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研究生:徐兆慶
研究生(外文):CHAO-CHING HSU
論文名稱:石墨烯量子點膽固醇液晶雷射之研究
論文名稱(外文):Study of Graphene Quantum Dot Lasing in Cholesteric Liquid Crystals
指導教授:葉蕙溱
指導教授(外文):Hui-Chen Yeh
學位類別:碩士
校院名稱:國立高雄第一科技大學
系所名稱:電機工程研究所碩士班
學門:工程學門
學類:電資工程學類
論文種類:學術論文
論文出版年:2014
畢業學年度:102
語文別:中文
論文頁數:71
中文關鍵詞:石墨烯量子點膽固醇液晶三明治夾層結構熱退火
外文關鍵詞:Sandwich structureGraphene quantum dotsCholesteric liquid crystalQuantum confinement effect
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石墨烯量子點是由數層石墨烯組成,直徑為數十奈米,表面和側面有數種化
學官能基修飾的準零維球狀奈米粒子,其內部電子在各方向上的運動都受到侷限
而表現出顯著的量子侷限效應和邊緣效應,導致能階不連續,當侷域狀態的電子
電洞對產生輻射復合時,即放出螢光。能階間隙與粒子大小有關,根據不同的合
成方法,石墨烯量子點的螢光可從深紫外到綠色甚至黃色。石墨烯量子點具有良
好的化學穩定性和生物相容性、低毒性、低成本、無光致漂白等優越的特性,在
生醫感測、細胞成像、光電元件等領域有無限的應用潛力。
本研究使用石墨烯量子點做為膽固醇液晶雷射的工作物質,取代傳統的雷射
染料。石墨烯量子點以二片膽固醇液晶夾成三明治結構,調整螺距使二片膽固醇
液晶的反射波段只有一邊重疊。為降低石墨烯量子點膽固醇液晶雷射的輸出能量
閾值,將膽固醇液晶樣品經過熱退火的機制使內部缺陷移除,以減少共振腔的損
耗,並配合石墨烯量子點的最佳濃度,經激發後可產生雷射輸出。
Graphene quantum dots (GQDs) are zero dimensional quasi-spherical nanoparticles with diameter from several nanometers to tens of nanometers, consisting of one or a few graphite layers. GQDs generally possess functional groups decorated at basal plane and lateral edge. Besides the factor of size, these characteristic functional groups provide quantum confinement, and lead to discrete quantum states. The electron-hole pairs within localized states can recombine radiatively and emit luminescence. The energy gap generally depends on the size of the GQDs. The luminescence can be varied from deep ultraviolet to green even yellow by different method for the synthesis of GQDs. Due to their superiority in chemical inertness,excellent biocompatibility, low toxicity, low cost, and resistance to photobleaching,GQDs have wide potential applications in biosensor, bioimaging, and photovoltaic.
In this study, GQDs were used to serve as the active material for cholesteric liquid crystal laser, replacing the conventional laser dyes. GQDs were sandwiched between two cholesteric liquid crystal cells. The pitch of one cholesteric liquid crystal layer was shifted with respect to the other so that only the edges of reflective bands overlapped. To lower the lasing threshold of the sandwich cell, the defects in the cholesteric liquid crystal layers were removed by an annealing process. In addition to reducing the cavity loss, the concentration of GQDs was chosen to get maximum fluorescence. Coherent lasing with narrow spectral width was observed after optical excitation.
