Browsing by Author "Lin, Y. C."

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A side-by-side comparison of Daya Bay antineutrino detectors
(1970-01-01)
An, F. P.
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An, Q.
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Bai, J. Z.
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Balantekin, A. B.
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Band, H. R.
"The Daya Bay Reactor Neutrino Experiment is designed to determine precisely the neutrino mixing angle theta(13) with a sensitivity better than 0.01 in the parameter sin(2) 2 theta(13) at the 90% confidence level. To achieve this goal, the collaboration will build eight functionally identical antineutrino detectors. The first two detectors have been constructed, installed and commissioned in Experimental Hall 1, with steady data-taking beginning September 23, 2011. A comparison of the data collected over the subsequent three months indicates that the detectors are functionally identical, and that detector-related systematic uncertainties are smaller than requirements. (C) 2012 Elsevier B.V. All rights reserved."
An apparatus for studying spallation neutrons in the Aberdeen Tunnel laboratory
(2013-09-21)
Blyth, S. C.
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Chan, Y. L.
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Chen, X. C.
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Ch, M. C.
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Hahn, R. L.
In this paper, we describe the design, construction and performance of an apparatus installed in the Aberdeen Tunnel laboratory in Hong Kong for studying spallation neutrons induced by cosmic-ray muons under a vertical rock overburden of 611 m water equivalent (m.w.e.). The apparatus comprises six horizontal layers of plastic-scintillator hodoscopes for determining the direction and position of the incident cosmic-ray muons. Sandwiched between the hodoscope planes is a neutron detector filled with 650 kg of liquid scintillator doped with about 0.06% of Gadolinium by weight for improving the efficiency of detecting the spallation neutrons. Performance of the apparatus is also presented. (C) 2013 Elsevier B.V. All rights reserved.
Biexciton emission from sol-gel ZnMgO nanopowders
(2010-05-10)
Chia, C. H.
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Lai, Y. J.
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Hsu, W. L.
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Han, T. C.
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Chiou, J. W.
We studied the power-dependent photoluminescence of Zn(1-x)Mg(x)O nanopowders grown by sol-gel method, at temperature T = 100 K. At moderate optical pumping intensity, a nonlinear emission band due to the radiative recombination of free biexcitons was detected. We found that the free biexciton binding energies of Zn(1-x)Mg(x)O nanopowder (0.01 <= x <= 0.05) are nearly constant (13.5 +/- 1.5 meV). (C) 2010 American Institute of Physics. [doi:10.1063/1.3428780]
Carrier dynamics in isoelectronic ZnSe(1-x)O(x) semiconductors
(2010-07-26)
Lin, Y. C.
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Chung, H. L.
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Chou, W. C.
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Chen, W. K.
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Chang, W. H.
This study explores the effects of both Oxygen and temperature on the carrier dynamics of isoelectronic ZnSe(1-x)O(x) (x=0.027 and 0.053) semiconductors using photoluminescence (PL) and time-resolved PL spectroscopy. We find that the Kohlrausch law is highly consistent with the complex decay traces induced by isoelectronic O traps, and the mechanism of carrier recombination undergoes a complicated change from trapped to free excitons with the increase in temperature. Complex recombination processes are clarified using the relaxation model based on various decay channels. These findings are consistent with the initial fall in the stretching exponent beta followed by its monotonic increase with increasing temperature. (C) 2010 American Institute of Physics. [doi:10.1063/1.3473776]
Carrier dynamics in isoelectronic ZnSe1-xOx semiconductors
(2010-07-26)
Lin, Y. C.
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Chung, H. L.
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Chou, W. C.
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Chen, W. K.
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Chang, W. H.
This study explores the effects of both Oxygen and temperature on the carrier dynamics of isoelectronic ZnSe1-xOx (x=0.027 and 0.053) semiconductors using photoluminescence (PL) and time-resolved PL spectroscopy. We find that the Kohlrausch law is highly consistent with the complex decay traces induced by isoelectronic O traps, and the mechanism of carrier recombination undergoes a complicated change from trapped to free excitons with the increase in temperature. Complex recombination processes are clarified using the relaxation model based on various decay channels. These findings are consistent with the initial fall in the stretching exponent beta followed by its monotonic increase with increasing temperature. (C) 2010 American Institute of Physics. [doi:10.1063/1.3473776]
Carrier dynamics in ZnxCd1-xO films grown by molecular beam epitaxy
(2016-01-01)
Cheng, F. J.
