Browsing by Issue Date, starting with "2013-10-07"

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Low resistance copper-based ohmic contact for AlGaN/GaN high electron mobility transistors
(2013-10-07)
Wong, Yuen-Yee
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Chen, Yu-Kong
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Maa, Jer-Shen
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Yu, Hung-Wei
;
Tu, Yung-Yi
Ti/Al/Ni/Cu ohmic contact for AlGaN/GaN structure has been fabricated. The Ni layer played an important role in achieving low specific contact resistance (r(c)), smooth morphology, and excellent edge acuity. With a 50-angstrom Ni layer, a r(c) of 1.35 x 10(-6) Omega-cm(2) and a root-mean-square roughness of 7.65 nm have been realized. The characterization results indicated that no evidence of Cu diffusion into the semiconductor layers. The formation of Al-Cu and Ti-Cu alloys might have confined the Cu within the ohmic metal. In the absence of gold, the surface roughening caused by Au-Al alloy in conventional Ti/Al/Ni/Au structure was also prevented. (C) 2013 AIP Publishing LLC.
交大e-News第149期
(2013-10-07)
Secretariat
;
國立交通大學秘書室
Lower operation voltage in dual-frequency cholesteric liquid crystals based on the thermodielectric effect
(2013-10-07)
Hsiao, Yu-Cheng
;
Lee, Wei
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影像與生醫光電研究所
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Institute of Imaging and Biomedical Photonics
Dual-frequency cholesteric liquid crystal (DFCLC) devices characteristically require high operation voltage, which hinders their further development in thin-film-transistor driving. Here we report on a lower-voltage switching method based on the thermodielectric effect. This technique entails applying a high-frequency voltage to occasion dielectric oscillation heating so to induce the increase in crossover frequency. The subsequent change in dielectric anisotropy of the DFCLC allows the switching, with a lower operation voltage, from the planar state to the focal conic or homeotropic state. The temperature rise incurred by the dielectric heating is described. (C)2013 Optical Society of America
Improvement of bandgap homogeneity in Cu(In,Ga)Se-2 thin films using a modified two-step selenization process
(2013-10-07)
Wang, Yi-Chih
;
Shieh, Han-Ping D.
;
光電工程學系
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顯示科技研究所
;
Department of Photonics
A modified two-step selenization has been demonstrated to overcome inhomogeneous gallium distribution, an issue to lower energy bandgap in the space-charge region as well as cell efficiency. It was found that incorporating selenium into conventional precursors could accelerate the formation of CuInGaSe2 phase in the selenization to accordingly suppress the diffusion effect of gallium. By introducing a pre-heating treatment, this selenization enhanced the bandgap distribution with a back-surface field and an increase of bandgap in the space-charge region, consequently improving open circuit voltage (V-OC) by 25% and cell efficiency by 55%, respectively. (C) 2013 AIP Publishing LLC.
Low-voltage high-speed programming/erasing floating-gate memory device with gate-all-around polycrystalline silicon nanowire
(2013-10-07)
Lee, Ko-Hui
;
Tsai, Jung-Ruey
;
Chang, Ruey-Dar
;
Lin, Horng-Chih
;
Huang, Tiao-Yuan
A gate-all-around polycrystalline silicon nanowire (NW) floating-gate (FG) memory device was fabricated and characterized in this work. The cross-section of the NW channels was intentionally made to be triangular in shape in order to study the effects of the corners on the device operation. Our results indicate that the channel corners are effective in lowering the programming and erasing (P/E) operation voltages. As compared with the charge-trapping type devices, a larger memory window is obtained with the FG scheme under low-voltage P/E conditions. A model considering the nature of the charge storage medium is proposed to explain the above findings. (C) 2013 AIP Publishing LLC.
Electrically driven green, olivine, and amber color nanopyramid light emitting diodes
(2013-10-07)
Chang, Shih-Pang
;
Chang, Jet-Rung
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Sou, Kuok-Pan
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Liu, Mei-Chun
;
Cheng, Yuh-Jen
We report the fabrication and studies of electrically driven green, olivine, and amber color nanopyramid GaN light emitting diodes (LEDs). InGaN/GaN multiple quantum wells (MQWs) were grown on the nanopyramid semipolar facets. Compared with the commonly used (0001) c-plane MQWs, the semipolar facet has lower piezoelectric field, resulting in much faster radiative recombination efficiency. This is important for high In content MQWs. The measured internal quantum efficiencies for green, olivine, and amber color LED are 30%, 25%, and 21%, respectively. The radiative and non-radiative lifetime of the semipolar MQWs are also investigated. (C) 2013 Optical Society of America
Generation of pseudonondiffracting optical beams with superlattice structures
(2013-10-07)
Tsou, C. H.
