Browsing by Author "Chen, Yu-Lin"

Now showing 1 - 8 of 8

A 40-nm-Gate InAs/In(0.7)Ga(0.3)As Composite-Channel HEMT with 2200 mS/mm and 500-GHz f(T)
(2009)
Kuo, Chien-I
;
Hsu, Heng-Tung
;
Wu, Chien-Ying
;
Chang, Edward Yi
;
Miyamoto, Yasuyuki
A 40-nm T-gate high-electron-mobility-transistor with InAs/In(0.7)Ga(0.3)As composite-channel has been fabricated. The device exhibits a transconductance (g.) of 2200 mS/mm, a cutoff frequency f(T) of 506 GHz and a minimum noise figure of 1.21 dB at a frequency of 58 GHz. These performances make the device well-suited for millimeter-wave or sub-millimeter-wave applications.
A general analytical solution for flow to a single horizontal well by Fourier and Laplace transforms
(2011-05-01)
Huang, Ching-Sheng
;
Chen, Yu-Lin
;
Yeh, Hund-Der
;
環境工程研究所
;
Institute of Environmental Engineering
The objective of this paper is to present an analytical solution for describing the head distribution in an unconfined aquifer with a single pumping horizontal well parallel to a fully penetrating stream. The Laplace-domain solution is developed by applying Fourier sine, Fourier and Laplace transforms to the governing equation as well as the associated initial and boundary conditions. The time-domain solution is obtained after taking the inverse Laplace transform along with the Bromwich integral method and inverse Fourier and Fourier sine transforms. The upper boundary condition of the aquifer is represented by the free surface equation in which the second-order slope terms are neglected. Based on the solution and Darcy's law, the equation representing the stream depletion rate is then derived. The solution can simulate head distributions in an aquifer infinitely extending in horizontal direction if the well is located far away from the stream. In addition, the solution can also simulate head distributions in confined aquifers if specific yield is set zero. It is shown that the solution can be applied practically to evaluate flow to a horizontal well. (C) 2011 Elsevier Ltd. All rights reserved.
Au-Cd1-xZnxS core-alloyed shell nanocrystals: boosting the interfacial charge dynamics by adjusting the shell composition
(2018-09-28)
Pu, Ying-Chih
;
Chen, Wei-Ta
;
Fang, Mei-Jing
;
Chen, Yu-Lin
;
Tsai, Kai-An
Au-Cd1-xZnxS core-shell nanocrystals (NCs) with controllable shell compositions (from x = 0 to x = 0.37) were synthesized by using the hot-injection method. By increasing the mole fraction of ZnS in the Cd1-xZnxS shell, the conduction band of Cd1-xZnxS can be cathodically shifted to cause an increase of energy difference between the conduction band level of the Cd1-xZnxS shell and the Fermi level of the Au core, thereby enlarging the driving force of interfacial electron transfer to enhance the photoelectrochemical (PEC) efficiency. The interfacial charge dynamics of the samples were examined by time-resolved photoluminescence (TRPL) spectroscopy. The results showed that the interfacial electron transfer rate constant (k(et)) from the Cd1-xZnxS shell to the Au core was increased by 2 orders of magnitude, from 2.41 x 10(7) to 4.91 x 10(9) s(-1) as the mole fraction of ZnS increased from 0 to 0.37. Furthermore, PEC characterization, including Mott-Schottky analysis and photovoltage decay measurements, illustrated that gradually introducing ZnS into the shell composition of Au-Cd1-xZnxS NCs can modify the band structure and enhance the effectiveness of interfacial ET for advancing the PEC properties. The practical use of Au-Cd1-xZnxS NCs in PEC methanol oxidation was also demonstrated, revealing their promising potential as viable photoelectrodes for various PEC applications. The present study delivers an alternative approach of modulating the interfacial ET dynamics of core-shell MSNs by means of shell composition adjustment. The illustrations provide an empirical guideline to the intelligent design of core-shell metal-semiconductor nanoheterostructures (MSNs) for the desired PEC applications.
DC and RF Performance Improvement of 70 nm Quantum Well Field Effect Transistor by Narrowing Source-Drain Spacing Technology
(2010)
Kuo, Chien-I
;
Hsu, Heng-Tung
;
Chang, Edward Yi
;
Miyamoto, Yasuyuki
;
Wu, Chien-Ying
A 70 nm InAs channel quantum well field effect transistor (QWFET) fabricated by a narrowing source-drain (S/D) spacing technique was realized for future high-speed and logic applications. The S/D spacing was decreased from 3 to 0.65 mu m through a simple fabrication process, which is an ameliorative redeposition ohmic technique. The drain-source current density and transconductance of the device were increased from 391 to 517 mA/mm and from 946 to 1348 mS/mm after the scaling of the S/D spacing, respectively. In addition, the current gain cutoff frequency (f(T)) was also increased from 185 to 205 GHz. These results show that the easy method can effectively improve the III-V QWFET device performance for high-frequency and high-speed applications. (C) 2010 The Japan Society of Applied Physics
Improvement in RF performance of 40-nm InAs-channel based HEMTs using Pt gate sinking with two-step recess processes technology
(2010-12-01)
Kuo, Chien-I
;
Hsu, Heng-Tung
;
Wu, Chien-Ying
;
Chang, Edward Y.