目錄
摘要……………………………………………………………………………………...I
Abstract…………………………………………………………………………………II
誌謝…………………………………………………………………………………...III
目錄………………………………………………………………………….…………IV
圖目錄………………………………………………………………….........................VI
表目錄…………………………………………………………………………………IX
第一章、簡介……………………………………………………………………………1
1-1、前言………………………………………………………………………………1
1-2、何謂液晶………………………………………………………………………3
1-3、液晶的分類………………………………………………………………………3
1-4、液晶物理特性……………………………………………………………………12
1-4-1、液晶雙折射性……………………………………………………………12
1-4-2、液晶連續彈性體理論……………………………………………………15
1-4-3、溫度對向列型液晶的影響………………………………………………16
1-4-4、電場對向列型液晶的影響………………………………………………17
第二章、理論介紹……………………………………………………………………19
2-1、膽固醇液晶……………………………………………………………………19
2-1-1、熱退火對於膽固醇液晶的影響…………………………………………19
2-1-2、膽固醇液晶光學特性與雷射機制………………………………………19
2-1-3、膽固醇液晶雷射的缺陷模式…………………………………………….23
2-2、石墨烯量子點…………………………………………………...……….………24
2-2-1、石墨烯簡介…………………………………..............................24
2-2-2、石墨烯量子點簡介……………………………………………………….25
2-2-3、石墨烯量子點的合成…………………………………………………….26
2-3、量子點的特性………………………………..........................26
第三章、實驗方法與過程………………….............................31
3-1、材料介紹…………………………………………………………………………31
3-2、樣品空盒的製作…………………………………………………………………33
3-3、樣品製作…………………………………………………………………………34
3-4、實驗架設………………………………………………………………………...38
第四章、實驗結果與討論…………………………………………………………….40
4-1、石墨烯量子點的吸收與穿透量測………………………………………………40
4-2、石墨烯量子點的螢光量測………………………………………………………41
4-3、三明治夾層樣品的特性量測……………………………………………………44
4-3-1、完美平面螺旋結構的膽固醇液晶樣品………………………………….44
4-3-2、膽固醇液晶樣品的穿透量測…………………………………………….46
4-3-3、灌入石墨烯量子點的三明治夾層樣品穿透頻譜量測………………….47
4-3-4、灌入石墨烯量子點的三明治夾層樣品螢光量測………………………48
4-4、三明治夾層樣品雷射輸出量測…………………………………………………50
第五章、結論與未來展望........................................54
參考文獻...................................................56
[1] H. Kogelnik , C.V. Shank, “Stimulated emission in a periodic structure,” Appl. Phys.
Lett. 18, 152 (1971).
[2] V. I. Kopp, B. Fan, H. K. M. Vithan, A. Z. Genack, “ Low-threshold lasing at the
edge of a photonic stop band in cholesteric liquid crystals,” Optics Letters 23,
1707-1709 (1998).
[3] M. H. Song, N. Y. Ha, K. Amemiya, B. Park, Y. Takanishi, K. Ishikawa, J. W. Wu, S.
Nishimura, T. Toyooka, H. Takezoe, “Defect-Mode Lasing with Lowered Threshold
in a Three-Layered Hetero-Cholesteric Liquid-Crystal Structure,” Advanced
Materials 18, 193–197 (2006).
[4] Chun-Ta Wang, Tsung-Hsien Lin, “Multi-wavelength laser emission in dye-doped
photonic liquid crystals,” Vol. 16, No. 22 / OPTICS EXPRESS (2008).
[5] G. Chilaya, A. Chanishvili, G. Petriashvili, R. Barberi, G. Cipparrone, A. Mazzulla,
M. P. Dc Santo, H. Sellame, M. A. Matranga, “Single Mode Lasing in Multilayer
Sandwiched SystemsConsisting of Cholesteric Liquid Crystals and Dye Solution,”
XV International Symposium on Advanced Display Technologies, Proc. of SPIE
Vol. 6637, 66370M, (2007).
[6] Dengyu Pan, Jingchun Zhang, Zhen Li, Minghong Wu, “Hydrothermal Route for
Cutting Graphene Sheets into Blue-Luminescent Graphene Quantum Dots,”
Advanced Materials 22, 734–738 (2010).
[7] B. Bahadur, “Liquid Crystals : Applications and Uses,” Vol. 1, World Scientific,
Singapore (1990).
[8] L. M. Blinov, V. G. Chigrinov, “Electrooptic Effects in Liquid Crystal Materials,”
Springer-Verlag Publishing Co., New York (1994).
[9] P. G. de Gennes and J. Prost, “The Physics of Liquid Crystals”, 2nded., Clarendon
Press, Oxford (1993).
[10] Andrew J. Lovinger, Karl R. Amundson, Don D. Davis, “Morphological
Investigation of UV-Curable Polymer-Dispersed Liquid-Crystal (PDLC) Materials,”
Chem. Mater. 6, 1726 (1994).
