Browsing by Issue Date, starting with "2006-09-11"

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Characterization of O-2-CeO2 interactions using in situ Raman spectroscopy and first-principle calculations
(2006-09-11)
Choi, Y. M.
;
Abernathy, Harry
;
Chen, Hsin-Tsung
;
Lin, M. C.
;
Liu, Meilin
Interactions between O-2 and CeO2 are examined experimentally using in situ Raman spectroscopy and theoretically using density-functional slob-model calculations. Two distinct oxygen bonds appear at 825 and 1131 cm(-1), corresponding to peroxo- and superoxo-like species, respectively, when partially reduced CeO2 is exposed to 10% O-2. Periodic density-functional theory (DFT) calculations aid the interpretation of spectroscopic observations and provide energetic and geometric information for the dioxygen species adsorbed on CeO2. The O-2 adsorption energies on unreduced CeO2 surfaces ore endothermic (0.91 < Delta E-ads < 0.98 eV), while those on reduced surfaces are exothermic (-4. 0 < Delta E-ads < -0.9 eV), depending on other relevant surface processes such as chemisorption and diffusion into the bulk. Partial reduction of surface Ce4+ to Ce3+ (together with formation of oxygen vacancies) alters geometrical parameters and, accordingly, leads to a shift in the vibrational frequencies of adsorbed oxygen species compared to those on unreduced CeO2. Moreover, the location of oxygen vacancies affects the formation and subsequent dissociation of oxygen species on the surfaces. DFT predictions of the energetics support the experimental observation that the reduced surfaces are energetically more favorable than the unreduced surfaces for oxygen adsorption and reduction.
Comparative study of single and multiemissive layers in inverted white organic light-emitting devices
(2006-09-11)
Chu, Ta-Ya
;
Chen, Jenn-Fang
;
Chen, Szu-Yi
;
Chen, Chin H.
;
電子物理學系
The authors have fabricated and compared highly efficient inverted white organic light-emitting devices (WOLEDs) with a single emission layer (SEL) and with a multiemission layer (MEL). The efficiency levels of the WOLEDs with a SEL and a MEL achieved 13.0 cd/A, 10.6 lm/W and 11.3 cd/A, 7.3 lm/W, respectively. The projected half lifetime of a SEL device under an initial luminance of 400 cd/m(2) is expected to be over 34 000 h, which is five times better than that of a MEL device of 6350 h. The Commission International de l'Eclairage coordinates of a SEL device are not affected by aging. (c) 2006 American Institute of Physics.
降低化學氣相沉積銅膜電阻率及提高銅膜Cu（111）／Cu（200）晶向比之電漿處理製程
(2006-09-11)
陳茂傑
;
林成利
;
陳鵬森
本發明關於一種新穎的半導體製程，其特徵在於基板的電漿前置處理及/或後續的銅膜退火處理，利用此項處理步驟可以沉積出具有低電阻率及Cu(111)/Cu(200)高晶向比的化學氣相沉積銅膜，而改善化學氣相沉積銅膜之特性。
可避免鎖住效應之高壓積體電路電源間靜電放電箝制電路
(2006-09-11)
柯明道
;
林昆賢
本發明係揭露一種可避免鎖住效應之高壓積體電路電源間靜電放電箝制電路，其係應用在高壓積體電路上，將由至少二個高壓元件或是由至少一個高壓元件與至少一低壓元件所組成之堆疊元件結構運用在電源間靜電放電箝制電路上，使其在驟轉崩潰之狀態下的保持電壓超過電源供應電壓(VDD)，故可藉此避免高壓積體電路電源間鎖住效應問題的發生。
可提高廢氣處理效率之生物濾料製作法
(2006-09-11)
曾慶平
;
鍾竺均
本發明提供一種生物濾料之製法，該生物濾料係可用提高處理無機與非揮發性有機廢氣之效率，包含以下的步驟：(a)提供一定量之微生物，其中該微生物係對無機或非揮發性有機物廢氣具有分解能力者(含一種或一種以上)；(b)對該微生物進行增殖培養；(c)對增殖培養過的微生物進行離心或濃縮的步驟，以產生一聚集或濃縮微生物；(d)將該聚集或濃縮微生物倒入具有增生能力之培養基容器裡，與一擔體均勻混合，以產生一混合物；以及(e)對該混合物進行固定化的步驟，直到形成具有生物膜的生物濾料。
Blue-light generating femtosecond wavelength-tunable non-collinear optical parametric amplifier
(2006-09-12)
Pan
;
Ci-Ling
;
Huang
;
Jung Y.
