Browsing by Issue Date, starting with "2013-01-14"

Now showing 1 - 20 of 32677

Exploration of water jet generated by Q-switched laser induced water breakdown with different depths beneath a flat free surface
(2013-01-14)
Chen, Ross C. C.
;
Yu, Y. T.
;
Su, K. W.
;
Chen, J. F.
;
Chen, Y. F.
The dynamics of a water jet on a flat free surface are investigated using a nanosecond pulsed laser for creating an oscillating bubble with different depths beneath the free surface. A thin jet is shown to deform a crater surface resulted from surface depression and cause a circular ring-shaped crater on the connection surface between the crater of surface depression and the thin jet. The collapse of this circular ring-shaped crater is proposed to the crown-like formation around a thick jet. The evolution of the bubble depth suggests a classification of four distinctive ranges of the bubble depths: non-crown formation when the parameter of bubble depth over the maximum bubble radius gamma <= 0.5, unstable crown formation when 0.5 <= gamma <= 0.6, crown-like structure with a complete crown wall when 0.6 <= gamma <= 1.1, and non-crown formation when 1.1 <= gamma. Furthermore, the orientation of the crown wall gradually turns counterclockwise to vertical direction with increasing gamma from 0.5 to 1.1, implying a high correlation between the orientation of the crown wall and the depth of the bubble. This correlation is explained and discussed by the directional change of the jet eruption from the collapse of circular ring-shaped crater. (C)2013 Optical Society of America
SSII cancellation in an EAM-based OFDM-IMDD transmission system employing a novel dynamic chirp model
(2013-01-14)
Hsu, Dar-Zu
;
Wei, Chia-Chien
;
Chen, Hsing-Yu
;
Lu, Yi-Cheng
;
Song, Cih-Yuan
We develop a novel subcarrier-to-subcarrier intermixing interference (SSII) cancellation technique to estimate and eliminate SSII. For the first time, the SSII cancellation technique is experimentally demonstrated in an electro-absorption modulator-(EAM-) based intensity-modulation-direct-detection (IMDD) multi-band OFDM transmission system. Since the characteristics of SSII are seriously affected by the chirp parameter, a simple constant chirp model, we found, cannot effectively remove the SSII. Therefore, assuming that the chirp parameter linearly depends on the optical power, a novel dynamic chirp model is developed to obtain better estimation and cancellation of SSII. Compared with 23.6% SSII cancellation by the constant chirp model, our experimental results show that incorporating the dynamic chirp model into the SSII cancellation technique can achieve up to 74.4% SSII cancellation and 2.8-dB sensitivity improvement in a 32.25-Gbps OFDM system over 100-km uncompensated standard single-mode fiber. (C) 2013 Optical Society of America
An optimized surface plasmon photovoltaic structure using energy transfer between discrete nano-particles
(2013-01-14)
Lin, Albert
;
Fu, Sze-Ming
;
Chung, Yen-Kai
;
Lai, Shih-yun
;
Tseng, Chi-Wei
Surface plasmon enhancement has been proposed as a way to achieve higher absorption for thin-film photovoltaics, where surface plasmon polariton(SPP) and localized surface plasmon (LSP) are shown to provide dense near field and far field light scattering. Here it is shown that controlled far-field light scattering can be achieved using successive coupling between surface plasmonic (SP) nano-particles. Through genetic algorithm (GA) optimization, energy transfer between discrete nano-particles (ETDNP) is identified, which enhances solar cell efficiency. The optimized energy transfer structure acts like lumped-element transmission line and can properly alter the direction of photon flow. Increased in-plane component of wavevector is thus achieved and photon path length is extended. In addition, Wood-Rayleigh anomaly, at which transmission minimum occurs, is avoided through GA optimization. Optimized energy transfer structure provides 46.95% improvement over baseline planar cell. It achieves larger angular scattering capability compared to conventional surface plasmon polariton back reflector structure and index-guided structure due to SP energy transfer through mode coupling. Via SP mediated energy transfer, an alternative way to control the light flow inside thin- film is proposed, which can be more efficient than conventional index-guided mode using total internal reflection (TIR). (C)2012 Optical Society of America
Optical coupling from InGaAs subcell to InGaP subcell in InGaP/InGaAs/Ge multi-junction solar cells
(2013-01-14)
Shu, G. W.