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Lee, Y. C.
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Hu, S. Y.
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Lin, Y. C.
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Tiong, K. K.
In this work, the carrier dynamics in Zn1-xCdxO thin films with different Cd contents grown by molecular beam epitaxy system have been investigated using photoluminescence and time-resolved photoluminescence measurements. The carrier lifetime can be estimated from the PL decay curve fitted by triple exponential function. The emission energy dependence and temperature dependence of the PL decay time indicate that carrier localization dominate the luminescence mechanism of the ZnCdO alloy semiconductor.
center dot-ray induced effects in Sm-doped strontium borate glasses
(2013)
Marinova, V.
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Tomov, V.
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Chuang, C. I.
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Lin, Y. C.
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Lin, S. H.
Strontium borate glasses SrB4O7 doped with Sm ions are prepared by conventional melting-quenching method. The effect of center dot-ray irradiation on the glass samples is studied by measuring the absorption spectra and the photoluminescence. It is found that the center dot -ray irradiation caused partial reduction of Sm3+ to Sm2+ at room temperature. Borate framework is supposed to be responsible for the Sm3+ to Sm2+ transition.
Controlled large strain of Ni silicide/Si/Ni silicide nanowire heterostructures and their electron transport properties
(2010-11-15)
Wu, W. W.
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Lu, K. C.
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Chen, K. N.
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Yeh, P. H.
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Wang, C. W.
Unusually large and compressively strained Si in nanoheterostructures of Ni silicide/Si/Ni silicide, in which the strain of the Si region can be achieved up to 10%, has been produced with point contact reactions between Si and Ni nanowires in an ultrahigh vacuum transmission electron microscope. The growth rate and relationships between the strain and the spacing of the Si region have been measured. Based on the rate and relationships, we can control the Si dimension and, in turn, the strain of remaining Si can be tuned with appropriate spacing. Since one-dimensional nanoheterostructures may have potential applications in nanoelectronic devices, the existent strain will further affect carrier mobility and piezoresistance coefficients in the Si region. Electrical measurements on the nanodevices from such nanoheterostructures show that the current output closely correlates with the Si channel length and compressive strain. (C) 2010 American Institute of Physics. [doi: 10.1063/1.3515421]
Controlling number of lasing modes for designing short-cavity self-mode-locked Nd-doped vanadate lasers
(2011-06-01)
Chen, Y. F.
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Huang, Y. J.
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Chiang, P. Y.
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Lin, Y. C.
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Liang, H. C.
A short-cavity Nd:YVO(4) laser is employed to confirm that a spontaneous mode locking (SML) typically occurs without employing an extra nonlinearity. We further experimentally demonstrate that reducing the number of longitudinal lasing modes can diminish the phase fluctuation and effectively improve the SML pulse stability. Considering the spatial hole-burning (SHB) effect, an analytical expression is derived to accurately estimate the number of longitudinal lasing modes for a practical design guideline.
Device linearity comparison of uniformly doped and delta-doped In0.52Al0.48As/In0.6Ga0.4As metamorphic HEMTs (vol 27, pg 535, 2006)
(2006-10-01)
Lin, Y. C.
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Chang, Edward Yi
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Yamaguchi, H.
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Hirayama, Y.
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Chang, X. Y.
Effect of donor-acceptor concentration ratios on nonradiative energy transfer in closely packed CdTe quantum dots
(2009-09-28)
Lin, Y. C.
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Wang, W. J.
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Chung, H. L.
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Chou, W. C.
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Chen, W. K.
This study investigates the dependence of Forster resonance energy transfer (FRET) on donor-acceptor (D/A) concentration ratios in mixed-size CdTe quantum dots (QDs) films by using photoluminescence (PL) and time-resolved PL spectroscopy. Experimental results indicate that an increasing donor concentration significantly quenches the emission intensity and lifetime in donor QDs and enhances that in acceptor QDs, providing clear evidence of increased FRET efficiency. When D/A ratio exceeds 6, however, the emission intensity and the lifetime of acceptors start to decline, reflecting a decreasing FRET efficiency because of a markedly declining availability of acceptor QDs. (C) 2009 American Institute of Physics. [doi:10.1063/1.3242371]
Effect of Fe2O3 coating on ZnO nanowires in photoelectrochemical water splitting: A synchrotron x-ray spectroscopic and spectromicroscopic investigation
(2020-06-01)
Lu, Y. R.
