Browsing by Issue Date, starting with "2019-05-27"

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Enhancement in speed and responsivity of uni-traveling carrier photodiodes with GaAs0.5Sb0.5/In0.53Ga0.47As type-II hybrid absorbers
(2019-05-27)
Naseem
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Ahmad, Zohauddin
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Chao, Rui-Lin
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Chang, Hsiang-Szu
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Ni, C-J
We demonstrate a top-illuminated high-speed uni-traveling carrier photodiode (UTC-PD) with a novel design in the p-type absorber, which call effectively shorten the photon absorption depth at telecommunication wavelengths (1.31 similar to 1.55 mu m) and further enhance the bandwidth-efficiency product of UTC-PD. In our proposed new UTC-PD structure, the p-type In0.53Ga0.47As absorption layer is replaced by the type-II GaAs0.5Sb0.5 (p)/In0.53Ga0.47As (i) hybrid absorber. Due to the narrowing of the bandgap and enhancement of the photo-absorption process at the type-II interface between the GaAs0.5Sb0.5 and In0.53Ga0.47As layers, our device shows an over 16.7% improvement in the responsivity compared with that of UTC-PD with the same thickness of pure In0.53Ga0.47As absorber (0.7 mu m) and a zero optical coupling loss. Our demonstrated device with a simple top-illuminated structure offers a large active mesa (25 mu m). a wide optical-to-electrical (O-E) bandwidth (33 GHz), a high responsivity (0.7 A/W), and a high saturation current (>5 mA) under 1.31 mu m optical wavelength. These promising results suggest that our proposed PD structure can fundamentally overcome the trade-off among bandwidth. efficiency. and device active diameter of high-speed PDs. (C) 2019 Optical Society of America under the terms of the OSA Open Access Publishing Agreement
Visible light communication and positioning using positioning cells and machine learning algorithms
(2019-05-27)
Chuang, Yu-Cheng
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Li, Zhi-Qing
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Hsu, Chin-Wei
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Liu, Yang
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Chow, Chi-Wai
We propose and experimentally demonstrate a practical visible light position (VLP) system using repeated unit cells and machine learning (ML) algorithms. ML is employed to increase the positioning accuracy. Algorithms of the 2nd-order regression ML model and the polynomial trilateral ML model are discussed. More than 80% of the measurement data have position error within 4 cm when using the 2nd-order regression ML model, while the position error is within 5 cm when using the polynomial trilateral ML model. (C) 2019 Optical Society of America under the terms of the OSA Open Access Publishing Agreement
A nonlinear optical switch induced by an external electric field: inorganic alkaline-earth alkalide
(2019-05-28)
Li, Bo
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Peng, Daoling
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Gu, Feng Long
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Zhu, Chaoyuan
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應用化學系分子科學碩博班
Exploring a new type of nonlinear optical switch molecule with excess electron character is extremely important for promoting the application of excess electron compounds in the nonlinear optical (NLO) field. Here, we report external electric field (EEF) induced second-order NLO switch molecules of inorganic alkaline-earth alkalides, M(NH3) 6Na2 (M = Mg or Ca). The centrosymmetric structure of M(NH3) 6Na2 is destroyed in the presence of an EEF, and then a long-range charge transfer process occurs. It has been found that excess electrons are gradually transferred from one Na atom to the other Na atom through the inorganic metal cluster M(NH3) 6. Finally, the excess electrons are completely located on one of the two Na atoms. In particular, the electronic contribution of the static first hyperpolarizability (b e 0) for M(NH3) 6Na2 exhibits a large significant difference when the EEF is switched on. The b e 0 value of M(NH3) 6Na2 is 0 when EEF = 0, while the peak b e 0 values are 5.95 106 (a. u.) for Mg(NH3) 6Na2 (EEF = 58 10 4 (a. u.)) and 1.83 107 (a. u.) for Ca(NH3) 6Na2 (EEF = 53 10 4 (a. u.)). This work demonstrates that the compounds M(NH3) 6Na2 can serve as potential candidates for NLO switches.