;
Lin, J. Y.
;
Jian, H. T.
;
Shen, J. L.
;
Wang, S. C.
Spatially-resolved electroluminescence (EL) images in the triple junction InGaP/InGaAs/Ge solar cell have been investigated to demonstrate the subcell coupling effect. Upon irradiating the infrared light with an energy below bandgap of the active layer in the top subcell, but above that in the middle subcell, the EL of the top subcell quenches. By analysis of EL intensity as a function of irradiation level, it is found that the coupled p-n junction structure and the photovoltaic effect are responsible for the observed EL quenching. With optical coupling and photoswitching effects in the multi-junction diode, a concept of infrared image sensors is proposed. (C)2012 Optical Society of America
Influence of forming process on resistance switching characteristics of In2O3/SiO2 bi-layer
(2013-01-15)
Huang, Jheng-Jie
;
Chang, Ting-Chang
;
Yang, Po-Chun
;
Chen, Yu-Ting
;
Tseng, Hsueh-Chih
In this study, we fabricated and analyzed resistance switching characteristics for resistance random access memory (RRAM) in a Pt/In2O3/SiO2/TiN structure. By applying opposing electric fields to performa soft breakdown of the In2O3/SiO2 insulating bi-layer, different switching behaviors are exhibited. When positive forming voltage was applied to the TiN electrode to soft breakdown the device, the resistance switching behavior was dominated by the bipolar mode. However, the negative voltage forming process exhibited both unipolar switching characteristics in addition to a bipolar switch mode. In order to analyze the composition of the conduction path and resistance switching mechanism, resistance value trends versus temperature was extracted and showed that the conduction paths of bipolar and unipolar modes are dominated by oxygen vacancies and metallic filament, respectively. Hence, metallic filament was considered to be formed by the migration of indium ions because the unipolar characteristic was only present during negative bias forming condition. (c) 2012 Elsevier B.V. All rights reserved.
Effect of thermal treatment on physical, electrical properties and reliability of porogen-containing and porogen-free ultralow-k dielectrics
(2013-01-15)
Chang, Yu-Min
;
Chang, Wei-Yuan
;
Huang, Jun-Fu
;
Leu, Jihperng
;
Cheng, Yi-Lung
The effects of thermal annealing on the physical, electrical properties and reliability of porogen-containing and porogen-free ultralow-k dielectrics prepared by plasma-enhanced chemical vapor deposition (PECVD) are investigated. The porogen-free low-k dielectrics are obtained by using UV curing process to removal organic sacrificial phase and to generate open porosity. The results are compared with PECVD porogen-containing low-k films fabricated without UV curing process and PECVD low-k dielectrics deposited without organic sacrificial phase. The experimental results show that all low-k films remained stable after they were experimentally heating to temperatures up to 700 degrees C. The non-porous low-k films also showed the highest reliability. Although the porous-free low-k film requires an additional UV curing process, the heat stress confirmed that its thermal stability was better than that of the porogen-containing low-k film. At an annealing temperature above 500 degrees C, the heating process is comparable to UV curing, but does not provide Si-O-Si cross-linking within the film. At an annealing of 600 degrees C, the porogen-free low-k films have a relatively higher breakdown electric-field and longer failure time in comparison to the porogen-containing low-k films. However, pores generated in porogen-containing low-k films at high temperature cause reliability to degrade with annealing temperature. Crown Copyright (c) 2012 Published by Elsevier B.V. All rights reserved.
