Browsing by Issue Date, starting with "2010-04-12"

Now showing 1 - 20 of 46404

High color rendering white light-emitting-diode illuminator using the red-emitting Eu(2+)-activated CaZnOS phosphors excited by blue LED
(2010-04-12)
Kuo, Te-Wen
;
Liu, Wei-Ren
;
Chen, Teng-Ming
;
應用化學系
;
Department of Applied Chemistry
A red phosphor CaZnOS:Eu(2+) was synthesized by solid state reaction and has been evaluated as a candidate for white LEDs. For this material, the XRD, PL, PL excitation (PLE) and diffuse reflection spectra have also been investigated. CaZnOS:Eu(2+) reveals a broad absorption band and good color purity. By utilizing a mixture of red-emitting CaZnOS:Eu(2+), green-emitting (Ba,Sr)(2)SiO(4):Eu(2+) and yellow-emitting Y(3)Al(5)O(12):Ce(3+) as light converters, an intense white InGaN-based blue-LED (similar to 460 nm) was fabricated to exhibit a high color-rendering index Ra of 85 at a correlated color temperature of 4870 K. Based on the results, we are currently evaluating the potential application of CaZnOS:Eu(2+) as a red-emitting blue-chip convertible phosphor. (c) 2010 Optical Society of America
Embedded indium-tin-oxide nanoelectrodes for efficiency and lifetime enhancement of polymer-based solar cells
(2010-04-12)
Yu, Peichen
;
Chang, Chia-Hua
;
Su, Ming-Shin
;
Hsu, Min-Hsiang
;
Wei, Kung-Hwa
In this paper, distinctive indium-tin-oxide (ITO) nanorods are employed to serve as buried electrodes for polymer-based solar cells. The embedded nanoelectrodes allow three-dimensional conducting pathways for low-mobility holes, offering a highly scaffolded cell architecture in addition to bulk heterojunctions. As a result, the power conversion efficiency of a polymer cell with ITO nanoelectrodes is increased to about 3.4% and 4.4% under one-sun and five-sun illumination conditions, respectively, representing an enhancement factor of up to similar to 10% and 36% compared to a conventional counterpart. Also, the corresponding device lifetime is prolonged twice as much to about 110 min under five-sun illumination.
High color rendering white light-emitting-diode illuminator using the red-emitting Eu2+-activated CaZnOS phosphors excited by blue LED
(2010-04-12)
Kuo, Te-Wen
;
Liu, Wei-Ren
;
Chen, Teng-Ming
;
應用化學系
;
Department of Applied Chemistry
A red phosphor CaZnOS:Eu2+ was synthesized by solid state reaction and has been evaluated as a candidate for white LEDs. For this material, the XRD, PL, PL excitation (PLE) and diffuse reflection spectra have also been investigated. CaZnOS:Eu2+ reveals a broad absorption band and good color purity. By utilizing a mixture of red-emitting CaZnOS:Eu2+, green-emitting (Ba,Sr)(2)SiO4:Eu2+ and yellow-emitting Y3Al5O12:Ce3+ as light converters, an intense white InGaN-based blue-LED (similar to 460 nm) was fabricated to exhibit a high color-rendering index Ra of 85 at a correlated color temperature of 4870 K. Based on the results, we are currently evaluating the potential application of CaZnOS:Eu2+ as a red-emitting blue-chip convertible phosphor. (c) 2010 Optical Society of America
Ultraviolet GaN-based microdisk laser with AlN/AlGaN distributed Bragg reflector
(2010-04-12)
Chen, Cheng-Chang
;
Shih, M. H.
;
Yang, Yi-Chun
;
Kuo, Hao-Chung
;
光電工程學系
We demonstrated a 4.7 mu m GaN-based microdisk laser with 25-pair AlN/AlGaN distributed Bragg reflector in ultraviolet range without undercut or deeply-etching procedures. The distributed Bragg reflector provides a high reflectivity of 85%, and selects lasing mode around 375 nm wavelength. Under optical pumping conditions, the lasing action was observed with a low threshold power density of 0.03 kW/cm(2). We also characterized the whispering gallery mode profiles of the microdisk with finite-different time-domain simulation.
Digital loop filter for all-digital phase-locked loop design
(2010-04-13)
Lee
;
Chen-yi
;
Chung
;
Ching-che
A digital loop filter installed in an all-digital phase-locked loop (PLL) receives a digitally controlled oscillator (DCO) control code transmitted from a PLL controller in the all-digital PLL, and calculate an average value, such that the PLL controller can produce another DCO control code by the average value for controlling and adjusting an output signal of a digitally controlled oscillator (DCO) in the neighborhood of the average value to maintain compensating a phase/frequency difference with an input signal, so as to minimize the jitter effect of the input signal on the all-digital PLL, reduce the jitter effect of the output signal, and keep tracking and locking the frequency and the phase of the input signal.