;
Zhang
The present invention discloses a means of the generation of tunable femtosecond pulses from 380 nm to 465 nm near the degenerate point of a 405-nm pumped type-I BBO non-collinearly phase-matched optical parametric amplifier (NOPA). The tunable UV/blue radiation is obtained from sum frequency generation (SFG) between the OPA output and the residual fundamental beam at 810-nm and cascaded second harmonic generation (SHG) of OPA. With a pumping energy of 75 mJ at 405 nm, the optical conversion efficiency from the pump to the tunable SFG is more than 5% and the efficiency of SHG of the OPA is about 2%.
松尾芭蕉那隻青蛙
(2006-09-13)
管管
Gain flattened erbium-doped amplifier with 34 nm flat bandwidth
(2006-09-14)
Yeh, C. -H.
;
Lin, M. -C.
;
Chi, S.
;
光電工程學系
;
Department of Photonics
A gain-flattened two-stage erbium-based fibre amplifier module, structured by an erbium-doped waveguide amplifier and an erbium-doped fibre amplifier in serial, is proposed and demonstrated experimentally. In an operating range of 1528 to 1562 nm, all the gain is above 35 d13 and the noise figure is distributed from 5.5 to 6.7 dB, and +/- 1.1 dB maximum gain variation is retrieved at an input saturation power of -25 dBm. As a result, the proposed amplifier not only enhances gain value but possesses flatness in the operating region.
5.7 GHz GalnP/GaAs HBT sub-harmonic gilbert downconverter with octet-phase LO generator
(2006-09-14)
Wu, T. -H.
;
Meng, C.
;
Wu, T. -H.
;
電信工程研究所
;
Institute of Communications Engineering
A 5.7 GHz GaInP/GaAs heterojunction bipolar transistor (HBT) sub-harmonic Gilbert downconversion mixer with octet-phase LO generator is demonstrated. The conversion gain is 15 dB, IP1dB is - 13 dBm, IIP3 is 0 dBm, and IIP2 is 24 dBm when the LO power equals 3 dBm. The measured IF quadrature output waveforms indicate that the phase difference between the in-phase and quadrature-phase output channels is only 1.3 degrees.
Anti-control of chaos of single time-scale brushless DC motor
(2006-09-15)
Ge, Zheng-Ming
;
Chang, Ching-Ming
;
Chen, Yen-Sheng
;
機械工程學系
;
Department of Mechanical Engineering
Anti-control of chaos of single time-scale brushless DC motors is studied in this paper. In order to analyse a variety of periodic and chaotic phenomena, we employ several numerical techniques such as phase portraits, bifurcation diagrams and Lyapunov exponents. Anti-control of chaos can be achieved by adding an external constant term or an external periodic term.
Angular and energy dependences of the surface excitation parameter for electrons crossing a solid surface
(2006-09-15)
Kwei, C. M.
;
Li, Y. C.
;
Tung, C. J.
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
When fast electrons cross a solid surface, surface plasmons may be generated. Surface plasmon excitations induced by electrons moving in the vacuum are generally characterized by the surface excitation parameter. This parameter was calculated for 200-1000 eV electrons crossing the surfaces of An, Cu, Ag, Fe, Si, Ni, Pd, MgO and SiO, with various crossing angles. Such calculations were performed based on the dielectric response theory for both incident (from vacuum to solid) and escaping (from solid to vacuum) electrons. Calculated results showed that the surface excitation parameter increased with crossing angle but decreased with electron energy. This was due to the longer time for electron-surface interaction by glancing incident or escaping electrons and by slow moving electrons. The results were fitted very well to a simple formula, i.e. P-s = aE(-b)/(cosx)(c), where P, is the surface excitation parameter, E is the electron energy, alpha is the angle between the electron trajectory and the surface normal, and a, b and c are material dependent constants. (c) 2006 Elsevier B.V. All rights reserved.