;
Chen, Yu-Lin
Forty-nanometer lnAs HEMT devices fabricated by two-step recess and Pt-buried gate were demonstrated for low-noise and low-power millimeter wave applications. The device exhibited a high transconductance of 1650 mS/mm at a drain voltage of 0.5 V. Improvement of the current-gain cutoff frequency from 395 GHz to 423 GHz was achieved with minimum noise figure below 2.5 dB up to 64 GHz at only 4.33 mW DC power consumption level. Besides, the output conductance was decreased from 2400 mS/ mm to 325 mS/mm. These superior performances are attributed to mitigation of the short-channel effect through the proposed technology. (C) 2010 Elsevier B.V. All rights reserved.
RF Performance Improvement of Metamorphic High-Electron Mobility Transistor Using (In(x)Ga(1-x)As)(m)/(InAs)(n) Superlattice-Channel Structure for Millimeter-Wave Applications
(2010-07-01)
Kuo, Chien-I
;
Hsu, Heng-Tung
;
Chen, Yu-Lin
;
Wu, Chien-Ying
;
Chang, Edward Yi
High-performance metamorphic high-electron mobility transistors (MHEMTs) using an (In(x)Ga(1-x)As)(m)/(InAs)(n) superlattice structure as a channel layer have been fabricated successfully. These HEMTs with 80-nm gate length exhibited a high drain current density of 392 mA/mm and a transconductance of 991 mS/mm at 1.2-V drain bias. Compared with a regular In(x)Ga(1-x)As channel, the superlattice-channel HEMTs showed an outstanding performance due to the high electron mobility and better carrier confinement in the (In(x)Ga(1-x)As)(m)/(InAs)(n) channel layer. When biased at 1.2 V, the current gain cutoff frequency (f(T)) and the maximum oscillation frequency (f(max)) were extracted to be 304 and 162 GHz, respectively. As for noise performance, the device demonstrated a 0.75-dB minimum noise figure(NF(min)) with an associated gain of 9.6 dB at 16 GHz. Such superior performance has made the devices with a superlattice channel well suitable for millimeter-wave applications.
RF Performance Improvement of Metamorphic High-Electron Mobility Transistor Using (InxGa1-xAs)(m)/(InAs)(n) Superlattice-Channel Structure for Millimeter-Wave Applications
(2010-07-01)
Kuo, Chien-I
;
Hsu, Heng-Tung
;
Chen, Yu-Lin
;
Wu, Chien-Ying
;
Chang, Edward Yi
High-performance metamorphic high-electron mobility transistors (MHEMTs) using an (InxGa1-xAs)(m)/(InAs)(n) superlattice structure as a channel layer have been fabricated successfully. These HEMTs with 80-nm gate length exhibited a high drain current density of 392 mA/mm and a transconductance of 991 mS/mm at 1.2-V drain bias. Compared with a regular InxGa1-xAs channel, the superlattice-channel HEMTs showed an outstanding performance due to the high electron mobility and better carrier confinement in the (InxGa1-xAs)(m)/(InAs)(n) channel layer. When biased at 1.2 V, the current gain cutoff frequency (f(T)) and the maximum oscillation frequency (f(max)) were extracted to be 304 and 162 GHz, respectively. As for noise performance, the device demonstrated a 0.75-dB minimum noise figure(NFmin) with an associated gain of 9.6 dB at 16 GHz. Such superior performance has made the devices with a superlattice channel well suitable for millimeter-wave applications.
Smart Interactive Education System Based on Wearable Devices
(2019-08-01)
Liang, Jia-Ming
;
Su, Wei-Cheng
;
Chen, Yu-Lin
;
Wu, Shih-Lin
;
Chen, Jen-Jee
Due to the popularity of smart devices, traditional one-way teaching methods might not deeply attract school students' attention, especially for the junior high school students, elementary school students, or even younger students, which is a critical issue for educators. Therefore, we develop an intelligent interactive education system, which leverages wearable devices (smart watches) to accurately capture hand gestures of school students and respond instantly to teachers so as to increase the interaction and attraction of school students in class. In addition, through multiple physical information of school students from the smart watch, it can find out the crux points of the learning process according to the deep data analysis. In this way, it can provide teachers to make instant adjustments and suggest school students to achieve multi-learning and innovative thinking. The system is mainly composed of three components: (1) smart interactive watch; (2) teacher-side smart application (App); and (3) cloud-based analysis system. Specifically, the smart interactive watch is responsible for detecting the physical information and interaction results of school students, and then giving feedback to the teachers. The teacher-side app will provide real-time learning suggestions to adjust the teaching pace to avoid learning disability. The cloud-based analysis system provides intelligent learning advices, academic performance prediction and anomaly learning detection. Through field trials, our system has been verified that can potentially enhance teaching and learning processes for both educators and school students.