Morphology evolution of a-plane ZnO films on r-plane sapphire with growth by pulsed laser deposition
(2013-01-15)
Peng, Chun-Yen
;
Tian, Jr-Sheng
;
Wang, Wei-Lin
;
Ho, Yen-Teng
;
Chang, Li
In this study, the morphology evolution of epitaxial a-plane ZnO on r-plane sapphire at low and high temperatures with growth by pulsed laser deposition (PLD) are presented. Examination of the surfaces of ZnO films during growth was done with in situ reflection high energy electron diffraction, and atomic force microscopy was used to examine the surface morphology of the corresponding films after growth. For initial growth, it was observed that (1 x 2) reconstruction on ZnO grown at 750 degrees C (HT-ZnO) occurred with step-flow growth, while ZnO grown at 450 degrees C (LT-ZnO) exhibited island growth mode. For thick films both HT- and LT-ZnO surfaces eventually develop into stripe morphology. Significant change of surface morphology during cooling had also been observed. (C) 2012 Elsevier B.V. All rights reserved.
Enhanced cooling for LED lighting using ionic wind
(2013-01-15)
Chen, Ing Youn
;
Guo, Mei-Zuo
;
Yang, Kai-Shing
;
Wang, Chi-Chuan
;
機械工程學系
This study employs ionic wind to augment heat transfer of a LED mounted on a substrate. The size of the LED chip is 0.9 mm x 0.9 mm with a nominal power of 1 W. A needle type electrode is used to generate ionic wind with the applied voltage ranging from 4 to 11 kV. The effects of aligned angle, electrode polarity, separation distance, and ground configuration on the thermal resistance of the LED substrate are examined in this study. For the same applied voltage, it appears that the thermal resistance for the negative polarity is lower than that for the positive one and the negative electrode also has a wilder operation range. The thermal resistance can be reduced as much as 50% in the test range. The thermal resistance is slightly reduced when the aligned angle is increased from 0 degrees to 20 degrees, but a further increase of aligned angle casts no further reduction on the thermal resistance. It is found that the influence of vertical separation distance between the needle and ground electrode is moderately higher than that of horizontal separation distance. Test results also indicate that the mesh ground electrode shows moderately lower thermal resistance than those of point or line electrode. (C) 2012 Elsevier Ltd. All rights reserved.
Structure and property of epitaxial titanium oxynitride grown on MgO(001) substrate by pulsed laser deposition
(2013-01-15)
Do, Hien
;
Wu, Yue-Han
;
Van-Truong Dai
;
Peng, Chun-Yen
;
Yen, Tzu-Chun
High-quality epitaxial TiNxOy, films with different oxygen content were deposited on MgO(001) substrates by pulsed laser deposition method. The chemical composition of the deposited films was determined by X-ray photoelectron spectroscopy. X-ray diffraction results showed that the TiNxOy films are heteroepitaxially grown on MgO with good crystallinity and their lattice parameters decrease with increased oxygen concentration. Transmission electron microscopy analyses showed that TiNxOy films contain a low density of dislocations. Atomic force microscopy revealed very smooth surfaces of TiNxOy films with roughness of 026-0.29 nm. The resistivity of TiNxOy, films determined by Hall measurement was about 28-33 mu Omega cm. Nanoindentation measurements showed the film hardness and Young's modulus of about 23-26 GPa and 400-430 GPa, respectively. (C) 2012 Elsevier B.V. All rights reserved.
The resistive switching characteristics in TaON films for nonvolatile memory applications
(2013-01-15)
Chen, Min-Chen
;
Chang, Ting-Chang
;
Chiu, Yi-Chieh
;
Chen, Shih-Cheng
;
Huang, Sheng-Yao
In this study, the bipolar resistive switching characteristics of the resistive random access memory (RRAM) device based on sputter-deposited TaON thin film were investigated. The proposed memory device exhibits excellent resistance switching behavior with a high resistance state to low resistance state ratio of 2.5 order, write/erase endurance of about 1.5 order, and long retention time of 10(4) s at 85 degrees C. In addition, the device was investigated to achieve multilevel operation, which could increase storage density for next generation memory application. It was also found that the polarity of the forming process would not influence the resistive switching characteristic but would affect the first reset process behavior. The switching behavior could be regarded as the oxygen redox near the TiN interface. However, the first reset behavior of negative forming process was related to the oxygen concentration gradients near the Pt electrode and the Joule heating enhanced oxidation. (c) 2012 Elsevier B.V. All rights reserved.