Build-up of supercontinuum in heated and unheated photonic crystal fibers using a chirped femtosecond laser
(2006-09-15)
Lin, Ja-Hon
;
Hsu, Chih-Chang
;
Hsieh, Wen-Feng
;
Lin, Kuel-Huei
;
光電工程學系
The build-up of supercontinuum in a photonic crystal fiber (PCF) has been investigated experimentally as a function of pump power using chirped 100-fs pulses from a Ti:sapphire laser. As compared with the PCF at room temperature, a new blue-shifted spectral component is observed in the initial steps of supercontinuum (SC) generation when the central part of PCF is heated to 120 degrees C by a hot plate. In addition, the slope efficiency of SG is slightly improved with the slightly extension of supercontinuum spectrum in blue edge at high pump powers. The change in dispersion property as well as the effective cascading of nonlinear photonic crystal fibers for heated PCF would be the main attributions. (c) 2006 Elsevier B.V. All rights reserved.
Self-assembled In0.22Ga0.78As quantum dots grown on metamorphic GaAs/Ge/SixGe1-x/Si substrate
(2006-09-15)
Hsieh, Y. C.
;
Chang, E. Y.
;
Luo, G. L.
;
Chen, S. H.
;
Biswas, Dhrubes
Self-assembled In0.22Ga0.78As quantum dots (QDs) grown on Si substrate with Ge/SiGe as buffer layer grown by metal organic vapor phase epitaxy were investigated. Transmission electron microscopy and atomic force microscopy images were used to observe the size and space distribution of the In0.22Ga0.78As QDs grown on the GaAs/Ge/GeSi/Si layer structure. The influence of the growth temperature on the QDs size and density distribution was investigated. For QDs grown at 450 degrees C, the density of the In0.22Ga0.78As dots was estimated to be 1x10(11) cm(-2) and the In0.22Ga0.78As QDs thickness was 5 ML (monolayer) thick. (c) 2006 American Institute of Physics.
X-ray initiated molecular photochemistry of Cl-containing adsorbates on a Si(100) surface using synchrotron radiation
(2006-09-15)
Chen, J. M.
;
Lu, K. T.
;
Lee, J. M.
;
Haw, S. C.
;
電子物理學系
X-ray initiated molecular photochemistry for SiCl(4) and CCl(4) adsorbed on Si(100) at similar to 90 K following C1 2p core-level excitation is investigated by photon stimulated ion desorption and ion kinetic energy distribution measurements. The Cl 2p -> 8a(1)*, excitation of solid SiCl(4) induces the significant enhancement (similar to 900%) of the Cl(+) yield, while the Cl 2p -> 7a(1)* excitation of condensed CCl(4) leads to a moderate enhancement (similar to 500%) of the Cl(+) yield. The enhancement of Cl(+) yield at the specific core-excited states is strongly correlated to the ion escaped energy. Upon X-ray exposure for CCl(4) adsorbed on Si(100) (20-L exposure), the Cl(+) yields at 7a(1)* resonances decrease and new structures at higher photon energies are observed. Cl+ yields at these new resonances are significantly enhanced compared to those at other resonances. These changes are the results of desorption and surface reaction of the CCl(4)-Si surface complex due to X-ray irradiation. We have demonstrated that state-specific enhancement of ion desorption can be successfully applied to characterize the reaction dynamics of adsorbates adsorbed on surfaces by X-ray irradiation. (c) 2006 Elsevier B.V. All rights reserved.
Electroluminescence from a conjugated polymer grafted with CdSe/ZnS: High brightness and improved efficiency
(2006-09-15)
Chen, Kuei-Bai
;
Chen, Ming-Hwey
;
Yang, Sheng-Hsiung
;
Hsieh, Chao-Hsiang
;
Hsu, Chain-Shu
A new series of sulfide-substituted poly(1,4-phenylene vinylene) derivatives (S1PPV-S3PPV) with different composition ratios were successfully synthesized,via the Gilch route. The CdSe/ZnS were grafted to the sulfur atoms by ligand exchange reaction. The grafted CdSe/ZnS contents were determined from TGA analysis to be from 4.6 to 37.8%. A new peak at 1151 cm(-1) formed in FT-IR after ligand exchange, which is attributed to the force formation between sulfur and CdSe. The GPC results show that the molecular weights of final polymers became higher after ligand exchange. Thin films of obtained polymers emitted bright green and yellow light with the max emission peak located from 546 to 556 nm. Double-layer LEDs with an ITO/PEDOT/polymer/Ca/Al configuration were fabricated to evaluate the potential use of these polymers. The turn-on voltages of the devices were about 4-5 V As the CdSe/ZnS content increased in grafted polymers, the device performance was significantly enhanced as compared to pristine polymers. In the case of S3PPV, the double-layer device showed a maximum luminance of 6073 cd/m(2) with a current yield of 0.82 cd/A. The maximum luminance and current yield was enhanced to 13,390 cd/m(2) and 2.25 cd/A by grafting CdSe/ZnS onto polymers. (c) 2006 Wiley Periodicals, Inc.