[11] Grant R. Fowles, “Introduction to Modern Optics”, 2nded., University of Utah,
New York (1975).
[12] 朱自強、王仕璠與蘇顯渝,『現代光學教程』,四川大學出版社,成都 (1990).
[13] A. Yariv, “Quantum Electronics”, John Wiley & Sons Press, New York (1989).
[14] Iam-Choon Khoo, “Liquid Crystals-Physical Properties and Nonlinear Optical
Phenomena,” John Wiley & Sons Press, New York (1995).
[15] C. W. Oseen, “The theory of liquid crystals,” Trans. Faraday Soc. 29, 883 (1933).
[16] H. Zocher, “The effect of a magnetic field on the nematic state,” Trans. Faraday
Soc. 29, 945 (1933).
[17] F. C. Frank, Discuss. “I. Liquid crystals. On the theory of liquid crystals,” Faraday
Soc. 25, 19 (1958).
[18] Ryotaro Ozaki, Toshikazu Shinpo, and Hiroshi Moritake, “Improvement of
orientation of planar cholesteric liquid crystal by rapid thermalprocessing,”
Applied Physics Letters 92, 163304 (2008).
[19] 田景瑞,熱退火處理對膽固醇液晶平面結構之改善,國立彰化師範大學物理學系博士論文,中華民國九十六年六月。
[20] Jonathan P. Dowling, Michael Scalora, Mark J. Bloemer and Charles M. Bowden,
“The photonic band edge laser: A new approach to gain enhancement,” J. Appl.
Phys. 75, 1896 (1994).
[21] Harry Coles, Stephen Morris, “Liquid-crystal lasers,” Nature Photonics 4, 676–685
(2010).
[22] 維基百科-石墨烯
http://zh.wikipedia.org/wiki/%E7%9F%B3%E5%A2%A8%E7%83%AF
[23] Kian Ping Loh, Qiaoliang Bao, Goki eda, manish chhowalla, “Graphene oxide as a
chemically tunable platformfor optical applications,” nature chemistry dOi:
10.1038/nchem.907 , 23 November (2010).
[24] Pan D,Zhang J, Li Z, Wu M, “Hydrothermal Route for Cutting Graphene Sheets
into Blue-Luminescent Graphene Quantum Dots,” Adv. Mater. 22, 734-738 (2010).
[25] Shoujun Zhu, Junhu Zhang, Chunyan Qiao, Shijia Tang, Yunfeng Li, Wenjing
Yuan, Bo Li, Lu Tian, Fang Liu, Rui Hu, Hainan Gao, Haotong Wei, Hao Zhang,
Hongchen Sun, Bai Yang, “Strongly green-photoluminescent graphene quantum
dots for bioimaging applicationsw,” Chem. Commun. 47, 6858–6860 (2011).
[26] Vinay Gupta, Neeraj Chaudhary, Ritu Srivastava, Gauri Datt Sharma, Ramil
Bhardwaj, Suresh Chand, “Luminscent Graphene Quantum Dots for Organic
Photovoltaic Devices,” J. Am. Chem. Soc. 133, 9960–9963 (2011).
[27] 張立德,奈米材料和奈米結構,滄海圖書出版(2003)。
[28] 奈米結構材料科學,郭正次,全華科技圖書出版(2004)。
[29] J. W. D. Callister, “Materials Science and Engineering an Introduction,” 5th ed.,John Wiley, New York, 616-623 (2000).
[30] 王世敏,奈米材料原理與製備,五南圖書出版(2004)。
[31] 王文軒,硒化鎘量子點的液相化學合成與特性之研究,逢甲大學材料科學研
究所碩士論文,中華民國九十七年七月。
[32] Sigma-Aldrich Quantum Dot
http://www.sigmaaldrich.com/materials-science/nanomaterials/quantum-dots.html
[33] Quantum Dots — Nanosys Inc
http://www.nanosysinc.com/what-we-do/quantum-dots/
[34]黃柏元,可電與可全光控之染料摻雜液晶隨機雷射之研究,國立成功大學光電
科學與工程研究所碩士論文,中華民國九十九年七月。
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