臺灣博碩士論文加值系統

近年來，在共軛高分子單分子與超薄膜的研究中發現，藉由機械拉伸、薄膜除潤、或製程溶劑揮發，使高分子鏈經歷機械拉伸，而使其被迫處於分子拘束狀態，此時分子鏈段上之激子困縛(exciton trapping)下降，使發光效率有非常明顯的提升;同時，因界面電場而致的激子猝熄，也會在機械應力作用之下減小甚至消失。本研究繼續探討此應力作用，將rGO摻入MEH-PPV高分子中，使用PS(polystyrene)作為基材拉伸。我們發現rGO能有效地造成激子的猝熄，而使摻入rGO的MEH-PPV/PS薄膜之發光效率下降。但在拉伸之後，其PL放光隨著機械應變而提升，甚至超過未加rGO的MEH-PPV/PS薄膜之應力效益，證明機械應力已產生作用，不但提升共軛高分子的發光效率，並且有效地減少激子在rGO附近的猝熄現象。我們利用原子力顯微鏡分析拉伸之應力分佈，並利用雷射掃描式共軛焦螢光顯微鏡，顯示此應力增益與猝熄下降之行為。

In recent years, conjugated polymer and ultrathin film were found that molecule can be constrained by stretched mechanism, dewetting process, or solvent annealing process. In this case, the trapped excitons decrease on the molecular segment. This effect significantly increases photoluminescence efficiency and reduces the quenching on the E-field interface. Our work focus on stress effects of MEH-PPV/PS thin film with doping rGO.We found rGO effectively quenches excitons that dropped the photoluminescence efficiency of doped rGO polymer film. However, the PL was enhanced with mechanical strain. The enhancement is higher than without polymer film without doping rGO. The results represent that mechanical stress not only improves the emission efficiency but also reduces exciton quenching near rGO. The distribution of tensile stress was obversed by atomic force microscopy. The PL enhancement and reduced quenching were studied by confocal fluorescence microscopy.

書名頁.....................................................i
論文口試審定書.............................................ii
授權書...................................................iii
摘要.....................................................vii
Abstract.................................................ix
誌謝......................................................xi
目錄.....................................................xii
表目錄...................................................xvi
圖目錄..................................................xvii
一、緒論...................................................1
1-1簡介....................................................1
1-2螢光猝熄效應(Fluorescence quench effect).................2
1-3研究動機................................................4
二、文獻回顧................................................6
2-1 石墨烯（Graphene）......................................6
2-1-1石墨烯制備方法.........................................7
1.膠帶剝離法................................................8
2.化學氣相沉積法............................................9
3.碳化矽表面外延生長法......................................11
4.切割奈米碳管法...........................................12
5.化學氧化還原法...........................................12
6.微波法..................................................15
2-2共軛高分子(Conjugated Polymers).........................15
2-2-1 MEH-PPV分子構型及其性質...............................16
2-2-2 Exciton、Excimer、Exciplexes和Polaron pair..........19
2-2-3交連(cross-link)與交纏網路(entanglement network)......20
1.交連(cross-link)........................................20
2.交纏網路(entanglement network)...........................20
2-3共軛高分子的拉伸.........................................21
2-3-1高分子薄膜機械性質.....................................22
1.纖化區的介紹.............................................22
2.微縮頸機制...............................................25
三、實驗方法...............................................28
3-1實驗材料................................................28
3-1-1共軛高分子與石墨烯.....................................28
3-1-2有機溶劑..............................................29
3-1-3實驗基材..............................................30
3-2實驗方法................................................30
3-2-1 MEH-PPV/PS/rGO薄膜製備...............................30
3-2-2 MEH-PPV/PS/rGO薄膜拉伸實驗...........................32