High energy density of all-screen-printable solid-state microsupercapacitors integrated by graphene/CNTs as hierarchical electrodes
(2019-05-28)
Chih, Jui-Kung
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Jamaluddin, Anif
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Chen, Fuming
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Chang, Jeng-Kuei
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Su, Ching-Yuan
Microsupercapacitors (MSCs) are alternative power sources that have the potential to fulfill the increasing demand for wearable and on-chip electronics as they are small and lightweight, and show extremely high charge-discharge rates and power densities, and have high flexibility. However, the critical challenge of recent MSCs is the limitation of low energy density and complicated fabrication processes that are high cost and time-consuming. Here, we reported an all-screen-printable method for fabricating all-solid (including electrolytes) and flexible MSCs by rationally designed composite electrodes with electrochemically exfoliated graphene (ECG) and long single-walled carbon nanotubes (CNTs). This method demonstrated to be a facile and scalable route to fabricate and assemble MSCs in a cost-effective manner and with high throughput. As a result, the resulting MSC devices exhibit an areal capacitance of 7.7 mF cm(-2) and volumetric capacitance of 77.3 F cm(-3), with an excellent cyclic stability of >99% after 15000 cycles; this can be attributed to the creation of a high diffusion path and the promotion of ion transport capability. The cell exhibits energy and power densities of 10.7 mW h cm(-3) and 3.17 W cm(-3), respectively. Moreover, there was negligible degradation in capacitance when subjected to bending deformation with radius reduced to 0.5 mm, indicating excellent mechanical flexibility and operation stability. Further, the output voltage and current can be rationally designed by multiple connections of MSC devices in series and parallel to fulfill the demands of various applications. This study provides a scalable and cost-effective method to produce solid-state MSCs with high energy density, which paves the way for their applications in potential wearable devices.
High-Uniformity Planar Mini-Chip-Scale Packaged LEDs with Quantum Dot Converter for White Light Source
(2019-05-29)
Chen, Lung-Chien
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Tien, Ching-Ho
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Chen, De-Fu
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Ye, Zhi-Ting
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Kuo, Hao-Chung
This study proposes a novel direct-lit mini-chip-scale packaged light-emitting diode (mini-CSPLED) backlight unit (BLU) that used quantum dot (QD) film, diffusion plate, and two prism films to improve brightness uniformity. Three different luminous intensity units, 120 degrees mini-CSPLED, 150 degrees mini-CSPLED, and 180 degrees mini-CSPLED with different emission angle structures were fabricated using a CSP process. In terms of component characteristics, although the 180 degrees mini-CSPLED light output power is about loss 4% (at 10mA) compared with 150 degrees mini-CSPLED, it has a large emission angle that forms a planar light source that contributes to improving the BLU brightness uniformity and reduced quantity of LEDs at the same area. In terms of BLU analysis, the blue mini-CSPLEDs with different emission angles excite the different QD film thicknesses; the chromaticity coordinates conversion to the white light region. The BLU brightness increases as the QD film thickness increases from 60, 90, and 150m. This result can achieve a brightness uniformity of 86% in a 180 degrees mini-CSPLED BLU + 150-m-thick QD films as compared to the 120 degrees mini-CSPLED BLU and 150 degrees mini-CSPLED BLU.
