Browsing by Issue Date, starting with "2011-04-11"

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Light-driven manipulation of picobubbles on a titanium oxide phthalocyanine-based optoelectronic chip
(2011-04-11)
Yang, Shih-Mo
;
Yu, Tung-Ming
;
Huang, Hang-Ping
;
Ku, Meng-Yen
;
Tseng, Sheng-Yang
Microbubbles have a variety of applications in science and biological technology. Here, we demonstrate the manipulation of the picoliter gas bubble (picobubble) based on the optoelectronic-mechanism. The organic photoconductive material, titanium oxide phthalocyanine (TiOPc), was developed to make the light-sensitive substrate of this optoelectronic chip. The virtual electrodes are formed by projecting the dynamic light pattern onto TiOPc layer for generating the desired nonuniform electric field. The picobubble suspended in silicone oil can be manipulated with the velocity of 40-50 mu m/s. The driving force up to 160 pico-Newtons could be generated for manipulating a gas bubble of 300 picoliters. (C) 2011 American Institute of Physics. [doi:10.1063/1.3580760]
一種利用奈米柱狀結構提升發光二極體光輸出效率之方法
(2011-04-11)
黃泓文
;
盧廷昌
;
邱清華
;
郭浩中
;
王興宗
本發明為一種利用光電化學(PEC)氧化技術形成具有奈米柱狀結構(Nano Rod)之發光二極體技術，首先在發光二極體的表面鍍上一層薄膜金屬層，經熱處理後形成金屬顆粒遮罩，進行蝕刻沒有遮罩保護的部分，再將金屬遮罩移除以形成奈米柱狀結構。接著將形成奈米柱狀結構的發光二極體進行光電化學氧化，即通過一定電壓並照射汞燈，故除正型半導體材料外，材料之表面積均可形成一氧化層，最後再鍍上金屬層，進行導通正型半導體材料以形成具有奈米柱狀結構之發光二極體。
Environment-dependent thermal instability of sol-gel derived amorphous indium-gallium-zinc-oxide thin film transistors
(2011-04-11)
Chung, Wan-Fang
;
Chang, Ting-Chang
;
Li, Hung-Wei
;
Chen, Shih-Ching
;
Chen, Yu-Chun
The environment-dependent electrical performances as a function of temperature for sol-gel derived amorphous indium-gallium-zinc-oxide (a-IGZO) thin film transistors are investigated in this letter. In the ambients without oxygen, thermal activation dominates and enhances device performance. In oxygen-containing environments, mobility and drain current degrades and the threshold slightly increase as temperature increases. We develop a porous model for a-IGZO film relating to the drain current and mobility lowering due to film porosity and oxygen adsorption/penetration. It also relates to the threshold voltage recovery at high temperature owing to the varying form of adsorbed oxygen and the combination of oxygen and vacancies. (C) 2011 American Institute of Physics. [doi:10.1063/1.3580614]
High sensitivity plasmonic index sensor using slablike gold nanoring arrays
(2011-04-11)
Tsai, Chia-Yang
;
Lu, Shao-Ping
;
Lin, Jyun-Wei
;
Lee, Po-Tsung
;
光電工程學系
We investigate the index sensing characteristics of plasmonic arrays based on square lattice slablike gold nanorings (NRs) with different ring widths. The gold NR arrays exhibit two extinction peaks in the visible and near-infrared corresponding to antibonding and bonding modes. Redshift and blueshift in antibonding and bonding modes when broadening the average ring width are observed. We experimentally demonstrate the sensitivity of bonding mode can be tuned by varying the average ring width. High sensitivity of 691 nm per refractive index unit is obtained for NRs with 199 nm average ring width. (C) 2011 American Institute of Physics. [doi:10.1063/1.3579536]
Plasmon-enhanced photoluminescence from bioconjugated gold nanoparticle and nanodiamond assembly
(2011-04-11)
Liu, Y. L.
;
Sun, K. W.
