Browsing by Author "Lin, Shih-Wei"

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Cationic Iridium Complexes with Intramolecular pi-pi Interaction and Enhanced Steric Hindrance for Solid-State Light-Emitting Electrochemical Cells
(2012-11-19)
Chen, Hsiao-Fan
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Hung, Wen-Yi
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Chen, Shou-Wei
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Wang, Ting-Chih
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Lin, Shih-Wei
Cationic iridium complexes incorporated 4,5-diaza-9,9'-spirobifluorene as N<^>N ancillary ligands, in which one (2) or two (3) phenyl groups were introduced onto 4,5-diazafluorene to afford intraligand pi-pi interactions. The X-ray crystal structures of complexes 2 and 3 show that the pendant phenyl ring forms strong intramolecular face-to-face pi-stacking with the difluorophenyl ring of the cyclometalated ligand with distances of 3.38 angstrom for complex 2 and 3.40 and 3.46 angstrom for complex 3. This pi-pi stacking interaction minimizes the expansion of the metal ligand bonds in the excited state, resulting in a longer device lifetime in the light-emitting electrochemical cell (LEC) devices.
Efficient solid-state white light-emitting electrochemical cells based on phosphorescent sensitization
(2012-11-21)
Su, Hai-Ching
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Chen, Hsiao-Fan
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Chen, Po-Hsien
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Lin, Shih-Wei
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Liao, Chih-Teng
Efficient phosphorescent sensitized white light-emitting electrochemical cells (LECs) based on a blue-emitting phosphorescent cationic transition metal complex (CTMC) doped with a red-emitting fluorescent dye are demonstrated. Blue phosphorescence and phosphorescence-sensitized red fluorescence contribute to white emission. Furthermore, the microcavity effect of the device structure is utilized to suppress the green part of the electroluminescence (EL) spectrum of the blue-emitting phosphorescent metal complex (1) via destructive interference. Hence, more saturated blue EL emission can be obtained. When combined with saturated red emission, white EL emission with Commission Internationale de l'Eclairage coordinates approaching (0.33, 0.33) can be obtained without the need for saturated deep-blue emitting CTMCs. Peak external quantum efficiency and power efficiency of the phosphorescence sensitized white LECs are up to 7.9% and 15.6 lm W-1, respectively. These efficiencies are among the highest reported for white LECs and reveal that phosphorescent sensitization is useful for improving device efficiencies of white LECs.
Gold nanoparticle-decorated graphene oxides for plasmonic-enhanced polymer photovoltaic devices
(2014)
Chuang, Ming-Kai
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Lin, Shih-Wei
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Chen, Fang-Chung
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Chu, Chih-Wei
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Hsu, Chain-Shu
In this work, gold nanoparticle/graphene oxide (AuNP/GO) nanocomposites are synthesized and used as anodic buffer layers in organic photovoltaic devices (OPVs). The application of thiol-terminated polyethylene glycol as a capping agent prevents the aggregation of AuNPs on the GO surface and further improves the solubility and stability of these nanomaterials in solutions. When AuNP/GO nanomaterials served as the buffer layers, they introduced localized surface plasmon resonance (LSPR) in the OPVs, leading to noticeable enhancements in the photocurrent and the efficiencies of the OPVs. We attribute the primary origin of the improvement in device performance to local field enhancement induced by the LSPR. We anticipate that this study might open up new avenues for constructing plasmon-enhancing layers on the nanoscale to improve the performance of solar cells.
High-quality planar light emitting diode formed by induced two-dimensional electron and hole gases
(2014-02-24)
Van-Truong Dai
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Lin, Sheng-Di
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Lin, Shih-Wei
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Lee, Yi-Shan
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Zhang, Yin-Jie
A high-quality planar two-dimensional p-i-n light emitting diode in an entirely undoped GaAs/AlGaAs quantum well has been fabricated by using conventional lithography process. With twin gate design, two-dimensional electron and hold gases can be placed closely on demand. The electroluminescence of the device exhibit high stability and clear transition peaks so it is promising for applications on electrically-driven single photon sources. (C) 2014 Optical Society of America
High-sensitivity two-terminal magnetoresistance devices using InGaAs/AlGaAs two-dimensional channel on GaAs substrate
(2016-04-25)
Wu, Di-Cheng
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Pan, You-Wei
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Wu, Jenq-Shinn
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Lin, Shih-Wei
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Lin, Sheng-Di
We demonstrate experimentally the two-terminal magnetic sensors exhibiting an extraordinary magneto-resistance effect by using an InGaAs quantum well channel with a metal-shunting structure. A high magneto-resistance of 17.3% and a sensitivity of 488.1 Omega/T have been obtained at 1 T and room temperature with our geometrical design. The two-contact configuration and the high-mobility electron transistor-compatible epitaxy structure make the devices promising for high-sensitivity magnetic sensing integration and applications. Published by AIP Publishing.
