Browsing by Issue Date, starting with "2010-12-06"

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Effect of substrate misorientation on the material properties of GaAs/Al(0.3)Ga(0.7)As tunnel diodes
(2010-12-06)
Yu, H. W.
;
Chang, E. Y.
;
Nguyen, H. Q.
;
Chang, J. T.
;
Chung, C. C.
The effect of substrate misorientation on the material quality of the N(++)-GaAs/P(++)-AlGaAs tunnel diodes (TDs) grown on these substrates is investigated. It is found that the misorientation influences both surface roughness and interface properties of the N(++)-GaAs/P(++)-AlGaAs TDs. Smooth surface (rms roughness: 1.54 angstrom) and sharp interface for the GaAs/Al(0.3)Ga(0.7)As TDs were obtained when the (100) tilted 10 degrees off toward [111] GaAs substrate was used. Besides, the oxygen content in N(++)-GaAs and P(++)-AlGaAs layers grown on the 10 degrees off GaAs substrates was reduced due to the reduction of sticking coefficient and number of anisotropic sites. (C) 2010 American Institute of Physics. [doi:10.1063/1.3525158]
40-Gb/s downstream DPSK and 40-Gb/s upstream OOK signal remodulation PON using reduced modulation index
(2010-12-06)
Chow, C. W.
;
Yeh, C. H.
;
光電工程學系
;
Department of Photonics
As different high speed signal-remodulation wavelength division multiplexed - passive optical network (WDM-PON) solutions up to 10 Gb/s have been proposed, researchers are going to further increase the data rate of PON towards 40 Gb/s or higher. However, scaling up from 10 Gb/s/wavelength to 40 Gb/s/wavelength PON is very challenging. Although many studies have been performed on upgrading the exiting 10 Gb/s network to 40 Gb/s, the study of the 40 Gb/s signal-remodulation network is very little. In this work, we will first study the chromatic dispersion effect on the signal-remodulation PON. Then, we will propose and demonstrate a signal-remodulation PON using 40-Gb/s downstream differential-phase shift keying (DPSK) and 40-Gb/s upstream on-off keying (OOK) signals. By using the reduced modulation index (RMI) of the downstream DPSK signal, the tolerance to the residual chromatic dispersion of the whole system can be greatly enhanced. Due to the reduced impact of the accumulated chromatic dispersion, the quality of the upstream remodulated OOK signal can be significantly improved. Besides, by detecting the downstream demodulated DPSK signal at the destructive output port of the demodulator, good quality of the demodulated DPSK signal can still be achieved. (C) 2010 Optical Society of America
Selective Oxygen-Plasma-Etching Technique for the Formation of ZnO-FTO Heterostructure Nanotubes and Their Rectified Photocatalytic Properties
(2010-12-06)
Chantarat, N.
;
Chen, Yu-Wei
;
Lin, Chin-Ching
;
Chiang, Mei-Ching
;
Chen, San-Yuan
A novel ZnO-FTO heterostructure nanotube array was produced by combining a chemical solution process with oxygen-plasma etching. In this approach, presynthesized ZnO nanorod arrays act as templates, and FTO nanoparticles are deposited onto the ZnO nanorods by a simple spray pyrolysis method. X-ray photoelectron spectroscopy analysis demonstrated that the oxygen-plasma treatment decreased the O(2-)/OH(-) concentration ratio, resulting in dissociation of the Zn-O bonds and the outward diffusion of Zn cations to form an interior hollow, which is related to the formation of the hydroxyl functional group, Sn-OH, at the FTO surface. An etching evolution mechanism of the ZnO-FTO nanotubes via oxygen plasma was tentatively proposed in this study. Time-dependent photocurrent (I-T) measurements under ON-OFF cycles of UV illumination confirm that the 20-min etched sample exhibits a rectified photoresponse characteristic and a dark current increased by about 3 orders of magnitude over that of the unetched sample, which is attributed to the increased carrier concentration created at the surface conductive layer. This investigation offers an alternative selective etching method to lay the framework for nanoscale three-dimensional electrodes for solar-cell applications.