;
應用化學系
;
Department of Applied Chemistry
In this letter, we coupled nanodiamonds (NDs) with gold nanoparticles of different sizes using two complementary DNA sequences. After hybridizing the gold nanoparticles on the NDs, we observed the enhancement of the photoluminescence (PL) signals originating from the nitrogen-vacancy (N-V) center of the ND. The enhancement was attributed to the plasmon field created by the gold nanoparticles. The line shape of the enhanced PL spectra was also affected by the sizes of the attached nanoparticles due to their different resonant plasma frequencies. The signal enhancement can be used as an indexing tool for biosensing applications. (C) 2011 American Institute of Physics. [doi:10.1063/1.3576852]
Dual gate indium-gallium-zinc-oxide thin film transistor with an unisolated floating metal gate for threshold voltage modulation and mobility enhancement
(2011-04-11)
Zan, Hsiao-Wen
;
Chen, Wei-Tsung
;
Yeh, Chung-Cheng
;
Hsueh, Hsiu-Wen
;
Tsai, Chuang-Chuang
In this study, we propose a floating dual gate (FDG) indium-gallium-zinc-oxide (IGZO) thin film transistor (TFT) with a floating metal back gate that is directly contact with IGZO without a dielectric layer. The floating back gate effect is investigated by changing the work function (phi) of the back gate. The FDG IGZO TFT exhibits an improved field-effect mobility (mu), unchanged subthreshold swing (SS), high on/off current ratio, and a tunable threshold voltage ranged (V(th)) from -5.0 to + 7.9 V without an additional back gate power supply. (C) 2011 American Institute of Physics. [doi:10.1063/1.3578403]
Fiber sensing system with self-detection mechanism
(2011-04-12)
Chow
;
Chi-Wai
;
Chi
;
Sien
;
Wang
The present invention discloses a fiber sensing system with self-detection mechanism which utilizes a central office to control secondary ring architecture formed by fiber sensor, remote node and optical coupler primarily. The secondary ring architecture is connected serially to form a primary ring architecture. The central office has a tunable laser light source that can deliver the light source to the fiber sensor. Since the fiber sensor has reflective ability, all light source signal sent by the tunable laser light source will be detected and measured by the fiber sensor. Thus central office can detect all signals reflected by the fiber sensor and produce a spectrum for analyzing fault point locations. The present invention can greatly enhance survivability and sensing capacity of all fiber sensors, so that when a fault point caused by environmental change within the fiber, it will not effect the overall operation of the sensing mechanism. The application of fiber sensor can also reduce cost and complexity of the overall fiber network topology.
Crystal-less communications device and self-calibrated clock generation method
(2011-04-12)
Lee
;
Chen-Yi
;
Yu
;
Jui-Yuan
A communication device uses a local clock generator to regenerate the carrier frequency of the reference signal from a remote communication. In particular, a closed loop is used to self-calibrate the local pulse till the frequency is fixed to be within a fixed frequency margin. Once the local pulse is obtained, the demodulator will use the local pulse to demodulate the reference signal to generate the data signal.
Highly graphitized laterally interconnected SWCNT network synthesis via a sandwich-grown method
(2011-04-13)
Teng, I-Ju
;
Chen, Kai-Ling
;
Hsu, Hui-Lin
;
Jian, Sheng-Rui
;
Wang, Li-Chun
We present a sandwich-grown method for growing laterally interconnected single-walled carbon nanotube (SWCNT) networks with a high degree of graphitization by microwave plasma chemical vapour deposition (MPCVD). An Al(2)O(3)-supported Fe catalyst precursor layer deposited on an oxidized Si substrate with an upper Si cover is first pretreated in pure hydrogen, and then exposed to a gas mixture of methane/hydrogen for growth process at a lower growth temperature and a faster rate. The effects of various parameters, such as catalyst film thickness, gas flow rate, working pressure, growth time and plasma power, on the morphologies and structural characteristics of the SWCNT networks are investigated, and therefore provide the essential conditions for direct growth of laterally interconnected SWCNT networks. Analytical results demonstrate that the SWCNT-based lateral architecture comprises a mixture of graphene-sheet-wrapped catalyst particles and laterally interconnected nanotubes, isolated or branched or assembled into bundles. The results also show that the formation of the laterally interconnected SWCNT networks is related to the sandwich-like stack approach and the addition of an Al(2)O(3) layer in the MPCVD process. The successful growth of lateral SWCNT networks provides new experimental information for simply and efficiently preparing lateral SWCNTs on unpatterned substrates, and opens a pathway to create network-structured nanotube-based devices.
