Browsing by Issue Date, starting with "2014-12-13"

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The effect of free-standing GaN substrate on carrier localization in ultraviolet InGaN light-emitting diodes
(2014-12-13)
Tsai, Ming-Ta
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Chu, Chung-Ming
;
Huang, Che-Hsuan
;
Wu, Yin-Hao
;
Chiu, Ching-Hsueh
In this study, we have grown 380-nm ultraviolet light-emitting diodes (UV-LEDs) based on InGaN/AlInGaN multiple quantum well (MQW) structures on free-standing GaN (FS-GaN) substrate by atmospheric pressure metal-organic chemical vapor deposition (AP-MOCVD), and investigated the relationship between carrier localization degree and FS-GaN. The micro-Raman shift peak mapping image shows low standard deviation (STD), indicating that the UV-LED epi-wafer of low curvature and MQWs of weak quantum-confined Stark effect (QCSE) were grown. High-resolution X-ray diffraction (HRXRD) analyses demonstrated high-order satellite peaks and clear fringes between them for the UV-LEDs grown on the FS-GaN substrate, from which the interface roughness (IRN) was estimated. The temperature-dependent photoluminescence (PL) measurement confirmed that the UV-LEDs grown on the FS-GaN substrate exhibited better carrier confinement. Besides, the high-resolution transmission electron microscopy (HRTEM) and energy-dispersive spectrometer (EDS) mapping images verified that the UV-LEDs on FS-GaN have fairly uniform distribution of indium and more ordered InGaN/AlInGaN MQW structure. Clearly, the FS-GaN can not only improve the light output power but also reduce the efficiency droop phenomenon at high injection current. Based on the results mentioned above, the FS-GaN can offer UV-LEDs based on InGaN/AlInGaN MQW structures with benefits, such as high crystal quality and small carrier localization degree, compared with the UV-LEDs on sapphire.
夜晚世界的駐守者
(2014-12-14)
張凱翔
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Department of Communication and Technology
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傳播與科技學系
試著進入夜晚的平行時空，你將看到一群被下放到夜晚世界的人們。
十八投不投　民主新觀點
(2014-12-14)
林霈楨
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Department of Communication and Technology
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傳播與科技學系
太陽花學運期間，高中生們展現了對公共議題的高度關注，也讓投票年齡下修至十八歲的爭議再度浮上檯面。
倫理福祉面對面　複製爭議
(2014-12-14)
劉敏慈
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Department of Communication and Technology
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傳播與科技學系
複製技術已有重大突破，製造人類不再只是幻想，但衍生出的問題卻很爭議。
學運女孩　越「政」越亮眼　
(2014-12-14)
黃詩涵
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Department of Communication and Technology
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傳播與科技學系
一位美麗女大生在參與太陽花學運之後休學，並進入台北市市長候選人的競選團隊，成為青年部主任的故事。
一生的「性」福　如何教育
(2014-12-14)
黃苡齊
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Department of Communication and Technology
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傳播與科技學系
根據調查，臺灣學生在性方面的知識明顯不足，性教育在臺灣究竟面臨何種問題？該如何改善？
路痴人生不迷路
(2014-12-14)
郭穎慈
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Department of Communication and Technology
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傳播與科技學系
關於一個路痴不斷迷路，也不斷覓得新體悟的故事。
生活在「外」　處處不容易
(2014-12-14)
杜以翔
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Department of Communication and Technology
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傳播與科技學系
外籍配偶來臺生活處處不容易，不管是在入籍、福利、刻板印象等等都是他們面對的許多難題。
真心良品市集　用心傳遞愛
(2014-12-14)
李恬芳
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Department of Communication and Technology
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傳播與科技學系
「庇護工場真心良品一日市集」內有手作糕點、盆栽和琉璃飾品等，讓身心障礙者的用心被更多人看見。
總編輯的話
(2014-12-14)
侯怡安
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Department of Communication and Technology
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傳播與科技學系
本期為喀報二○四期，共有十六篇稿件。此期喀報與廣袤的社會下所發生的事物息息相關，由多面向去探討各種不同的議題。
為愛而跑　擁抱「異同」
(2014-12-14)
鄭宇茹
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Department of Communication and Technology