3-3實驗儀器................................................33
3-3-1光學顯微鏡(Optical microscopy)........................33
3-3-2光致發光光譜儀(Photoluminescence spectroscopy)........34
3-3-3原子力探針顯微鏡(Atomic force microscopy)..............36
3-3-4紫外-可見光光譜儀(Ultraviolet–visible spectroscopy)....39
四、拉伸機器設計............................................41
4-1拉伸模具設計需求.........................................41
4-2 拉伸模具設計...........................................41
4-2-1拉伸平臺..............................................41
4-2-2底座設計..............................................42
4-2-3墊片設計..............................................44
五、結果與討論.............................................45
5-1 摻入rGO高分子薄膜試驗...................................45
5-2 拉伸高分子薄膜之試驗....................................49
5-2-1共軛高分子薄膜表面形貌.................................50
5-2-2共軛高分子薄膜厚度與纖化區之觀察.........................53
5-2-3 共軛高分子薄膜拉伸之纖化區的機械性質探討.................56
5-3共軛高分子薄膜拉伸之螢光增益之探討.........................59
5-3-1螢光增益探討..........................................59
5-3-2 量子效率之探討(Quantum efficiency)...................62
5-3-3 雷射掃描式共軛焦螢光顯微鏡之探討(PL mapping)............64
六、結論...................................................69
七、參考文獻...............................................70

[1]Burroughes.,et al, “Light-emitting diodes based on conjugated polymers.” Nature, Vol. 347, 539-541, (1990)
[2]Gustafsson.,et al, “Flexible light-emitting diodes made from soluble conducting polymers.” Nature, Vol. 357, 477-479, (1992)
[3]Braun.,et al, “Visible light emission from semiconducting polymer diodes. ” Applied Physics Letters, Vol. 58, (1991)
[4]He.,et al, “Efficient Polymer Light-Emitting Diodes Using Conjugated Polymer Blends. ” Applied Physics Letters, Vol. 80, 1891-1893, (2002)
[5]Hass.,et al, “The growth and morphology of epitaxial multilayer grapheme”, Science, Vol. 20, 323-202 , (2008)
[6]Novoselov.,et al, “Electric Field Effect in Atomically Thin Carbon FilmsScience, ” ,Science, Vol. 306, 666-669, (2004)
[7]Geim.,et al, “Nobel Prize for grapheme. ”, Nature Materials, Vol. 6, 183-191,(2007)
[8]Li.,et al, “Large-Area Synthesis of High-Quality and Uniform Graphene Films on Copper Foils.”, Science, Vol. 324, 1312-1314,(2009)
[9]Bae.,et al, “Roll-to-roll production of 30-inch graphene films for transparent electrodes.”, Nature Nanotechnology, Vol. 5, 574-578, (2010)
[10]Kobayashi.,et al, “Production of a 100-m-long high-quality graphene transparent conductive film by roll-to-roll chemical vapor deposition and transfer process.”, Applied Physics Letters , Vol. 102, 023112, (2013)
[11]Brumfiel, G. “Nanotubes cut to ribbons.” Nature, (2009)
[12]Jang.,et al, “Process for producing nano-scaled graphene plates.” “US20050271574 A1,(2005)
[13]Staudenmaier. L., “Verfahren zur Darstellung der Graphitsäure.”, Berichte der deutschen chemischen Gesellschaft, Vol. 31, 1481-1487, (1898)
[14]Schniepp.,et al, “Functionalized Single Graphene Sheets Derived from Splitting Graphite Oxide. ”, J. Phys. Chem. B, Vol. 17, 8535-8539,(2006)
[15]Guang.,et al, “Chinese Journal of Inorganic Chemistry. ”, (2011)
[16]Geng.,et al, “Preparation of graphite nanoplatelets and graphene sheets. ”, Vol. 336, 592-598 ,(2009)
[17]Zhou.,et al, “Reducing Graphene Oxide via Hydroxylamine: A Simple and Efficient Route to Graphene.”, J. Phys. Chem. C , Vol. 115, 11957-11961,(2011)
[18]Schwartz B. J., “Conjugated Polymers: What makes a chromophore?”, Nature Materials, Vol. 7, 427-428, (2008)
[19]Collini. E.,et al, “Coherent intrachain energy migration ina conjugated polymer at room temperature. ”, Science, Vol. 323, 369-373, (2009)