軍醫．學者．文豪森鷗外（1862-1922）－其人及文學
(2011-04-13)
邱若山
;
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。
Process for treating nitrogenous wastewater with simultaneous autotrophic denitrification, hetertrophic denitrification and COD removal
(2011-04-14)
Lee, Der-Ming
;
Chiang, Ming-Kuei
;
Chen, Chin-Te
;
Sung, Keng-Chuan
;
Lin, Jih-Gaw
A process for treating nitrogenous wastewater contains an autotrophic denitrification reaction, a heterotrophic denitrification reaction and a COD removal reaction simultaneously and mixedly taking place in a single reactor. The nitrification reaction is caused by nitrifying bacteria, in which ammonium is oxidized into nitrite. The autotrophic denitrification reaction is caused by autotrophic denitrifying bacteria, in which ammonium used as electron donor and nitrite used as electron acceptor are converted into nitrogen gas and nitrate. The heterotrophic denitrification reaction is caused by heterotrophic denitrifying bacteria, in which nitrate and COD are consumed. It is not necessary to build two separate reactors for aerobic nitrification and anaerobic denitrification, thereby effectively reducing the fabrication and operation cost.
Uniplanar microstrip periodic structure for microwave circuits
(2011-04-14)
Chang, W. S.
;
Chang, C. Y.
;
電信工程研究所
;
Institute of Communications Engineering
A novel microstrip slow-wave structure is presented. The slow-wave factor is mainly controlled by the signal strip and the inserted ground metal pattern in a coplanar manner. A third-order Chebyshev filter was designed and fabricated to demonstrate the proposed structure. Good agreement between the simulated and measured responses is observed.
Document Processing System and Method Thereof
(2011-04-14)
LEE, CHIA-HOANG
;
LIAO, ZAN-WEI
In a document processing system and a document processing method, the document processing method includes the steps of: obtaining a document and dividing the document into a plurality of terms and giving a syntactic index to each of the terms; dividing the document into a plurality of sentences; selecting a key syntactic index from the syntactic indexes, and transforming each of the sentences into a preliminary key terms sequence which includes a preliminary key term corresponding to the key syntactic indexes according to the key syntactic indexes; selectively expanding the preliminary key term of a representative sentence of the document into an advanced key term; and determining at least one core candidate sentence among the sentences to generate a core abstract of the document according to the preliminary key terms and the advanced key term.
Infrared absorption of methanol clusters (CH(3)OH)(n) with n=2-6 recorded with a time-of-flight mass spectrometer using infrared depletion and vacuum-ultraviolet ionization
(2011-04-14)
Han, Hui-Ling
;
Camacho, Cristopher
;
Witek, Henryk A.
;
Lee, Yuan-Pern
;
應用化學系
We investigated IR spectra in the CH-and OH-stretching regions of size-selected methanol clusters, (CH(3)OH)(n) with n = 2-6, in a pulsed supersonic jet by using the IR-VUV (vacuum-ultraviolet) ionization technique. VUV emission at 118 nm served as the source of ionization in a time-of-flight mass spectrometer. The tunable IR laser emission served as a source of predissociation or excitation before ionization. The variations of intensity of protonated methanol cluster ions (CH(3)OH)(n)H(+) and CH(3)OH(+) and (CH(3)OH)(2)(+) were monitored as the IR laser light was tuned across the range 2650-3750 cm(-1). Careful processing of these action spectra based on photoionization efficiencies and the production and loss of each cluster due to photodissociation yielded IR spectra of the size-selected clusters. Spectra of methanol clusters in the OH region have been extensively investigated; our results are consistent with previous reports, except that the band near 3675 cm(-1) is identified as being associated with the proton acceptor of (CH(3)OH)(2). Spectra in the CH region are new. In the region 2800-3050 cm(-1), bands near 2845, 2956, and 3007 cm(-1) for CH(3)OH split into 2823, 2849, 2934, 2955, 2984, and 3006 cm(-1) for (CH(3)OH)(2) that correspond to proton donor and proton acceptor, indicating that the methanol dimer has a preferred open-chain structure. In contrast, for (CH(3)OH)(3), the splitting diminishes and the bands near 2837, 2954, and 2987 cm(-1) become narrower, indicating a preferred cyclic structure. Anharmonic vibrational wavenumbers predicted for the methanol open-chain dimer and the cyclic trimer with the B3LYP/VPT2/ANO1 level of theory are consistent with experimental results. For the tetramer and pentamer, the spectral pattern similar to that of the trimer but with greater widths was observed, indicating that the most stable structures are also cyclic. (C) 2011 American Institute of Physics. [doi:10.1063/1.3572225]