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傳播與科技學系
第一屆彩虹路跑，希望透過活動宣揚「婚姻平權」的理念，讓更多人重視這個議題。
讓不讓座　從心出發
(2014-12-14)
余念竹
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Department of Communication and Technology
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傳播與科技學系
讓與不讓之間，探討博愛座各種可能性，並賦予新的定義。
單身無罪　不婚族湧現
(2014-12-14)
陳致穎
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Department of Communication and Technology
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傳播與科技學系
隨著社會的改變，不婚族越來越多，不論是男性或女性，都有自己的考量，無不希望自己可以活得更有精彩。
熱力四射　啦啦隊錦標賽
(2014-12-14)
賴奕安
;
劉雨婕
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Department of Communication and Technology
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傳播與科技學系
二○一四年全國啦啦隊錦標賽，為首次於臺灣舉行的啦啦隊亞洲公開賽，現場氣氛熱鬧、表演精彩萬分。
小氣鬼　人性的真實
(2014-12-14)
陳亞柔
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Department of Communication and Technology
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傳播與科技學系
《小氣鬼》描述了許多世人揣測的社會真實與黑暗面。
凜冽時雨　熾熱搖滾
(2014-12-14)
查爾灣.米吉
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Department of Communication and Technology
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傳播與科技學系
「正因為什麼都不像難以類比，才顯得如此特別。」對於日本音樂來說，凜冽時雨是個特別的存在，極具實驗性的歌曲，不停的挑動聽眾的耳朵，卻又富有極高的動聽度。
玩社團　玩出社會競爭力
(2014-12-14)
黃馨儀
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Department of Communication and Technology
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傳播與科技學系
玩社團不再是被家長侷限的活動，在社團中獲得夥伴，學習堅持的勇氣，學習負責，都成為未來出社會的墊腳石。
時光洗鍊　初心不變
(2014-12-14)
包金
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Department of Communication and Technology
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傳播與科技學系
喜歡的每一個事物，留下當時的自己，面對複雜社會現實衝擊，能尋回最初的心。
Growth orientations of semipolar ZnO on GaN(1 1 (2)over-bar 2)
(2014-12-15)
Shih, Yi-Sen
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Lin, Pei-Yin
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Chen, Jr-Yu
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Chang, Li
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材料科學與工程學系
On semipolar GaN(1 1 (2) over bar 2), epitaxial ZnO grown by chemical vapor deposition can form in two different semipolar orientations as evidenced by transmission electron microscopy and X-ray diffraction. One orientation relationship is shown to be ZnO(1 1 (2) over bar 2)//GaN(1 1 (2) over bar 2) and [(1) over bar 1 0 0](ZnO)//[(1) over bar 1 0 0](GaN) which is expected for ZnO growth on GaN(1 1 (2) over bar 2), while the other is a newly found relationship of ZnO((1) over bar 0 1 (1) over bar)//GaN(0 0 0 2) and [5 (7) over bar 2 (3) over bar](ZnO)//[(1) over bar 1 0 0](GaN). (C) 2014 Elsevier B.V. All rights reserved.
Eigenvalue solvers for three dimensional photonic crystals with face-centered cubic lattice
(2014-12-15)
Huang, Tsung-Ming
;
Hsieh, Han-En
;
Lin, Wen-Wei
;
Wang, Weichung
;
應用數學系
To numerically determine the band structure of three-dimensional photonic crystals with face-centered cubic lattices, we study how the associated large-scale generalized eigenvalue problem (GEP) can be solved efficiently. The main computational challenge is due to the complexity of the coefficient matrix and the fact that the desired eigenvalues are interior. For solving the GEP by the shift-and-invert Lanczos method, we propose a preconditioning for the associated linear system therein. Recently, a way to reformat the GEP to the null space free eigenvalue problem (NFEP) is proposed. For solving the NFEP, we analyze potential advantages and disadvantages of the null space free inverse Lanczos method, the shift-invert residual Arnoldi method, and the Jacobi-Davidson method from theoretical viewpoints. These four approaches are compared numerically to find out their properties. The numerical results suggest that the shift-invert residual Arnoldi method with an initialization scheme is the fastest and the most robust eigensolver for the target eigenvalue problems. Our findings promise to play an essential role in simulating photonic crystals. (C) 2014 Elsevier B.V. All rights reserved.