased by ELA. Besides, the surface morphology becomes rough after ELA. Moreover, PSrT films irradiated by ELA are found to increase the grain size near the surface. The material properties of unirradiated and irradiated films, as well as the characteristics of PSrT films irradiated with various laser pulses, will be explored in this study. (c) 2007 Elsevier B.V. All rights reserved.
Effects of accumulated laser pulses on (Pb,Sr)TiO3 films post-excimer laser annealed at low temperatures
(2007-08-01)
Wang, Jyh-Liang
;
Lai, Yi-Sheng
;
Chiou, Bi-Shiou
;
Shye, Der-Chi
;
Hwang, Chuan-Chou
In this article, we report the effect of excimer laser annealing (ELA) on the characteristics of (Pb,Sr)TiO3 (PSrT) films. The unirradiated and irradiated films are characterized by atomic force microscope (AFM), X-ray photoelectron spectroscopy, X-ray diffractometer (XRD), transmission electron microscopy (TEM), and electron energy loss spectroscopy (EELS). It is found that the crystallinity is improved and the oxygen content is increased by ELA. Besides, the surface morphology becomes rough after ELA. Moreover, PSrT films irradiated by ELA are found to increase the grain size near the surface. The material properties of unirradiated and irradiated films, as well as the characteristics of PSrT films irradiated with various laser pulses, will be explored in this study. (c) 2007 Elsevier B.V. All rights reserved.
Field-Emission Stability of Hydrothermally Synthesized Aluminum-Doped Zinc Oxide Nanostructures
(2012-07-01)
Hsieh, Tsang-Yen
;
Wang, Jyh-Liang
;
Yang, Po-Yu
;
Hwang, Chuan-Chou
;
Shye, Der-Chi
The Al-doped ZnO (AZO) nanostructures field-emission arrays (FEAs) were hydrothermally synthesized on AZO/glass substrate. The samples with Al-dosage of 3 at.% show the morphology as nanowires vertically grown on the substrates and a structure of c-axis elongated single-crystalline wurtzite. The good field-emission (i.e., the large anode current and low fluctuation of 15.9%) can be found by AZO nanostructure FEAs with well-designed Al-dosage (i.e., 3 at.%) because of the vertical nanowires with the less structural defects and superior crystallinity. Moreover, the Full width at half maximum (FWHM) of near band-edge emission (NBE) decreased as the increase of annealing temperature, representing the compensated structural defects during oxygen ambient annealing. After the oxygen annealing at 500 degrees C, the hydrothermal AZO nanostructure FEAs revealed the excellent electrical characteristics (i.e., the larger anode current and uniform distribution of induced fluorescence) and enhanced field-emission stability (i.e., the lowest current fluctuation of 5.97%).
Oxygen annealing effect on field-emission characteristics of hydrothermally synthesized Al-doped ZnO nanowires
(2013-09-01)
Wang, Jyh-Liang
;
Hsieh, Tsang-Yen
;
Yang, Po-Yu
;
Hwang, Chuan-Chou
;
Shye, Der-Chi
Al-doped ZnO (AZO) nanowires (NWs) were synthesized using low-temperature hydrothermal growth to investigate field emission (FE) characteristics. The intensity ratio of NBE peak to DLE peak (R = I-NBE/I-DLE) increases and the half-maximum of NBE peaks (FWHMNBE) decreases with the Al contents. Experimental results reveal the FE characteristics of AZO NWs are functions of Al content. Moreover, the larger R value and the smaller FWHMNBE are found as the oxygen annealing temperature increases. The hydrothermal AZO NWs annealed in oxygen ambience with an appropriate temperature (i.e. 300-500 degrees C) can demonstrate the further improved FE properties (i.e. the turn-on field of 1.70 V/mu m (at 1 mu A/cm(2)), threshold field of 2.92 V/mu m (at 1 mA/cm(2)), and beta of 4547). (C) 2012 Elsevier B.V. All rights reserved.
pH-Sensing Characteristics of Hydrothermal Al-Doped ZnO Nanostructures
(2013)
Wang, Jyh-Liang
;
Yang, Po-Yu
;
Hsieh, Tsang-Yen
;
Hwang, Chuan-Chou
;
Juang, Miin-Horng
Highly sensitive and stable pH-sensing properties of an extended-gate field-effect transistor (EGFET) based on the aluminumdoped ZnO (AZO) nanostructures have been demonstrated. The AZO nanostructures with different Al concentrations were synthesized on AZO/glass substrate via a simple hydrothermal growth method at 85 degrees C. The AZO sensing nanostructures were connected with the metal-oxide-semiconductor field-effect transistor (MOSFET). Afterwards, the current-voltage (I-V) characteristics and the sensing properties of the pH-EGFET sensors were obtained in different buffer solutions, respectively. As a result, the pH-sensing characteristics of AZO nanostructured pH-EGFET sensors with Al dosage of 3 at.% can exhibit the higher sensitivity of 57.95mV/pH, the larger linearity of 0.9998, the smaller deviation of 0.023 in linearity, the lower drift rate of 1.27mV/hour, and the lower threshold voltage of 1.32V with a wider sensing range (pH 1 similar to pH 13). Hence, the outstanding stability and durability of AZO nanostructured ionic EGFET sensors are attractive for the electrochemical application of flexible and disposable biosensor.
The effects of oxygen annealing on the electrical characteristics of hydrothermally grown zinc oxide thin-film transistors
(2012-11-01)
Wang, Jyh-Liang
;
Yang, Po-Yu
;
Hsieh, Tsang-Yen
;
Hwang, Chuan-Chou
;
Shye, Der-Chi
High-performance transparent zinc oxide (ZnO) thin-film transistors (TFTs) with location-controlled lateral-grain growth were fabricated by hydrothermal method. The ZnO active channel was laterally grown with aluminum-doped ZnO (AZO) seed layer underneath the Ti/Pt film. Compare to the unannealed ZnO TFTs, the annealed devices reveal the high-quality ZnO layer with the compensated structural defects in the channel region after oxygen ambient annealing at 400 degrees C. Therefore, the superior device performances (i.e. the excellent filed-effect mobility of 9.07 cm(2)/V s, positive threshold voltage of 2.25 V. high on/off current ratio of similar to 10(6), and low gate leakage current of <1 nA) of hydrothermally grown ZnO TFTs can be achieved with oxygen ambient annealing. (c) 2012 Elsevier Ltd. All rights reserved.
Zinc oxide thin-film transistors fabricated via low-temperature hydrothermal method
(2013-09-01)
Wang, Jyh-Liang
;
Yang, Po-Yu
;
Juang, Miin-Horng
;
Hsieh, Tsang-Yen
;
Hwang, Chuan-Chou
Transparent high-performance ZnO TFTs have been fabricated via low-temperature hydrothermal method. The dip of H3PO4 solution prior to the hydrothermal process can form the under-cut AZO seed layer and benefit for the control of ZnO growth. While the use of under-cut AZO seed layer with proper design of channel length, the lateral ZnO growth can be artificially controlled in the desired location to make a continuous active-layer and nearly single one vertical grain boundary cross to the current flow in the channel region. ZnO TFTs indicate the behavior of n-channel enhancement-mode devices. The optimum design of channel length (i.e. L=10 mu m) can provide enough space for the lateral growth of large ZnO grains with less channel defects and bring about the advanced device characteristics (i.e. the positive threshold voltage of 3.0 V, mobility of 9.03 cm(2)/V.s, on/off current ratio >10(6), gate leakage of <1 nA with less fluctuation, and extremely high drain current >500 mu A). (C) 2012 Elsevier B.V. All rights reserved.