He I Ultraviolet Photoelectron Spectroscopy of Benzene and Pyridine in Supersonic Molecular Beams Using Photoelectron Imaging
(2011-04-14)
Liu, Suet-Yi
;
Alnama, Koutayba
;
Matsumoto, Jun
;
Nishizawa, Kiyoshi
;
Kohguchi, Hiroshi
We performed He I ultraviolet photoelectron spectroscopy (UPS) of jet-cooled aromatic molecules using a newly developed photoelectron imaging (PEI) spectrometer. The PEI spectrometer can measure photoelectron spectra and photoelectron angular distributions at a considerably higher efficiency than a conventional spectrometer that uses a hemispherical energy analyzer. One technical problem with PEI is its relatively high susceptibility to background electrons generated by scattered He I radiation. To reduce this problem, we designed a new electrostatic lens that intercepts background photoelectrons emitted from the repeller plate toward the imaging detector. An energy resolution (Delta E/E) of 0.735% at E = 5.461 eV is demonstrated with He I radiation. The energy resolution is limited by the size of the ionization region. Trajectory calculations indicate that the system is capable of achieving an energy resolution of 0.04% with a laser if the imaging resolution is not limited. Experimental results are presented for jet-cooled benzene and pyridine, and they are compared with results in the literature.
Infrared absorption of methanol clusters (CH3OH)(n) with n=2-6 recorded with a time-of-flight mass spectrometer using infrared depletion and vacuum-ultraviolet ionization
(2011-04-14)
Han, Hui-Ling
;
Camacho, Cristopher
;
Witek, Henryk A.
;
Lee, Yuan-Pern
;
應用化學系
We investigated IR spectra in the CH-and OH-stretching regions of size-selected methanol clusters, (CH3OH)(n) with n = 2-6, in a pulsed supersonic jet by using the IR-VUV (vacuum-ultraviolet) ionization technique. VUV emission at 118 nm served as the source of ionization in a time-of-flight mass spectrometer. The tunable IR laser emission served as a source of predissociation or excitation before ionization. The variations of intensity of protonated methanol cluster ions (CH3OH)(n)H+ and CH3OH+ and (CH3OH)(2)(+) were monitored as the IR laser light was tuned across the range 2650-3750 cm(-1). Careful processing of these action spectra based on photoionization efficiencies and the production and loss of each cluster due to photodissociation yielded IR spectra of the size-selected clusters. Spectra of methanol clusters in the OH region have been extensively investigated; our results are consistent with previous reports, except that the band near 3675 cm(-1) is identified as being associated with the proton acceptor of (CH3OH)(2). Spectra in the CH region are new. In the region 2800-3050 cm(-1), bands near 2845, 2956, and 3007 cm(-1) for CH3OH split into 2823, 2849, 2934, 2955, 2984, and 3006 cm(-1) for (CH3OH)(2) that correspond to proton donor and proton acceptor, indicating that the methanol dimer has a preferred open-chain structure. In contrast, for (CH3OH)(3), the splitting diminishes and the bands near 2837, 2954, and 2987 cm(-1) become narrower, indicating a preferred cyclic structure. Anharmonic vibrational wavenumbers predicted for the methanol open-chain dimer and the cyclic trimer with the B3LYP/VPT2/ANO1 level of theory are consistent with experimental results. For the tetramer and pentamer, the spectral pattern similar to that of the trimer but with greater widths was observed, indicating that the most stable structures are also cyclic. (C) 2011 American Institute of Physics. [doi:10.1063/1.3572225]
Synthesis, Characterization and Photophysical Properties of DCM-Based Light-Harvesting Dendrimers
(2011-04-15)
Vanjinathan, Mahalingam
;
Lin, Hong-Cheu
;
Nasar, A. Sultan
;
材料科學與工程學系
;
Department of Materials Science and Engineering
A series of highly soluble light-harvesting dendrimers up to third generation were synthesized using a DCM-based core and Frechet-type benzyl ether dendrons containing pyrene end groups. All dendrimers and intermediates were characterized by FTIR, (1)H NMR, MALDI-TOF MS, UV-Vis, and PL spectra and EA, GPC, and TGA techniques. The dendrimers emit strong red PL around 570 nm. The excitation of the terminal chromophores results in core emission alone, as the donor emission is seriously quenched due to FRET to the core. The dendrimers showed enhanced luminescence properties of the core, and its efficiency was dependent on the generation number of the dendrimers. The above results reveal that these dendrimers are suitable candidates for red emissive materials in OLEDs.