;
Wu, T. W.
;
Tung, J. C.
;
Liang, H. C.
;
Tuan, P. H.
We demonstrate an approach to generate a class of pseudonondiffracting optical beams with the transverse shapes related to the superlattice structures. For constructing the superlattice waves, we consider a coherent superposition of two identical lattice waves with a specific relative angle in the azimuthal direction. We theoretically derive the general conditions of the relative angles for superlattice waves. In the experiment, a mask with multiple apertures which fulfill the conditions for superlattice structures is utilized to generate the pseudonondiffracting superlattice beams. With the analytical wave functions and experimental patterns, the pseudonondiffracting optical beams with a variety of structures can be generated systematically. (C) 2013 Optical Society of America
失落與哀悼的異鄉旅行：柳宗元《永州八記》與奧芬巴哈《霍夫曼的故事》
(2013-10-07)
鄭聖勳
;
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。
Nonvolatile Flash Memory Based on Biologically Integrated Hierarchical Nanostructures
(2013-10-08)
Sano, Ken-Ichi
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Miura, Atsushi
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Yoshii, Shigeo
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Okuda, Mitsuhiro
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Fukuta, Megumi
The first six peptides of multifunctional titanium binding peptide-1 bestowed recombinant L-ferritin, minT1-LF, was genetically engineered and used to fabricate multilayered nanoparticle architecture. The multifunctionality of minT1-LF enables specific binding of nanoparticle-accommodated minT1-LF to the silicon substrate surface and wet biochemical fabrication of gate oxide layer by its biomineralization activity. Three-dimensional (3D) nanoparticle architecture with multilayered structure was fabricated by the biological layer-by-layer method and embedded in a metal oxide-semiconductor device structure as a charge storage node of a flash memory device. The 3D-integrated multilayered nanoparticle architecture successfully worked as a charge storage node in flash memory devices that exhibited improved charge storage capacity compared with that of a conventional monolayer structure device.
Role of the Comonomeric Units in Reaching Linear Backbone, High Solid-State Order and Charge Mobilities in Heptacyclic Arene-Based Alternating Copolymers
(2013-10-08)
Lee, Tien-Hsin
;
Wu, Kuan-Yi
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Lin, Tai-Yen
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Wu, Jhong-Sian
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Wang, Chien-Lung
Unpredictable trends of charge mobility (mu) in multicyclic heteroarenes-contained polymers remain an obstacle in designing high performance polymers used in polymeric field effect transistors (PFETs). The roles of the comonomeric units in reaching high hole mobility (mu(h)) of copolymers containing a heptacyclic arene unit, dithienocyclopentacarbazole (DTCC) were investigated in this study. A series of four DTCC-based alternating copolymers, PDTCC-1T, PDTCC-3T, PDTCC-BDT, and PDTCC-TT, were synthesized from the Pd-catalyzed copolymerizations between DTCC and comonomeric units including thioene (1T), terthiophene (3T), benzodithiophene (BDT) and thienothiophene (TT) units. Among the four DTCC-based alternating copolymers, highest mobility of 1.36 X 10(-2) cm(2) s(-1) was reached in PDTCC-3T. Optoelectronic and 2D-WAXD studies revealed that strong electronic interaction and highly ordered solid-state structure were only observed in PDTCC-3T. It is attributed to the combination of two axisymmertric units, DTCC and 3T, linearized the polymer backbone, leading to a compact solid-state packing and high mu(h), while centrosymmertic comonomeric units, BDT and TT curved the polymer backbones of PDTCC-BDT and PDTCC-TT, which decreases solid-state order and mu(h). Furthermore, the short axisymmeritric 1T although results in a linear backbone of PDTCC-1T, comparing to 3T, it is too short to effectively reduce interchain steric hindrance caused by the solubilizing octyl chains on DTCC. Thus, effective pi-pi stacking is hindered in PDTCC-1T, resulting in low mu(h). The macroscopic performances of mu(h)s agreed well with the optoelectronic and 2D-WAXD studies. It is concluded that the linear backbone of DTCC copolymers is the prerequisite to reach ordered solid-state packing, which facilitate effective charge transport, and it depends on the prudent choose on the symmetry of the comonomeric unit. In addition, balance between the solubility and adequate crowdedness of lateral side chains is essential for a PFET material to be not only easily processed, but also effectively pi-pi stack.