How tantalum proceeds phase change on tantalum nitride underlayer with sequential Ar plasma treatment
(2013-01-15)
Tsao, Jung-Chih
;
Liu, Chuan-Pu
;
Fang, Hsin-Chiao
;
Wang, Ying-Lang
;
光電學院
Tantalum can change its phase from high resistive beta-Ta to low resistive alpha-Ta phase on a TaN substrate with sequential Ar plasma treatment on the TaN layer surface prior to Ta deposition. The underlined mechanism of phase evolution is proposed based on systematic microstructure examination by high-resolution transmission electron microscopy. The images show that, with argon treatment, the upper part of the TaN film is transformed from amorphous-TaN to a composite phase of bcc-Ta(N) and amorphous-TaN mixture, which is also confirmed by X-ray diffraction patterns. The composite film composed of less nitrogen provides an ideal cubic matrix to confine the stable alpha-Ta phase to be grown. The alpha-Ta/bcc-Ta(N) film obtained by proper argon treatment results in film resistivity 10 times lower than the traditional Ta/TaN film. (C) 2012 Elsevier B.V. All rights reserved.
Impact of strain on gate-induced floating body effect for partially depleted silicon-on-insulator p-type metal-oxide-semiconductor-field-effect-transistors
(2013-01-15)
Lo, Wen-Hung
;
Chang, Ting-Chang
;
Dai, Chih-Hao
;
Chung, Wan-Lin
;
Chen, Ching-En
This work investigates impact of mechanical strain on gate-induced-floating-body-effect (GIFBE) for partially depleted silicon-on-insulator p-type metal-oxide-semiconductor field effect transistors (PD SOI p-MOSFETs). First part, the original mechanism of GIFBE on PD SOI p-MOSFETs is studied. The experimental results indicate that GIFBE causes a reduction in oxide electric field (E-ox), resulting in an underestimate of negative-bias temperature instability (NBTI) degradation. This can be attributed to the electrons tunneling from the process-induced partial n(+) poly gate and anode electron injection (AEI) model, rather than the electron valence band tunneling (EVB) widely accepted as the mechanism for n-MOSFETs. And then, the second part shows that the strained FB device has less NBTI degradation than the unstrained devices. This behavior can be attributed to the fact that more electron accumulation was induced by strain-induced band gap narrowing, reducing NBTI significantly. (c) 2012 Elsevier B.V. All rights reserved.
Ligand and metal complex
(2013-01-15)
Wang Yun-Ming
;
Chen Ting-Jung
A ligand of Formula (I) is provided: wherein A4 represents a hydrogen atom, a nitro group, an amino group, a thiocyanato group, or —Z—Y, in which Z is a divalent linking group and Y is a group derived from a biocompatible molecule, with the proviso that when X is methylene, A4 cannot be a hydrogen atom or a nitro group. A metal complex having the ligand is also provided and is useful as a blood pool contrast agent or a targeting contrast agent.