Transmission of Wireless and Wired Services Employing a Simple System Architecture
(2010-04-15)
Jiang, Wen-Jr
;
Lin, Chun-Ting
;
Shih, Po-Tsung
;
Chen, Yu-Hung
;
Chen, Jason (Jyehong)
This letter presents a novel modulation approach for simultaneous generation and transmission of optical radio-frequency (RF) wireless vector signal and baseband (BB) wireline signal using a single-electrode Mach-Zehnder modulator. Based on a double sideband with carrier suppression scheme and properly predistorted driving vector signal, a 2.5-Gb/ s quadrature phase-shift keying (QPSK) signal at 60 GHz is generated with a 1.25-Gb/ s BB ON-OFF-keying (OOK) signal. The proposed system can carry higher spectral efficiency vector signals and needs no optical filter to separate the BB and RF signals at remote nodes. Moreover, optical RF signal generation with frequency doubling is also achieved to reduce the bandwidth requirement of the transmitter. After transmission over 25-km single-mode fiber, the power penalties of the generated QPSK and OOK signals are about 4 and 0.1 dB, respectively.
Digital Loop Filter for All-Digital Phase-Locked Loop Design
(2010-04-15)
Lee, Chen-yi
;
Chung, Ching-che
A digital loop filter installed in an all-digital phase-locked loop (PLL) receives a digitally controlled oscillator (DCO) control code transmitted from a PLL controller in the all-digital PLL, and calculate an average value, such that the PLL controller can produce another DCO control code by the average value for controlling and adjusting an output signal of a digitally controlled oscillator (DCO) in the neighborhood of the average value to maintain compensating a phase/frequency difference with an input signal, so as to minimize the jitter effect of the input signal on the all-digital PLL, reduce the jitter effect of the output signal, and keep tracking and locking the frequency and the phase of the input signal.
Enhancing ATP-based bacteria and biofilm detection by enzymatic pyrophosphate regeneration
(2010-04-15)
Lee, Hui-Ju
;
Ho, Ming-Rong
;
Bhuwan, Manish
;
Hsu, Ching-Yi
;
Huang, Meng-Shun
The manufacturing processes of many electronic and medical products demand the use of high-quality water. Hence the water supply systems for these processes are required to be examined regularly for the presence of microorganisms and microbial biofilms. Among commonly used bacteria detection approaches, the ATP luminescence assay is a rapid, sensitive, and easy to perform method. The aim of this study is to investigate whether ATP regeneration from inorganic pyrophosphate, a product of the ATP luminescence assay, can stabilize the bioluminescence signals in ATP detection. ADPglc pyrophosphorylase (AGPPase), which catalyzes the synthesis of ATP from PP(i) in the presence of ADPglc, was selected because the system yields much lower luminescence background than the commercially available ATP sulfurylase/adenosine 5'-phosphosulfate (APS) system which was broadly used in pyrosequencing technology. The AGPPase-based assay could be used to measure both PPi and ATP quantitatively and shows 1.5- to 4.0-fold slight increases in a 10-min assay. The method could also be used to stabilize the luminescence signals in detection of Escherichia coli, Pseudo monas aeruginosa, and Bacillus cereus in either broth or biofilm. These findings suggest that the AGPPase-based ATP regeneration system will find many practical applications such as detection of bacterial biofilm in water pipelines. (C) 2009 Elsevier Inc. All rights reserved.
Switching kinetics in epitaxial BiFeO(3) thin films
(2010-04-15)
Pantel, Daniel
;
Chu, Ying-Hao
;
Martin, Lane W.
;
Ramesh, Ramamoorthy
;
Hesse, Dietrich
The switching kinetics in epitaxial (001)-, (110)-, and (111)-oriented BiFeO(3) thin films were investigated as a function of applied field and time. It was found that the ferroelectric switching behavior obeys the Kolmogorov-Avrami-Ishibashi theory only in the high field range. The detailed behavior depends on the film orientation. A comparison with standard systems, such as epitaxial Pb(Zr(0.2)Ti(0.8))O(3) films, reveals some similarities as well as some differences. For instance, the presence of 109 degrees and 71 degrees ferroelastic domain walls might be ruled out as the source of the decrease in switched polarization at low applied fields, in contrast to what is the case for a/c domain walls in tetragonal Pb(Zr(0.2)Ti(0.8))O(3). (C) 2010 American Institute of Physics. [doi:10.1063/1.3392884]
Epitaxial growth of ZnO films at extremely low temperature by atomic layer deposition with interrupted flow
(2010-04-15)
Ku, Ching-Shun
;
Lee, Hsin-Yi
;
Huang, Jheng-Ming
;
Lin, Chih-Ming
;
材料科學與工程學系
Thin crystalline films of zinc oxide (ZnO) of high quality have been grown epitaxially on a (0 0 0 1) c-plane of a sapphire substrate with atomic layer deposition (ALD) at extra-low temperature. With diethylzinc (DEZn) and deionized water as precursors in combination with interrupted flow, we obtained ZnO thin films with an optimal growth window in a range 25-160 degrees C, so effectively lowering the growth temperature by about 120 degrees C relative to the conventional method involving a continuous-flow. We characterized the microstructure of these films with X-ray reflectivity and high-resolution X-ray diffraction (XRD) measurements. The XRD results indicate that the stock time might extend the reaction of DEZn and water through an increased duration. This low temperature for growth results in increased crystalline quality and reduced the non-radiative recombination process to enhance the optical properties of ZnO films. (c) 2009 Elsevier B.V. All rights reserved.