Improved Exact Methods for Solving No-Wait Flowshop Scheduling Problems With Due Date Constraints
(2018-01-01)
Ying, Kuo-Ching
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Lu, Chung-Cheng
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Lin, Shih-Wei
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運輸與物流管理系註：原交通所+運管所
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Department of Transportation and Logistics Management
The no-wait flowshop scheduling problem with hard due date constraints is critical to operations in many industries, such as plastic, chemical, and pharmaceutical manufacturing. However, to date, there is a lack of effective optimization algorithms for this NP-hard problem. This paper develops a new mixed integer linear programming (MILP) model and a two-phase enumeration algorithm to improve the best-so-far exact methods for solving this problem with the objective of minimizing the makespan. A comprehensive computational experiment is performed to compare the performances of the discussed exact methods. The computational results demonstrate that the proposed MILP model and the two-phase enumeration algorithm significantly outperform the best-so-far optimization methods, and the (sub-) optimal solutions to several unsolved instances from the literature are reported.
Lateral Two-Dimensional p-i-n Diode in a Completely Undoped GaAs/AlGaAs Quantum Well
(2013-01-01)
Van-Truong Dai
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Lin, Sheng-Di
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Lin, Shih-Wei
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Wu, Jau-Yang
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Li, Liang-Chen
A lateral two-dimensional p-i-n junction in an entirely undoped GaAs/AlGaAs quantum well has been fabricated. The optical and electrical characteristics of the junction are reported. The threshold voltage of the junction and the electroluminescence spectrum of the quantum well confirm the formation of the lateral two-dimensional junction. (C) 2013 The Japan Society of Applied Physics
Magnetotransport in an aluminum thin film on a GaAs substrate grown by molecular beam epitaxy
(2011)
Lo, Shun-Tsung
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Chuang, Chiashain
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Lin, Sheng-Di
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Chen, Kuang Yao
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Liang, Chi-Te
Magnetotransport measurements are performed on an aluminum thin film grown on a GaAs substrate. A crossover from electron- to hole-dominant transport can be inferred from both longitudinal resistivity and Hall resistivity with increasing the perpendicular magnetic field B. Also, phenomena of localization effects can be seen at low B. By analyzing the zero-field resistivity as a function of temperature T, we show the importance of surface scattering in such a nanoscale film.
Minimizing the Sum of Makespan and Total Weighted Tardiness in a No-Wait Flowshop
(2018-01-01)
Lin, Shih-Wei
;
Lu, Chung-Cheng
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Ying, Kuo-Ching
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運輸與物流管理系註：原交通所+運管所
;
Department of Transportation and Logistics Management
This paper presents a cloud theory-based iterated greedy (CTIG) algorithm for solving the no-wait flowshop scheduling problem (NWFSP) with the objective of minimizing the sum of makespan and total weighted tardiness. The performance of the proposed CTIG algorithm is evaluated by comparing its computational results to those of the best-to-date meta-heuristic algorithm, particle swarm optimization (PSO), as presented in this paper. The experimental results concerning two sets of benchmark problem instances in this paper demonstrate that the CTIG algorithm obtains more (near) optimal solution in less computational time than the PSO algorithm. The computational results in this paper fill the research gap in the development of a novel algorithm to improve the solution quality in the case of the NWFSP with the objective of minimizing the sum of makespan and total weighted tardiness.