Effect of substrate misorientation on the material properties of GaAs/Al0.3Ga0.7As tunnel diodes
(2010-12-06)
Yu, H. W.
;
Chang, E. Y.
;
Nguyen, H. Q.
;
Chang, J. T.
;
Chung, C. C.
The effect of substrate misorientation on the material quality of the N++-GaAs/P++-AlGaAs tunnel diodes (TDs) grown on these substrates is investigated. It is found that the misorientation influences both surface roughness and interface properties of the N++-GaAs/P++-AlGaAs TDs. Smooth surface (rms roughness: 1.54 angstrom) and sharp interface for the GaAs/Al0.3Ga0.7As TDs were obtained when the (100) tilted 10 degrees off toward [111] GaAs substrate was used. Besides, the oxygen content in N++-GaAs and P++-AlGaAs layers grown on the 10 degrees off GaAs substrates was reduced due to the reduction of sticking coefficient and number of anisotropic sites. (C) 2010 American Institute of Physics. [doi:10.1063/1.3525158]
Optical properties of light emitting diodes with a cascading plasmonic grating
(2010-12-06)
Wang, Chih-Ming
;
Tsai, Yao-Lin
;
Tu, Sheng-Han
;
Lee, Chien-Chieh
;
Kuo, Cheng-Huang
In this paper, the polarization dependent optical properties of InGaN/GaN multi-quantum wells (MQWs) LED with cascading plasmonic gratings are investigated using an angle-resolved photoluminescence (ARPL) spectrometer. The plasmonic gratings consist of two Ag gratings with a half-pitch displacement. The ARPL spectra of the TE-TM state present a broadband emission with resonance dips occasioned by the SP resonance while the TM-TE state presents resonance peaks with low sideband emission. The resonance properties can be tuned by modifying the geometric parameters of the plasmonic grating. The ARPL spectrum of the LED sample with pure GaN 1D grating is also measured and discussed. The investigated plasmonics LED represents resonance optical properties different from the conventional surface relief LED, which can be used in special applications. (C) 2010 Optical Society of America
Square lattice photonic crystal surface mode lasers
(2010-12-06)
Lu, Tsan-Wen
;
Lu, Shao-Ping
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Chiu, Li-Hsun
;
Lee, Po-Tsung
;
光電工程學系
In this report, we propose a square lattice photonic crystal heteroslab-edge microcavity design. In numerical simulations, three surface modes in this microcavity are investigated and optimized by tuning the slab-edge termination tau and gradual mirror layer. High simulated quality (Q) factor of 2.3 x 10(5) and small mode volume of 0.105 mu m(3) are obtained from microcavity with tau = 0.80. In experiments, we obtain and identify different surface modes lasing. The surface mode in the second photonic band gap shows a very-low threshold of 140 mu W and high Q factor of 5,500, which could be an avenue to low-threshold optical lasers and highly sensitive sensor applications with efficient light-matter interactions. c 2010 Optical Society of America
Electrically switchable liquid crystal Fresnel lens using UV-modified alignment film
(2010-12-06)
Jeng, Shie-Chang
;
Hwang, Shug-June
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Horng, Jing-Shyang
;
Lin, Kuo-Ren
;
影像與生醫光電研究所
A simple method to make a switchable liquid crystal (LC) Fresnel lens with high diffraction efficiency and a low driving voltage was proposed based on the photo-induced surface modification of the vertical alignment layer. UV illumination alters the pretilt angle of alignment layers, a Fresnel zone-distribution hybrid alignment in the homeotropic LC cell can be straightforwardly achieved through UV exposure, yielding a concentric structure of the Fresnel phase LC lens. A remarkable diffraction efficiency of similar to 31.4%, close to the measured diffraction efficiency of the used Fresnel-zone-plate mask of 32%, was detected using a linearly polarized incident beam. (C)2010 Optical Society of America
交大e-News第084期
(2010-12-06)
Secretariat
;
國立交通大學秘書室
Pipeline-based reconfigurable mixed-radix FFT processor
(2010-12-07)
Lai
;
Chi-Chen
;
Hwang
;
Wei
The present invention discloses a fast Fourier transform (FFT) processor based on multiple-path delay commutator architecture. A pipelined architecture is used and is divided into 4 stages with 8 parallel data path. Yet, only three physical computation stages are implemented. The process or uses the block floating point method to maintain the signal-to-noise ratio. Internal storage elements are required in the method to hold and switch intermediate data. With good circuit partition, the storage elements can adjust their capacity for different modes, from 16-point to 4096-point FFTs, by turning on or turning off the storage elements.