Alternating Copolymers Incorporating Cyclopenta[2,1-b:3,4-b ']dithiophene Unit and Organic Dyes for Photovoltaic Applications
(2011-04-15)
Cheng, Yen-Ju
;
Hung, Lung-Chang
;
Cao, Fong-Yi
;
Kao, Wei-Shun
;
Chang, Chih-Yu
We have synthesized six p-type copolymers, CPDT-co-TPADCN, CPDT-co-TPADTA, CPDT-co-TPATCN, CPDT-coDFADCN, CPDT-co-DFADTA, and CPDT-co-DFATCN, consisting of a cyclopenta[2,1-b:3,4-b']dithiophene (CPDT) unit and an organic dye in an alternating arrangement. Triphenylamine (TPA) or difluorenylphenyl amine (DFA) units serve as the electron donors, whereas dicyanovinyl (DCN), 1,3-diethyl-2-thiobarbituric acid, or tricyanovinyl (TCN) units act as the electron acceptors in the dyes. The target polymers were prepared via Stille coupling, followed by postfunctionalization to introduce the electron acceptors to the side chains. Because of the strongest withdrawing ability of TCN acceptor to induce efficient intramolecular charge transfer, CPDT-co-TPATCN and CPDT-co-DFATCN exhibit the broader absorption spectra covering from 400 to 900 nm and the narrower optical band gaps of 1.34 eV. However, the CPDT-co-TPATCN:PC(71)BM and CPDT-co-DFATCN:PC(71)BM based solar cells showed the power conversion efficiencies (PCEs) of 0.22 and 0.31%, respectively, due to the inefficient exciton dissociation. The DFA-based polymers possess deeper-lying HOMO energy levels than the TPA-based polymer analogues, leading to the higher V(oc) values and better efficiencies. The device based on CPDT-co-DFADTA:PC(71)BM blend achieved the best PCE of 1.38% with a V(oc) of 0.7 V, a J(sc) of 4.57 mA/cm(2), and a fill factor of 0.43. (C) 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 49:1791-1801, 2011
Electrode dependence of filament formation in HfO2 resistive-switching memory
(2011-04-15)
Lin, Kuan-Liang
;
Hou, Tuo-Hung
;
Shieh, Jiann
;
Lin, Jun-Hung
;
Chou, Cheng-Tung
This study investigates bipolar and nonpolar resistive-switching of HfO2 with various metal electrodes. Supported by convincing physical and electrical evidence, it is our contention that the composition of conducting filaments in HfO2 strongly depends upon the metal electrodes. Nonpolar resistive-switching with the Ni electrode is attributed to the migration of metal cations and the corresponding electrochemical metallization. Conversely, oxygen-deficient filaments induced by anion migration are responsible for bipolar resistive-switching. It was also found that the characteristic nature of the conducting filaments influences many aspects of switching characteristics, including the switching power, cycling variations, and retention at elevated temperatures. (C) 2011 American Institute of Physics. [doi:10.1063/1.3567915]
Electrode dependence of filament formation in HfO(2) resistive-switching memory
(2011-04-15)
Lin, Kuan-Liang
;
Hou, Tuo-Hung
;
Shieh, Jiann
;
Lin, Jun-Hung
;
Chou, Cheng-Tung
This study investigates bipolar and nonpolar resistive-switching of HfO(2) with various metal electrodes. Supported by convincing physical and electrical evidence, it is our contention that the composition of conducting filaments in HfO(2) strongly depends upon the metal electrodes. Nonpolar resistive-switching with the Ni electrode is attributed to the migration of metal cations and the corresponding electrochemical metallization. Conversely, oxygen-deficient filaments induced by anion migration are responsible for bipolar resistive-switching. It was also found that the characteristic nature of the conducting filaments influences many aspects of switching characteristics, including the switching power, cycling variations, and retention at elevated temperatures. (C) 2011 American Institute of Physics. [doi:10.1063/1.3567915]