[20]B. J. Schwartz, “Conjugated polymers as molecular materials: how chain conformation and film morphology influence energy transfer and interchain interactions. ”, Vol. 54, 141-172 , (2003)
[21]J. L. Brédas, “Excitons Surf Along Conjugated Polymer Chains. ”, Science, Vol. 323, 348-349, (2009)
[22]Jenekhe S. A.,et al. “Excimers and exciplexes of conjugated polymers.”, Science, Vol. 265, 765-768, (1994)
[23]Jenekhe S. A.,et al, “ENHANCEMENT OF LUMINESCENCE IN POLYMER NANOCOMPOSITES.”, Chemistry of materials, Vol. 6, 1906-1909, (1994)
[24]童冠博, “奈米塑性形變引致共軛高分子單分子發光之重大增益現象與研究”, 清華大學材料系碩士論, (2008)
[25]Michler G. H., “Crazes in amorphous polymers I. Variety of the structure of crazes and classification of different types of crazes.”, Colloid & Polymer Science, Vol. 267, 377-388, (1989)
[26]Krupenkin T. N., Fredrickson G. H., “Crazing in Two and Three Dimensions. 1. Two-Dimensional Crazing Macromolecules.”, Vol. 32, 5029-5035, (1999)
[27]Kramer E. J., Microscopic and Molecular Fundamentals of Crazing, Advances in Polymer Science, Vol. 52-53, 1-56, (1983)
[28]Yang.,et al., “Micro-necking operative during crazing in polymer glasses.”, Macromolecules, Vol. 26, 1767-1773, (1993)
[29]J. H. Lin, A. C. M. Yang, “Crazing Micro-mechanism in Glassy Atactic Polystyrene and Its Blends with Poly(2,6-dimethyl-1,4-diphenyl oxides) by AFM.”, Macromolecules, Vol. 34, 3698-3705, (2001)
[30]Yang.,et al, “Drawing of microshear deformation zones in glassy polymers: Poly(phenylene oxide) (PPO).”, Journal of Polymer Science Part B: Polymer Physics, Vol. 34, 1141-1145, (1996)
[31]Lin.,et al, “Super-plastic behavior of the brittle polymer film in multilayer systems.”, Journal of Materials Science, Vol. 35, 4231-4242, (2000)
[32]Yang.,et al, “Craze fibril stability and breakdown in polystyrene.”, Macromolecules, Vol. 19, 2010-2019, (1986)
[33]Yang.,et al, “Crazes in diluted entanglement networks of polystyrene.”, Macromolecules, Vol. 19, 2020-2027, (1986)
[34]林志維, “奈米碳管與玻態高分子奈米形變交互作用以及光電性質研究”, 清華大學材料系博士論文, (2010)
[35]Khan.,et al, “High-Concentration Solvent Exfoliation of Graphene.”, Vol. 6, 864-871, (2010)
[36]Fu.,et al,“Effects of particle size, particle/matrix interface adhesion and particle loading on mechanical properties of particulate-polymer composites.”, Composites: Part B, Vol. 39, 933-961, (2008)
[37]Guangjin.,er al, “6.5% Efficiency of Polymer Solar Cells Based on poly (3‐hexylthiophene) and Indene‐C60 Bisadduct by Device Optimization.”, Advanced Materials, Vol. 22, 4355-4358, (2010)
[38]Zhicai, et al., “Simultaneous Enhancement of Open‐Circuit Voltage, Short‐Circuit Current Density, and Fill Factor in Polymer Solar Cells.”, Advanced Materials, Vol. 23, 4636-4643, (2011)
[39]Lee.,et al, “Processing additives for improved efficiency from bulk heterojunction solar cells.”, Journal of the American Chemical Society, Vol. 130, 3619-3623, (2008)
[40]Yu., et al. “Polymer photovoltaic cells: enhanced efficiencies via a network of internal donor-acceptor heterojunctions.”, Science-AAAS-Weekly Paper Edition, Vol. 270, 1789-1790, (1995)
[41]Mayukh.,et al, “Incremental optimization in donor polymers for bulk heterojunction organic solar cells exhibiting high performance.”, Journal of Polymer Science Part B: Polymer Physics, Vol. 50, 1057-1070, (2012)
[42]Goutam.,et al, “Photoluminescence Quenching of Poly (3-hexylthiophene) by Carbon Nanotubes.”, The Journal of Physical Chemistry C, Vol. 116, 8196-8201,(2012):.
[43]Ran.,et al, “Study on photoluminescence quenching and photostability enhancement of MEH-PPV by reduced graphene oxide.” The Journal of Physical Chemistry C, Vol.116, 23053-23060,(2012)
[44]李培煒, “共軛高分子薄膜之分子堆積、除潤運動與拉伸的發光增益研究.”, 清華大學材料系碩士論文 , (2011)