Light-emitting diode of polymer nanocomposite with quantum dots
(2010-12-07)
Wei
;
Kung-Hwa
;
Chou
;
Chia-Hung
The present invention provides a light-emitting diode made of a polymer nanocomposite doped with quantum dots to improve luminescence efficiency and to increase stability and electrical characteristics.
Interconnect of group III-V semiconductor device and fabrication method for making the same
(2010-12-07)
Lee
;
Cheng-Shih
;
Chang
;
Edward Yi
;
Chang
An interconnect of the group III-V semiconductor device and the fabrication method for making the same are described. The interconnect includes a first adhesion layer, a diffusion barrier layer for preventing the copper from diffusing, a second adhesion layer and a copper wire line. Because a stacked-layer structure of the first adhesion layer/diffusion barrier layer/second adhesion layer is located between the copper wire line and the group III-V semiconductor device, the adhesion between the diffusion barrier layer and other materials is improved. Therefore, the yield of the device is increased.
Highly saturated red-emitting Mn(IV) activated phosphors and method of fabricating the same
(2010-12-07)
Chen
;
Teng-Ming
;
Luo
;
Juih-Tzer
The present invention provides a light emitting device comprising a semiconductor light source emitting radiation at about 250˜500 nm; and a phosphor composition radiationally coupled to the semiconductor light source, wherein the phosphor composition is selected from the group consisting of Mg14(Ge(5-a)Mna)O24, Sr(Ge(4-b)Mnb)O9, Mg2(Ti(1-c)Mnc)O4, Zn2(Ti(1-d)Mnd)O4, SrMg(Al(10-e)Mne)O17, and Y3(Ga(5-f)Mnf)O12.
Multilayered optical bit storage in Sm(DBM)(3)Phen-doped poly(methyl methacrylate) read out by fluorescence and reflection modes
(2010-12-08)
Nie, Z. G.
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Lim, K. S.
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Jang, W. Y.
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Lee, H. Y.
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Lee, M. K.
We report on multilayer optical data storage using Sm(DBM)(3)Phen-doped poly(methyl methacrylate) and a tightly focused 800 nm, 1 kHz, 100 fs pulsed laser. After pulsed femtosecond laser irradiation, refractive-index change and a visible fluorescent bit were formed at the irradiated position inside the bulk sample. The photoluminescence should result from the ligands peeled from the central Sm(3+) ions via bond scission induced by laser irradiation. Multilayer patterns recorded by tightly focusing the pulsed laser beam were read out by a reflection-type fluorescence confocal microscope, which can detect the scattered signal and also the fluorescent signal of the stored bits. The dependence of fluorescence and scattering signals on recording pulse energy was examined. The signal-to-noise ratios via two retrieval modes were compared as a function of recording depth. The detection of the fluorescence signal enables retrieval of the stored bits with a higher S/N ratio.