GLOVE PUPPET MANIPULATING SYSTEM
(2010-04-15)
HU, Jwu-Sheng
;
Wang, Jyun-Ji
;
Sun, Guan-Qun
;
Tang, Chi-Him
A glove puppet manipulating system comprises a control module for generating control signals base on movements of human hand and a robot electrically connecting the control module installed inside a glove puppet. The robot has a body manipulating apparatus disposed on a foundation to manipulate the body of the glove puppet to rotate, a pair of hand manipulating apparatuses disposed on the body manipulating apparatus to manipulate the hands of the glove puppet to swivel, and a head manipulating apparatus interposed between the hand manipulating apparatuses on the body manipulating apparatus to manipulate the head of the glove puppet to nod.
The effect of carrier mobility in organic solar cells
(2010-04-15)
Shieh, Ji-Ting
;
Liu, Chiou-Hua
;
Meng, Hsin-Fei
;
Tseng, Shin-Rong
;
Chao, Yu-Chiang
The microscopic states and performance of organic solar cell are investigated theoretically to explore the effect of the carrier mobility. With Ohmic contacts between the semiconductor and the metal electrodes there are two origins of carriers in the semiconductor: the photocarriers generated by photon absorption and the dark carriers diffused from the electrodes. The power efficiency of the solar cell is limited by the recombination of a carrier with either the photocarrier or a dark carrier. Near the short-circuit condition the photocarrier recombination in the semiconductor bulk decreases as the mobility increases. Near the open-circuit condition the dark carrier recombination increases with the mobility. These two opposite effects balance with one another, resulting in an optimal mobility about 10(-2) cm(2)/V s which gives the highest power conversion efficiency. The balance of the electron and hole mobilities are not necessary to maintain the optimal efficiency also because of the balance of the photocarrier and dark carrier recombination. The efficiency remains about the same as one carrier mobility is fixed at 10(-2) cm(2)/V s while the other one varies from 10(-1) to 10(-3) cm(2)/V s. For solar cell with a Schottky barrier between the semiconductor and the metal electrode there is no dark carrier recombination. The efficiency therefore always increases with the mobility. (C) 2010 American Institute of Physics. [doi: 10.1063/1.3327210]
The synthesis of diamond films on adamantane-coated Si substrate at low temperature
(2010-04-15)
Tiwari, Rajanish N.
;
Tiwari, Jitendra N.
;
Chang, Li
;
材料科學與工程學系
;
Department of Materials Science and Engineering
Diamond films have been synthesized on the adamantane-coated Si (1 00) substrate by microwave plasma chemical vapor deposition from a gaseous mixture of methane and hydrogen gases with a growth rate of similar to 6.7 nm/min. The substrate temperature was similar to 475 degrees C during diamond deposition. The films obtained have good crystallinity that is characterized by scanning electron microscopy and Raman spectrometry. X-ray photoelectron spectroscopy analysis has confirmed that diamond nucleation and growth are on SiC rather than clean Si. The possible mechanism of high rate growth diamond films has been demonstrated. (C) 2010 Elsevier B.V. All rights reserved.
Switching kinetics in epitaxial BiFeO3 thin films
(2010-04-15)
Pantel, Daniel
;
Chu, Ying-Hao
;
Martin, Lane W.