Red and green fluorosulfide phosphor, preparation method and white-light emitting diodes thereof
(2013-10-08)
Chen Teng-Ming
;
Wu Yun-Chen
Novel red and green fluorosulfide phosphors have a chemical formula of (A1-x-yCexBy)SF, wherein A and B are both trivalent metal ions, 0
A New Pentacyclic Indacenodiselenophene Arene and Its Donor-Acceptor Copolymers for Solution-Processable Polymer Solar Cells and Transistors: Synthesis, Characterization, and Investigation of Alkyl/Alkoxy Side-Chain Effect
(2013-10-08)
Chang, Huan-Hsuan
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Tsai, Che-En
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Lai, Yu-Ying
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Liang, Wei-Wei
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Hsu, So-Lin
A pentacyclic indacenodiselenophene (IDS) arene was synthesized via intramolecular Friedel-Craft cyclization of the selenophene moieties. This IDS framework was used as a model system to investigate the alkyl/alkoxy side-chain effect by preparing IDS-OCH8 and IDS-C-6, where the side chains on the sp(3) carbon in the cyclopentadienyl ring are 4-octyloxyphenyl groups and 4-hexylphenyl groups, respectively. The SnIDS-OCH8 and Sn-IDS-C-6 monomers were copolymerized with 4,7dibromo-2,1,3-benzothiadiazole (BT), 4,7-diiodo-5,6-difluoro-2,1,3-benzothiadiazole (FBT) and 1,3-dibromothieno[3,4-dpyrrole-4,6-dione (TPD) acceptor monomers by Stil le polycondensation to afford five new IDS-based donor acceptor alternating copolymers, PIDSBT-OCH8, PIDSBTC6) PIDSFBT-OCH8, PIDSFBT-C-6, and PIDSTPD-C-6. Despite the fact that the octyloxy and hexyl side chains play a negligible role in the optical and electrochemical properties of the resulting polymers, the solar cell performance is highly associated with the side chains of the polymers. Under similar device fabrication conditions, the PIDSBT-C-6 and PIDSFBT-C-6-based devices showed much improved efficiencies than the corresponding PIDSBT-OCH8, and PIDSFBT-OCH8-based devices (2.6% and 1.9% vs 3.8% and 3.9%). The improvement is mainly the result of much enhanced J(sc) values. Consistently, PIDSBT-C-6 and PIDSFBT-C-6 exhibited much higher FET hole mobilites than the corresponding PIDSBT-OCH8, and PIDSFBT-OCH8. These results clearly revealed that the 4-hexylphenyl group is a more suitable side chain than the 4-octyloxyphenyl group in the IDS system, and the side-chain dependent mobility of the polymers is the dominating factor to determine the photocurrents and efficiencies of PSCs. PIDSBT-C-6 exhibited a high hole mobility of 0.08 cm(2) V-1 s(-1) and PIDSTPD-C-6:PC71BM (1:4 in wt %)-based solar cell with 5 v% chloronaphthalene (CN) delivered a V-oc of 0.92 V, a J(sc) of 9.77 mA/cm(2), an FF of 51%, and a highest PCE of 4.6%. This work not only discloses a new selenophene-containing ladder-type IDS structure and its copolymers but also provides useful insights into the allcyl/alkoxy side-chain effect for future design of conjugated polymers.