自《戰爭論》論戰爭
(2010-12-08)
翁明賢
;
開放教育推動中心
;
Open Education Office
課程首頁本課程是由交通大學新文藝復興閱讀計畫提供。 96 年 8 月當各大學紛紛摩拳擦掌準備迎接新生的同時，交通大學校長吳重雨則因為一則來自於七月份泰晤士報，有關於英國首相布朗公布其夏日讀書清單的新聞中，看到了他對知識的尊重。在這同時，吳重雨校長也思考著，要如何為學生準備追求知識的環境和激發他們對知識的尊重與喜愛。台積電張忠謀董事長曾陳述他 18 歲進入哈佛那一年，博覽文史哲理工經典群籍，至此奠定了他求知的基礎，並借海明威名言，將其改為「哈佛這一年為人生可帶走的盛宴。」吳重雨校長以張董事長的學習為借鏡，認為學生固然能藉由自我閱讀的方式學習到豐沛的知識，但透過名人、大師親臨現場地介紹經典書籍，更能加深學子們對於書籍的認識與興趣，這也是「新文藝復興閱讀計劃」 ( 以下簡稱 : 「經典名著選讀」 ) 活動展開籌劃的緣由。於是，吳重雨校長便積極敦請「交大通識教育委員會」，接手籌備本計劃的相關活動，而該中心也成為實際施行本計畫的策動、開課以及認證單位。至此，期許交大學子藉由閱讀、聽講來提昇人文素養、開拓視野的「新文藝復興閱讀計劃」，就此展開。
DRIVING METHOD AND DRIVING DEVICE FOR DRIVING A POLYPHASE INVERTER
(2010-12-09)
HU, Jwu-Sheng
;
CHEN, Keng-Yuan
A driving method for driving a polyphase inverter includes: receiving a reference input that includes a fundamental frequency component, and a previously generated feedback signal; generating an error signal that corresponds to a difference between the reference input and the previously generated feedback signal; attenuating the error signal to the minimum; generating an optimum signal; quantizing the optimum signal; and generating driving signals that correspond to the quantized optimum signal. A driving device that implements the driving method is also disclosed.
SYSTEM AND METHOD FOR MEASURING DISPERSION
(2010-12-09)
JYU, Siao-Shan
;
LAI, Yin-Chieh
;
LIU, Shiou-Fong
;
HSIANG, Wei-Wei
;
CHANG, Hon-Chieh
A method for measuring dispersion in an optical fiber is provided and includes the following steps. A periodic wavelength variation pulse light signal is generated by a periodic frequency-swept pulse light source, in which the periodic wavelength variation pulse light signal has periodic wavelength variations. The periodic wavelength variation pulse light signal is transmitted into a test optical fiber. The periodic wavelength variation pulse light signal propagating through the test optical fiber is detected to generate a sensing signal. The sensing signal is transformed into an RF spectrum to obtain a slow periodic pulse timing variation of the periodic wavelength variation pulse light signal in accordance with the RF spectrum. A dispersion value of the test optical fiber is obtained in accordance with the slow periodic pulse timing variation. A system for measuring dispersion in a fiber is also disclosed herein.
Three-dimensional indium-tin-oxide electrode, method of fabricating the same, device of fabricating the same, and method of fabricating solar cell comprising the same
(2010-12-09)
Chang, Chia-Hua
;
Yu, Pei-Chen
;
Hsu, Min-Hsiang
;
Wei, Kung-Hwa
;
Su, Ming-Shin
A three-dimensional ITO electrode and the method of fabricating the same are disclosed. The three-dimensional ITO electrode of the present invention has a conductive layer and a plurality of ITO nanorods formed on the conductive layer, wherein the length range of the ITO nanorods can vary from 10 nm to 1500 nm. The best length is about 50 nm-200 nm for organic solar cells. When applied into organic optoelectronic devices such as organic solar cells and organic light-emitting diodes (OLEDs), the three-dimensional structure of the ITO electrode may increase the contact area to the active layer, thus improving the electric current collecting efficiency and uniformity of current spreading (flowing). Also, an evaporator, a solar cell comprising the above three-dimensional ITO electrode, and the method of fabricating the solar cell are disclosed.