;
Ramesh, Ramamoorthy
;
Hesse, Dietrich
The switching kinetics in epitaxial (001)-, (110)-, and (111)-oriented BiFeO3 thin films were investigated as a function of applied field and time. It was found that the ferroelectric switching behavior obeys the Kolmogorov-Avrami-Ishibashi theory only in the high field range. The detailed behavior depends on the film orientation. A comparison with standard systems, such as epitaxial Pb(Zr0.2Ti0.8)O-3 films, reveals some similarities as well as some differences. For instance, the presence of 109 degrees and 71 degrees ferroelastic domain walls might be ruled out as the source of the decrease in switched polarization at low applied fields, in contrast to what is the case for a/c domain walls in tetragonal Pb(Zr0.2Ti0.8)O-3. (C) 2010 American Institute of Physics. [doi:10.1063/1.3392884]
VIRTUAL INPUT SYSTEM AND METHOD
(2010-04-15)
Lee, Chia Hoang
;
Chen, Yi An
The invention provides a virtual input system. The virtual input system comprises a trajectory generating apparatus and a receiving apparatus. The receiving apparatus comprises a sensing module, a coding module, a database, and a comparing module. The sensing module is used for sensing a trajectory information of the trajectory generating apparatus. The coding module converts the trajectory information to a specific code series according to a coding rule. The database stores a plurality of reference code series and a plurality of reference symbols corresponding to the plurality of reference code series. The comparing module compares the specific code series with the plurality of reference code series to determine at least one candidate symbol from the plurality of reference symbols.
掌中戲戲偶操控系統
(2010-04-16)
胡竹生
;
王俊吉
;
孫冠群
;
鄧智謙
掌中戲戲偶操控系統藉由自動化控制的方式操作戲偶，具有控制模組和戲偶操作裝置。控制模組根據人手運動產生控制訊號。戲偶操作裝置裝設於戲偶內且電性連接控制模組。戲偶操作裝置的身體操控機構固定於基座上且連接戲偶軀幹，以根據控制訊號操控軀幹相對於基座旋轉。頭部操控機構固定於身體操控機構上且連接戲偶之頭部，以根據控制訊號操控頭部相對於軀幹彎折。一對手部操控機構固定於身體操控機構上且在頭部操控機構之兩側，連接戲偶之手部，以根據控制訊號操控戲偶的雙手相對於軀幹彎折。
用於全數位鎖相迴路設計之數位濾波器
(2010-04-16)
李鎮宜
;
鍾菁哲
本發明係揭示一種數位濾波器，其係裝設在一全數位鎖相迴路中，該數位濾波器係接收該全數位鎖相迴路中之一鎖相迴路控制器，所傳送之一震盪器控制碼，並計算出一平均值，使該鎖相迴路控制器可藉由該平均值而產生一另一震盪器控制碼，藉以控制並調整數位控制震盪器之一輸出端訊號保持在該平均值附近，進而持續的補償與該輸入端訊號間的相位差/頻率差，可進一步減少該輸入端訊號之抖動對該全數位鎖相迴路之影響，及有效的降低該輸出端訊號之抖動現象，且可保持對該輸入端訊號頻率及相位的追蹤及鎖定。
虛擬輸入系統及方法
(2010-04-16)
李嘉晃
;
陳奕安
本發明提供一種虛擬輸入系統。該虛擬輸入系統包含軌跡產生裝置及接收裝置。該接收裝置包含感測模組、編碼模組、資料庫及比對模組。感測模組係用以感測軌跡產生裝置之軌跡資訊。編碼模組係根據編碼規則將軌跡資訊編碼成特定代碼串列。資料庫儲存有複數個參考代碼串列及對應於該複數個參考代碼串列之複數個參考符號。比對模組根據特定代碼串列與複數個參考代碼串列自複數個參考符號中決定至少一候選符號。
光學式觸控顯示裝置、光學式觸控感測裝置以及觸控位置計算方法
(2010-04-16)
曾斌誠
;
田仲豪
本發明係提供一種光學式觸控顯示裝置、光學式觸控感測裝置以及一種觸控位置計算方法，其中光學式觸控感測裝置以可拆卸方式或黏貼方式裝設於一顯示面板之上。本發明包含第一光源、第二光源、光學感測元件以及處理元件。當一物體阻擋光線之行進時，部分光學感測元件將部分接收或甚至完全無法收到光線。處理元件將根據該等光學感測元件、第一光源以及第二光源之位置計算出兩條交叉之線段，之後將定義該等線段之相交點為物體之位置或觸控輸入發生之點。
浸入式傾斜微影機台及其浸入槽
(2010-04-16)
洪國永
;
曾繁根
一種用於浸入式傾斜微影製程的浸入槽。浸入槽的殼體具有底板和數個側壁彼此緊密接合且包圍形成一容置空間。側壁上有貫穿側壁的軸承孔。容置空間中填充液體，液體的折射率介於1.4到1.8之間。載台位於容置空間中且浸埋於液體中。載台的一側具有一軸。軸穿過軸承孔且軸的方向平行於底板。在殼體之外緊鄰軸承孔之處設有旋轉機構。旋轉機構連接穿出軸承孔外的軸。當旋轉機構旋轉軸時，進而帶動載台旋轉，使得載台傾斜。