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Wang, Y. F.
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Chang, H. W.
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Huang, Y. C.
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Chen, J. L.
An array of ZnO/Fe2O3 core-shell nanowires (NW) for the highly efficient absorption of light and carrier collection is developed for use in photoelectrochemical (PEC) water-splitting. The oriented NW architecture favors physical matching, providing a direct electron conduction pathway and reducing the diffusion length of photogenerated holes. This work involves a combination of spectral imaging, spectromicroscopy and in situ x-ray absorption spectroscopy; spectra are obtained under operando conditions. Direct investigation of oriented nanowires using polarization-dependent x-ray spectromicroscopy enables the determination of the relationship between anisotropic electronic orbitals and charge carrier water-splitting efficiency. The results of O K-edge STXM demonstrated that the ZnO/Fe2O3 core-shell NW exhibits strong anisotropy and thus provides higher electron-hole transport efficiency than bare ZnO. In situ XAS revealed that interfacial charge transfer between Fe 3d and Zn 4p states enhances the photoelectrochemical reaction in the ZnO/Fe2O3 core-shell NW. The photogenerated electrons of Fe2O3 are transferred from Fe 3d states to the Zn 4p state under photoelectrochemical conditions.
Electrical Characteristics of HfO2 and La2O3 Gate Dielectrics for In0.53Ga0.47As MOS Structure
(2009)
Funamiz, K.
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Lin, Y. C.
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Kakushima, K.
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Ahmet, P.
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Tsutsui, K.
InGaAs MOS capacitors with HfO2 and La2O3 gate dielectrics have been investigated. La2O3 capacitor was found to result in large leakage current. This can be attributed to the annealing-induced As diffusion into La2O3 layer from InGaAs substrate. This leakage current was found to be suppressed by inserting HfO2 layer between La2O3 layer and InGaAs.
Electrical Characterization of Al(2)O(3)/n-InAs Metal-Oxide-Semiconductor Capacitors With Various Surface Treatments
(2011-06-01)
Trinh, H. D.
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Brammertz, G.
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Chang, E. Y.
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Kuo, C. I.
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Lu, C. Y.
Ex situ sulfide and HCl wet chemical treatments in conjunction with in situ trimethyl aluminum (TMA) pretreatment were performed before the deposition of Al(2)O(3) on n-InAs surfaces. X-ray photoelectron spectroscopy analyses show a significant reduction of InAs native oxides after different treatments. The capacitance-voltage C-V characterization of Al(2)O(3)/n-InAs structures shows that the frequency dispersion in the accumulation regime is small (< 0.75%/dec) and does not seem to be significantly affected by the different surface treatments, whereas the latter improves depletion and inversion behaviors of the n-channel metal-oxide-semiconductor capacitors. The interface trap density profiles extracted from the simulation mainly show donorlike interface states inside the InAs band gap and in the lower part of the conduction band. The donorlike traps inside the InAs band gap and in the lower part of the conduction band were significantly reduced by using wet-chemical-plus-TMA treatments, in agreement with C-V characteristics.
Electrical Characterization of Al2O3/n-InAs Metal-Oxide-Semiconductor Capacitors With Various Surface Treatments
(2011-06-01)
Trinh, H. D.
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Brammertz, G.
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Chang, E. Y.
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Kuo, C. I.
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Lu, C. Y.
Ex situ sulfide and HCl wet chemical treatments in conjunction with in situ trimethyl aluminum (TMA) pretreatment were performed before the deposition of Al2O3 on n-InAs surfaces. X-ray photoelectron spectroscopy analyses show a significant reduction of InAs native oxides after different treatments. The capacitance-voltage C-V characterization of Al2O3/n-InAs structures shows that the frequency dispersion in the accumulation regime is small (< 0.75%/dec) and does not seem to be significantly affected by the different surface treatments, whereas the latter improves depletion and inversion behaviors of the n-channel metal-oxide-semiconductor capacitors. The interface trap density profiles extracted from the simulation mainly show donorlike interface states inside the InAs band gap and in the lower part of the conduction band. The donorlike traps inside the InAs band gap and in the lower part of the conduction band were significantly reduced by using wet-chemical-plus-TMA treatments, in agreement with C-V characteristics.