Localization-delocalization transition of the instantaneous normal modes of liquid water
(2013-10-09)
Huang, Ban-Chiech
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Chang, Cheng-Hung
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物理研究所
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Institute of Physics
Despite the fact that the localization-delocalization transition (LDT) widely exists in wave systems, quantitative studies on its critical and multifractal properties are mainly focused on solids. In this work, these properties are investigated on the vibrational motions of liquid water. Simulations of up to 18 000 molecules on the flexible extended simple point charge water model provide nearly 10(6) instantaneous normal modes. They are shown to undergo an LDT close to the translational transition and exhibit multifractal fluctuations while approaching the LDT. In combination with finite-size scaling, multifractal analysis predicts the critical frequency Im(omega(c)) approximate to -131.6 cm(-1) for unstable modes at room temperature. The estimated critical exponent nu approximate to 1.60 is close to those of other calculated systems in the same Wigner-Dyson class. At the LDT, the fractal spectrum f (alpha) and the most probable local vibrational intensity alpha(mc) approximate to 4.04 coincide with those of the Anderson model, which might be additional universal properties of LDT in more general wave systems. The results extend the validity of the multifractal scaling approach beyond Andersonian systems to a Hessian system.
Liver-Specific Expressions of HBx and src in the p53 Mutant Trigger Hepatocarcinogenesis in Zebrafish
(2013-10-09)
Lu, Jeng-Wei
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Yang, Wan-Yu
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Tsai, Su-Mei
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Lin, Yueh-Min
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Chang, Pen-Heng
Hepatocarcinogenesis is a multistep process that starts from fatty liver and transitions to fibrosis and, finally, into cancer. Many etiological factors, including hepatitis B virus X antigen (HBx) and p53 mutations, have been implicated in hepatocarcinogenesis. However, potential synergistic effects between these two factors and the underlying mechanisms by which they promote hepatocarcinogenesis are still unclear. In this report, we show that the synergistic action of HBx and p53 mutation triggers progressive hepatocellular carcinoma (HCC) formation via src activation in zebrafish. Liver-specific expression of HBx in wild-type zebrafish caused steatosis, fibrosis and glycogen accumulation. However, the induction of tumorigenesis by HBx was only observed in p53 mutant fish and occurred in association with the up-regulation and activation of the src tyrosine kinase pathway. Furthermore, the overexpression of src in p53 mutant zebrafish also caused hyperplasia, HCC, and sarcomatoid HCC, which were accompanied by increased levels of the signaling proteins p-erk, p-akt, myc, jnk1 and vegf. Increased expression levels of lipogenic factors and the genes involved in lipid metabolism and glycogen storage were detected during the early stages of hepatocarcinogenesis in the HBx and src transgenic zebrafish. The up-regulation of genes involved in cell cycle regulation, tumor progression and other molecular hallmarks of human liver cancer were found at later stages in both HBx and src transgenic, p53 mutant zebrafish. Together, our study demonstrates that HBx and src overexpression induced hepatocarcinogenesis in p53 mutant zebrafish. This phenomenon mimics human HCC formation and provides potential in vivo platforms for drug screening for therapies for human liver cancer.
2-Alkyl-5-thienyl-Substituted Benzo[1,2-b:4,5-b ']dithiophene-Based Donor Molecules for Solution-Processed Organic Solar Cells
(2013-10-09)
Patra, Dhananjaya
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Huang, Tzu-Yen
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Chiang, Chao-Cheng
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Maturana, Ramon Orlando Valencia
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Pao, Chun-Wei
In this study, we have strategically designed and convergently synthesized two novel, symmetrical, and linear A-D-A-type pi-conjugated donor molecules (TBDTCNR, TBDTCN), each containing a planar electron-rich 2-octylthiene-5-yl-substituted benzodithiophene (TBDT) unit as the core, flanked by octylthiophene units and end-capped with electron-deficient cyanoacetate (CNR) or dicyanovinyl (CN) units. We thoroughly characterized both of these materials and investigated the effects of the end groups (CNR, CN) on their optical, electrochemical, morphological, and photovoltaic properties. We then fabricated solution-processed bulk heterojunction organic solar cells incorporating TBDTCNR and TBDTCN. Among our tested devices, the one containing TBDTCNR and [6,6]-phenyl-C-61-butyric acid methyl ester in a 1:0.40 ratio (w/w) exhibited the highest power conversion efficiency (5.42%) with a short-circuit current density (J(sc)) of 9.08 mA cm(-2), an open circuit voltage (V-oc) of 0.90 V, and an impressive fill factor (FF) of 0.66 under AM 1.5G irradiation (100 mW cm(-2)). The FFs of these solution-processed small-molecule organic solar cells (SMOSCs) are outstanding when compared with those recently reported for benzodithiophene (BDT)-based SMOSCs, because of the high crystallinity and excellent stacking properties of the TBDT-based compounds.