Bio-Inspired Flexible Fluoropolymer Film for All-Mode Light Extraction Enhancement
(2019-05-29)
Liang, Renli
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Hu, Run
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Long, Hanling
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Huang, Xinyu
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Dai, Jiangnan
Enhancing the light extraction efficiency is a prevalent but vital challenge for most solid-state lighting technologies, especially for deep ultraviolet light-emitting diodes (DUV-LEDs). In this paper, inspired by the micro-structure of the butterfly's eye, we propose and fabricate a flexible fluoropolymer film (FFP film) to tackle this issue for all-mode, full-wavelength light extraction enhancement for most solid-state lighting technologies compatibly. The experimental results demonstrate that compared with one mounted with a smooth FFP film, the light output power of DUV-LED is enhanced up to 26.7% by mounting the FFP film with 325 nm radius nanocones at a driving current of 200 mA. Importantly, thanks to the super-flexible feature of the FFP film, it can both cover the top surface and sidewalls of the DUV-LED chip, leading to the improvement of transverse electric and transverse magnetic mode light extraction by 20.5 and 21.8%, respectively. Finite element analysis (FEA) simulations of the electric field distribution of DUV-LEDs with the FFP film reveal the underlying physics. The present strategy is proposed from the view of the packaging level, which is cost-effective, able to be manufactured at a large scale, and compatible with the solid-state lighting technologies.
戰況激烈精彩，水運會展現青春活力
(國立陽明大學, 2019-05-31)
陽明電子報編輯小組
每年校慶的重頭戲──水上運動大會，5月17日熱鬧登場。從一早8:30開始，連續將近10小時，32項比賽接連上陣，讓游泳健身館水花四濺...
【補充工作新動力】愛與慾的糾葛～音樂劇《鐘樓怪人》賞析
(國立陽明大學, 2019-05-31)
陽明電子報編輯小組
【生技咖啡館】6月份～微流體晶片之商品化與其體外檢測應用
(國立陽明大學, 2019-05-31)
陽明電子報編輯小組
【藥物科學院職涯講座III】TCRA臨床試驗領域相關工作職涯分享
(國立陽明大學, 2019-05-31)
陽明電子報編輯小組
神農坡與陽明2.0的距離──107學年第2學期【早安，神農坡】
(國立陽明大學, 2019-05-31)
陽明電子報編輯小組
這學期的「早安神農坡」，5月22日上午在剛整修好的大禮堂舉行，主題是「神農坡與陽明2.0的距離」；延續歷年來知性與感性、公益與...
三社聯合舞展《永舞指境》
(國立陽明大學, 2019-05-31)
陳婕翎
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陽明電子報編輯小組
準備已久的三社聯合舞展《永舞指境》，由民舞社、國標社與手語社帶來的「舞」光十色表演，結合現代潮流、舞者的熱情還有絕美的燈光氣氛，為觀眾帶來一場藝術盛宴。光看著精美的節目表，就讓人覺得這次的舞展不虛此行！
陽明、交大、中研院成立「數位醫學聯盟」，提升防治疾病精準度
(國立陽明大學, 2019-05-31)
陽明電子報編輯小組
陽明5月14日宣布成立「數位醫學聯盟」（Digital Medicine Alliance），結合交通大學數據科學與工程研究所、中央研究院資訊科學研...
【勞維俊老師電影《莫失莫忘》】公開首映
(國立陽明大學, 2019-05-31)
陽明電子報編輯小組
國際產學聯盟輔導補助計畫說明會，鼓勵研發成果商品化
(國立陽明大學, 2019-05-31)
陽明電子報編輯小組
為協助醫療機構將臨床研發成果商品化，本校國際產學聯盟透過科技部產學司委託執行的國際產學聯盟計畫，於4月10日在振興醫院國際會...
【合校事宜公聽會】(三)～(五)
(國立陽明大學, 2019-05-31)
陽明電子報編輯小組
【107學年度畢業周】系列活動
(國立陽明大學, 2019-05-31)
陽明電子報編輯小組
【107學年度畢業典禮】
(國立陽明大學, 2019-05-31)
陽明電子報編輯小組
陽明GLORIA引介醫療AI創新應用，串起數位醫學新機
(國立陽明大學, 2019-05-31)
陽明電子報編輯小組
陽明大學國際產學聯盟（GLORIA）以「Digital Medicine」為題，5月14日盛大舉辦國際級論壇暨產學媒合會，邀請科技部、衛福部、台中...
美麗新視界～視覺障礙學生特徵及輔具運用
(國立陽明大學, 2019-05-31)
劉容孜
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陽明電子報編輯小組