Enhancement-Mode GaN MIS-HEMTs with HfLaOx Gate Insulator
(2016)
Lin, Y. C.
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Lin, J. C.
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Lin, Y.
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Wu, C. H.
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Huang, Y. X.
Evaluation of GaN HEMT with Field Plate for Reliability Improvement
(2016)
Lin, Y. C.
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Lin, J. C.
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Lin, Y.
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Wu, C. H.
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Chin, P. C.
Evaluation of the characteristics of the microelectrical discharge machining process using response surface methodology based on the central composite design
(2012-10-01)
Lin, Y. C.
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Tsao, C. C.
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Hsu, C. Y.
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Hung, S. K.
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Wen, D. C.
Evaluation of the characteristics of a microelectrical discharge machining (Micro-EDM) process is challenging, because it involves complex, interrelated relationships so a proper modeling approach is necessary to clearly identify the crucial machining variables and their interrelationships in order to initiate more effective strategies to improve Micro-EDM qualities (electrode wear (EW), material removal rate (MRR) and overcut). This paper uses a response surface method (RSM) based on the central composite design (CCD) for Micro-EDM problems with four EDM variables (peak current, pulse on-time, pulse off-time and electrode rotation speed). Experimental results indicate that peak current is the EDM variable that most affects the Micro-EDM qualities for SK3 carbon tool steel while pulse off-time had a significant interaction with that. The results show that RSM based on the CCD could efficiently be applied for the modeling of Micro-EDM qualities (EW, MRR, and overcut), and it is an economical way to obtain the performance characteristics of Micro-EDM process parameters with the fewest experimental data.
Extreme Hyperlactatemia After Heart Transplantation: One Center's Experience
(2015-07-01)
Hsu, Y. C.
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Hsu, C. H.
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Huang, G. S.
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Lu, C. C.
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Wu, Z. F.
Introduction. Hyperlactatemia may occur early after cardiac surgery and is correlated with prognosis. This study was conducted to analyze the perioperative variables and postoperative outcomes among heart transplant recipients with extremely high lactate levels (>15 mmol/L). Methods. The single-center medical records of heart transplantation from June 2006 to May 2013 were retrospectively reviewed for patient characteristics, perioperative hemodynamic variables, arterial blood gas analysis data, and postoperative mortality. Results. Among 58 consecutive heart transplant recipients, lactate levels over the detectable upper limit (>15 mmol/L) were identified in 12 patients after intensive care unit admission, with peak time at 1.9 +/- 2.0 (range 0-6.1) hours. The maximal preoperative lactate level was 3.1 mmol/L, and most (11/12) postoperative lactate levels returned to <4 mmol/L at 27.5 +/- 12.8 hours after surgery (range 15-58, median 24), displaying a trend toward delayed extubation time in 10 recipients (P < .01). Blood glucose levels elevated significantly from preoperative 148.9 +/- 45.2 to 375.7 +/- 96.9 mg/dL at peak lactate level (P < .01). Four patients died in the ICU (range 5-32 days), 4 died after discharge (range 5-57 months), with 6 in total surviving over 1 year. Conclusion. Extreme hyperlactatemia commonly occurred early after heart transplantation and mostly recovered within 30 hours; however, with delayed extubation time after operation.
First Experimental Demonstration of Negative Capacitance InGaAs MOSFETs With Hf0.5Zr0.5O2 Ferroelectric Gate Stack
(2018-01-01)
Luc, Q. H.
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Fan-Chiang, C. C.
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Huynh, S. H.
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Huang, P.
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Do, H. B.
We demonstrate, for the first time, the negative capacitance (NC) In0.53Ga0.47As nMOSFET with 8-nm Hf0.5Zr0.5O2 (HZO) as ferroelectric (FE) dielectric for sub-60 mV/dec subthreshold swing (SS). The impact of annealing treatments on the FE properties and electrical characteristics of NC InGaAs nMOSFETs are investigated. Optimized annealing condition results in NC effects at the HZO/Al2O3/InGaAs nMOSFETs with steep SS property (similar to 11 mV/dec).