去除硫化物與資源再生之系統
(2006-09-16)
曾慶平
;
鍾竺均
本發明係為一去除硫化物與資源再生之系統，其藉由化學吸收法將硫化氫氣體吸收與轉化，使轉化之產物於沉澱槽裝置進行分離與回收，並利用生物氧化法將化學吸附劑再生，並將再生後之化學吸附劑迴流至化學除硫槽裝置，繼續與入流之硫化氫氣體進行反應，使系統成為一吸收-氧化-分離-回收-再生之生化密閉循環系統。
音效處理裝置及其處理方法
(2006-09-16)
白明憲
;
白淦元
;
周中權
本發明提出一種音效處理裝置及其處理方法，藉由在一裝置內整合多種特殊音效的處理，並且可以進行雜音效除及斷點消除，使得聲音品質提高，且增進娛樂效果，且因整合於一裝置，可即時播放及操作，可達到較低的運算量。
Evaluating IT/IS investments: A fuzzy multi-criteria decision model approach
(2006-09-16)
Chou, Tzy-Yuan
;
Chou, Seng-cho T.
;
Tzeng, Gwo-Hshiung
;
科技管理研究所
;
Institute of Management of Technology
IT/IS represents a substantial financial investment for many organizations. Whether or not to invest in new IT/IS is, therefore, a difficult decision. Simply considering human resource cost saving criteria is not enough, especially when a corporation has had many information systems. What kind of criteria should we consider when we evaluate IT/IS? How can a new IT/IS project be evaluated in an easy, cost-effective, and collective manner? We need a tool that will help decision-makers evaluate potential new investment projects. Apart from evaluating the new project per se, its compatibility and ability to integrate with an existing IT portfolio must also be considered. Hence, we propose a new approach based on the fuzzy multi-criteria decision model (FMCDM), featuring a 2-stage evaluation process with 26 criteria for IT/IS investment. All stakeholders in a corporation can decide the relative weights they give to the criteria when they evaluate a new IT/IS project by using linguistic values. Experts can also use linguistic values to evaluate all candidates easily. Only an Excel worksheet is needed to obtain an evaluation result. It is cost-effective and efficient. We conduct a case study to show how this model can be used and discuss the results. (c) 2005 Elsevier B.V. All rights reserved.
Emission characteristics of optically pumped GaN-based vertical-cavity surface-emitting lasers
(2006-09-18)
Chu, Jung-Tang
;
Lu, Tien-Chang
;
You, Min
;
Su, Bor-Jye
;
Kao, Chih-Chiang
The laser emission characteristics of a GaN-based vertical-cavity surface-emitting laser with two dielectric distributed Bragg reflectors were investigated under optically pumped operation at room temperature. The laser emitted wavelength at 415.9 nm with an emission linewidth of 0.25 nm and threshold pumping energy of 270 nJ. The laser has a high characteristic temperature of about 278 K and high spontaneous emission coupling factor of 10(-2). The laser emission showed single and multiple spot emission patterns with spectral and spatial variations under different pumping conditions. (c) 2006 American Institute of Physics.
Structure of HfO2 films epitaxially grown on GaAs(001)
(2006-09-18)
Hsu, C. -H.
;
Chang, P.
;
Lee, W. C.
;
Yang, Z. K.
;
Lee, Y. J.
High-quality HfO2 films of technologically important thickness ranging from 1.8 to 17 nm have been grown epitaxially on GaAs (001) by molecular beam epitaxy. Thorough structural and morphological investigations were carried out by x-ray scattering and high-resolution transmission electron microscopy. The films exhibit an atomically sharp interface with the substrate and are of a monoclinic phase with predominant (001)-plane epitaxy between the HfO2 films and GaAs, in spite of a large lattice mismatch of > 8.5%.