一種電子顯微鏡樣品盒
(2013-01-16)
陳智
;
杜經寧
本發明係有關於一種電子顯微鏡樣品盒，包括：一第一基板、一第二基板、一或以上之光電元件、及一金屬黏著層。該第一基板具有一第一表面、一第二表面、一第一凹槽、及一或以上之第一導孔，該第一導孔係貫穿第一基板。該第二基板具有一第三表面、一第四表面、及一第二凹槽。該光電元件係設置於第一基板及第二基板間。另外，該金屬黏著層，係設置於該第一基板與該第二基板間以形成一空間，使樣品容置於其中。此外，本發明更包括一或以上之栓塞，係可密封第一導孔，使本發明之樣品盒密封並以電子顯微鏡即時觀測。
具磁控制之奈米孔洞型藥物載體
(2013-01-16)
陳三元
;
陳柏溶
;
劉典謨
;
胡尚秀
本發明提供一種具磁控制之奈米孔洞型藥物載體，其利用一無機或有機之基材來裝載藥物，作為藥物載體，並使用具有磁敏感性的磁性奈米粒子包覆於基材表面，以將藥物封圍起來。本發明之具磁控制之奈米孔洞型藥物載體可利用一外部磁場訊號來控制磁性奈米粒子的移除率，以控制藥物釋放行為及釋放量。
一種電子顯微鏡樣品盒
(2013-01-16)
陳智
;
杜經寧
本發明係有關於一種電子顯微鏡樣品盒，包括：一第一基板、一第二基板、及一金屬黏著層。該第一基板具有一第一表面、一第二表面、一第一凹槽、及一或以上之第一導孔，該第一導孔係貫穿第一基板。該第二基板具有一第三表面、一第四表面、及一第二凹槽。另外，該金屬黏著層，係設置於該第一基板與該第二基板間以形成一空間，使樣品容置於其中，此外，本發明更包括一或以上之栓塞，係可密封第一導孔，使本發明之樣品盒密封並以電子顯微鏡即時觀測。
載藥型隱形眼鏡及其製備方法
(2013-01-16)
劉典謨
;
劉佩鈴
本發明係揭露一種載藥型隱形眼鏡及其製備方法，此載藥型隱形眼鏡具有一隱形眼鏡本體，隱形眼鏡本體至少包含有一雙性混成奈米載體，其上係載有藥物分子。本發明更藉由藥物分子之光或熱敏感性差異，以分別製作出兩種不同類型的包覆型及浸藥型之載藥型隱形眼鏡。本發明係利用具有良好藥物包覆能力和生物相容性極高之雙性混成奈米載體包覆藥物分子，達到藥物分子長期緩慢釋放至眼睛組織裡，使藥物之損失、對人體產生副作用機率降至最低，以達到醫療、保健目的者。
可消除雜音且增進語音辨識率之方法
(2013-01-16)
白明憲
;
劉孆婷
;
桂振益
;
徐偉智
一種可消除雜音且增進語音辨識率之方法，包括以下步驟：提供二個以上的麥克風，用以接收至少二麥克風訊號；將麥克風訊號利用快速傅立葉轉換至頻率域，以取得其中之語音訊號與雜音訊號；計算語音訊號與雜音訊號之夾角，並使用一相位差演算法，進一步找出一耳間時間差；依據該夾角計算出耳間時間差之一閥值；依據耳間時間差與其閥值，使用一遮蔽法則，以取得語音訊號並去除雜音訊號；以及將語音訊號利用一反快速傅立葉轉換暨疊加模組轉至時間域輸出，藉此去除聲源中的雜音部分，以增進語音品質。
基於擴增實境與雲端計算之應用程式執行方法與系統
(2013-01-16)
陳烈武
;
曾煜棋
;
彭昱豪
一種創新的應用程式執行方法與系統，可利用動態影像或靜態照片來讓使用者取得欲通訊/查詢對象之識別帳號並觸發特定程式/網頁功能的人性化介面。本發明讓使用者不必自行輸入欲通訊對象的識別帳號，如E-Mail位址、MSN識別、Facebook識別、FTP IP、甚至是關鍵字等，只需一指拖曳人臉到應用程式圖示/網頁圖示上或將該應用程式圖示/網頁圖示拖曳到該人臉上，即可輕鬆完成執行應用程式/網站功能的過程，有效地降低使用者操作複雜度，並提供簡易的應用軟體與網站服務操作方法。
光感測元件及其製備方法
(2013-01-16)
陳智
;
劉健民
;
曾院介
本發明係有關於一種光感測元件及其製備方法，本發明之光感測元件具有極大蕭特基接面且其包括：一第一導電層；複數金屬奈米線，該每一金屬奈米線之一端係與該第一導電層連接，且該每一金屬奈米線之表面係覆有一半導體層，該半導體層之厚度係為1nm-20nm；以及一第二導電層，係對應該第一導電層而配置，該複數金屬奈米線係配置於該第一導電層與該第二導電層之間，且該第二導電層與該複數金屬奈米線表面之半導體層接觸；其中，該光感測元件係用於感測波長10nm-400nm之紫外光。