LIPID CARRIER FOR DELIVERY OF BIOACTIVE SUBSTANCE AND PHARMACEUTICAL COMPOSITION
(2013-10-10)
Liao Kuang-Wen
;
Liu Yen-Ku
;
Chen Chia-Hung
The present invention provides a lipid carrier for delivering of a bioactive substance. The lipid carrier includes a lipid layer, a positive charged polymer and a surface active polymer. The positive charged polymer and the surface active polymer are respectively distributed on the lipid layer by non-covalent bonds. The present invention also provides a pharmaceutical composition. The present invention is advantageous for delivering bioactive substance efficiently.
CHOLESTERIC LIQUID CRYSTAL DISPLAY DEVICE AND METHOD FOR DRIVING THE SAME
(2013-10-10)
CHEN Yu-Hsien
;
Chen Huang-Ming
;
Liu Sheng-Fa
;
Chiang Mei-Tsao
;
Ciou Bao-Sian
A cholesteric liquid crystal display device includes a first substrate, a second substrate, a cholesteric liquid crystal layer and a plurality of nano particles. The first substrate includes a first alignment layer. The second substrate includes a second alignment layer. The cholesteric liquid crystal layer is disposed between the first and second alignment layers. The nano particles are disposed on a surface of one of the first and second alignment layers, and located between the one of the first and second alignment layers and the cholesteric liquid crystal layer.
感測裝置
(2013-10-11)
鄭泗東
;
周伯謙
;
林育丞
一種感測裝置，包括基座、柱體、桿件、感測元件及驅動模組。基座具有承載面且適於承載物件於承載面上。柱體配置於承載面上。桿件具有兩端點及位於兩端點之間的樞接部。樞接部沿實質上平行於承載面的軸線樞接於柱體。感測元件配置於桿件上而位於一端點與樞接部之間。感測元件位於基座與物件之間。驅動模組配置於桿件與基座之間。驅動模組驅動桿件沿軸線相對柱體樞轉，感測元件隨著桿件的樞轉而移近或移離物件。
電阻式隨機存取記憶體以及其製作方法
(2013-10-11)
張俊彥
;
張耀峰
一種電阻式記憶體元件，包含：一第一電極；一第二電極，配置於該第一電極上方；一介電層，配置於該第一電極與該第二電極之間；以及電極混合系統層，配置於該第一電極與該介電層之間，亦或配置於該第二電極與該介電層之間，其中該電極混合系統層係由一過渡態金屬元素所構成。當該電極混合系統層配置於該第一電極與該介電層之間時，該電極混合系統層可於化學氣相沈積(CVD)該介電層時所含的熱與氧之製程環境中，而自發性地於該第一電極與該介電層之間形成一由氧化鐵(FeO)或氧化鈷(CoO)等過渡金屬氧化薄層所構成之第一電阻轉態層；另一種方式為藉由額外之退火製程，使得過渡態金屬元素與該介電層間形成由過渡金屬氧化薄層所構成之第一電阻轉態層於該第一電極與該介電層之間；當該電極混合系統層配置於該第二電極與該介電層之間時，則藉由額外之退火製程，使得過渡態金屬元素與該介電層間形成由過渡態金屬氧化薄層所構成之第二電阻轉態層於該第二電極與該介電層之間。
具有瑕疵補償之單軸控制輸入陀螺儀系統。
(2013-10-11)
陳宗麟
;
紀建宇
;
李嘉緯
本發明為一種具有瑕疵補償之單軸控制輸入陀螺儀系統，係包含一陀螺儀及一狀態觀察裝置；陀螺儀包含一機械結構，機械結構的動態行為可利用複數個系統參數及複數個動態方程式加以描述，該些系統參數包含陀螺儀的質量、主軸剛性係數、跨軸剛性係數、主軸阻尼係數、跨軸阻尼係數及一物體的待量測角速度。陀螺儀輸入一單軸控制訊號，而輸出複數個系統動態於兩軸，且單軸控制訊號包含至少兩個頻率訊號。狀態觀察裝置耦接於陀螺儀，並以陀螺儀系統動態輸出作為輸入，藉以回授補償於狀態觀察裝置，並於具機械結構瑕疵狀況下量測出待量測角速度。