SENSING PLATFORM
(2010-12-09)
Lin, Chih-Sheng
;
Chuang, Yao-Chen
;
Chen, Sz-Hao
A sensing platform includes: a plurality of metal nanoparticles; a plurality of aggregate inducers each comprising first and second functional groups different from each other, and the first functional group of the aggregate inducers being in contact with the metal nanoparticles; and a plurality of recognition molecules for binding the metal nanoparticles and for interacting with a target to recognize the target, wherein the second functional group of the aggregate inducers is free from being in contact with the metal nanoparticles, and is used to induce the metal nanoparticles to aggregate after the recognition molecules interact with the target.
Controllable oxygen vacancies to enhance resistive switching performance in a ZrO(2)-based RRAM with embedded Mo layer
(2010-12-10)
Wang, Sheng-Yu
;
Lee, Dai-Ying
;
Huang, Tai-Yuen
;
Wu, Jia-Woei
;
Tseng, Tseung-Yuen
In this study, the resistive switching characteristics of a ZrO(2)-based memory film with an embedded Mo layer are investigated. The experimental results show that the forming process can be removed by inserting an embedded Mo metal layer within ZrO(2) via a post-annealing process. The excellent memory performance, which includes lower operation voltage (<1.5 V), good endurance (>10(3) cycles), a stubborn nondestructive readout property (>10(4) s), and long retention time (>10(7) s), is also demonstrated. Moreover, high-speed operation (10 ns) can be successively maintained over 10(3) cycles without any operational errors observed in this memory device. Due to the interface layer induced by the Ti top electrode, the formation and rupture of conducting filaments are suggested to occur near the Ti/ZrO(2) interface. The oxygen vacancies induced by the embedded Mo can enhance the formation of conducting filaments and further improve the switching characteristics in ZrO(2)-based devices.
Synthesis and application of H-Bonded cross-linking polymers containing a conjugated pyridyl H-Acceptor side-chain polymer and various carbazole-based H-Donor dyes bearing symmetrical cyanoacrylic acids for organic solar cells
(2010-12-10)
Sahu, Duryodhan
;
Padhy, Harihara
;
Patra, Dhananjaya
;
Kekuda, Dhananjay
;
Chu, Chih-Wei
A series of novel hydrogen-bonded (H-bonded) cross-linking polymers were generated by complexing various proton-donor (H-donor) solar cell dyes containing 3,6- and 2,7-functionalized electron-donating carbazole cores bearing symmetrical thiophene linkers and cyanoacrylic acid termini with a proton-acceptor (H-acceptor) side-chain homopolymer carrying pyridyl pendants (with 1/2 M ratio of H-donor/H-acceptor). The supramolecular H-bonded structures between H-donor dyes and the H-acceptor side-chain polymer were confirmed by FTIR measurements. The effects of the supramolecular architecture on optical, electrochemical, and organic photovoltaic (OPV) properties were investigated. From DFT (density functional theory) calculations, the optimized geometries of organic dyes reflected that the carbazole cores of H-donor dyes were coplanar with the conjugated thiophenes and cyanoacrylic acids, which is essential for strong conjugations across the donor-acceptor units in D1-D4 dyes. Under 100 mW/cm(2) of AM 1.5 white-light illumination, bulk heterojunction (BHJ) OPV cell devices containing an active layer of H-bonded polymers (PDETP/D1-D4) as an electron donor blended with [6,6]-phenyl C(61)-butyric acid methyl ester (PCBM) as an electron acceptor in a weight ratio of 1:1 were explored. From the preliminary investigations, the OPV device containing 1:1 weight ratio of H-bonded polymer PDFTP/D2 and PCBM showed the best power conversion efficiency (PCE) value of 0.31% with a short-circuit current (J(sc)) of 1.9 mA/cm(2), an open-circuit voltage (V(oc)) of 0.55 V. and a fill factor (FF) of 29%, which has a higher PCE value than the corresponding H-donor D2 dye (PCE = 0.15%) or H-acceptor PDFTP homopolymer (PCE = 0.02%) blended with PCBM in 1:1 weight ratio. (C) 2010 Elsevier Ltd. All rights reserved.