Optimal Allocation of Cashiers and Pharmacists in Large Hospitals: A Point-Wise Fluid-Based Dynamic Queueing Network Approach
(2018-01-01)
Lu, Chung-Cheng
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Lin, Shih-Wei
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Chen, Hui-Ju
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Ying, Kuo-Ching
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運輸與物流管理系註：原交通所+運管所
This paper presents an optimization model for determining the optimal time-varying numbers of cashiers and pharmacists in a large hospital. The objective of this model is to minimize the weighted sum of the waiting cost incurred by patients and the operating costs incurred by the hospital. A point-wise fluid based approximation approach is adopted to construct a dynamic queuing network that takes into account time-varying (or non-stationary) arrivals of patients and describes time-varying queue lengths. The dynamic queuing network is then encapsulated in the optimization model that determines the optimal time-varying numbers of cashiers and pharmacists. A test problem instance is designed based on a large hospital in the city of Taipei, and the MINOS solver of GAMS is applied to solve the problem instance. Sensitivity analyses are also conducted to examine the impacts of customer arrival rates and service rates on the waiting cost and operational cost. Numerical results show that the optimization model can provide an optimal allocation of manpower that significantly reduces both waiting and operating costs.
Pure electron-electron dephasing in percolative aluminum ultrathin film grown by molecular beam epitaxy
(2015-02-18)
Lin, Shih-Wei
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Wu, Yue-Han
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Chang, Li
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Liang, Chi-Te
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Lin, Sheng-Di
We have successfully grown ultrathin continuous aluminum film by molecular beam epitaxy. This percolative aluminum film is single crystalline and strain free as characterized by transmission electron microscopy and atomic force microscopy. The weak anti-localization effect is observed in the temperature range of 1.4 to 10 K with this sample, and it reveals that, for the first time, the dephasing is purely caused by electron-electron inelastic scattering in aluminum.
Single-crystalline aluminum film for ultraviolet plasmonic nanolasers
(2016-01-27)
Chou, Bo-Tsun
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Chou, Yu-Hsun
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Wu, Yen-Mo
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Chung, Yi-Cheng
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Hsueh, Wei-Jen
Significant advances have been made in the development of plasmonic devices in the past decade. Plasmonic nanolasers, which display interesting properties, have come to play an important role in biomedicine, chemical sensors, information technology, and optical integrated circuits. However, nanoscale plasmonic devices, particularly those operating in the ultraviolet regime, are extremely sensitive to the metal and interface quality. Thus, these factors have a significant bearing on the development of ultraviolet plasmonic devices. Here, by addressing these material-related issues, we demonstrate a low-threshold, high-characteristic-temperature metal-oxide-semiconductor ZnO nanolaser that operates at room temperature. The template for the ZnO nanowires consists of a flat single-crystalline Al film grown by molecular beam epitaxy and an ultrasmooth Al2O3 spacer layer synthesized by atomic layer deposition. By effectively reducing the surface plasmon scattering and metal intrinsic absorption losses, the high-quality metal film and the sharp interfaces formed between the layers boost the device performance. This work should pave the way for the use of ultraviolet plasmonic nanolasers and related devices in a wider range of applications.
Single-Machine Scheduling with Learning Effects and Maintenance: A Methodological Note on Some Polynomial-Time Solvable Cases
(2017-01-01)
Ying, Kuo-Ching
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Lu, Chung-Cheng
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Lin, Shih-Wei
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Chen, Jie-Ning
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運輸與物流管理系註：原交通所+運管所
This work addresses four single-machine scheduling problems (SMSPs) with learning effects and variable maintenance activity. The processing times of the jobs are simultaneously determined by a decreasing function of their corresponding scheduled positions and the sum of the processing times of the already processed jobs. Maintenance activity must start before a deadline and its duration increases with the starting time of the maintenance activity. This work proposes a polynomial-time algorithm for optimally solving two SMSPs to minimize the total completion time and the total tardiness with a common due date.
Spin-orbit-coupled superconductivity
(2014-06-25)
Lo, Shun-Tsung
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Lin, Shih-Wei
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Wang, Yi-Ting
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Lin, Sheng-Di
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Liang, C. -T.
Superconductivity and spin-orbit (SO) interaction have been two separate emerging fields until very recently that the correlation between them seemed to be observed. However, previous experiments concerning SO coupling are performed far beyond the superconducting state and thus a direct demonstration of how SO coupling affects superconductivity remains elusive. Here we investigate the SO coupling in the critical region of superconducting transition on Al nanofilms, in which the strength of disorder and spin relaxation by SO coupling are changed by varying the film thickness. At temperatures T sufficiently above the superconducting critical temperature T-c, clear signature of SO coupling reveals itself in showing a magneto-resistivity peak. When T < T-c, the resistivity peak can still be observed; however, its line-shape is now affected by the onset of the quasi two-dimensional superconductivity. By studying such magneto-resistivity peaks under different strength of spin relaxation, we highlight the important effects of SO interaction on superconductivity.