本研究係於具有三噻吩烯基作為共軛側鏈之二維共軛高分子的主鏈中導入缺電子（A）單元之benzothiadiazole (BTD)單體，並分別與推電子（D）單元之5,5'-bis(trimethylstannyl)-2,2'-bithiophene (BT-bisSn)或(3,3'-difluoro-2,2'-bithiophe
ne-5,5'-diyl)bis(trimethylstannane) (DFBT-bisSn)單體，利用Stille coupling進行共聚合形成三種低能隙共軛高分子（OAP01、OAP02與OAP03），並針對它們的光學、電化學及結晶性質進行分析研究。合成出之中間物、單體以及最終的共軛高分子均應用核磁共振光譜儀(proton nuclear magnetic resonance、carbon-13 nuclear magnetic resonance；1H NMR、13C NMR) 及質譜儀 (mass spectrometry；MS) 對其分子結構進行鑑定，並以凝膠滲透層析 (gel permeation chromatography；GPC) 測得它們的分子量特性。
由於導入D-A單元於共軛主鏈中，三種二維共軛高分子產物之能隙均比poly(3-hexylthiophene) (P3HT)者小，而且也多了側鏈的在短波長處的吸收峰。其中，OAP02具有最窄的能隙，為1.51 eV。因為benzothiadiazole (BTD)單元的存在，它們的HOMO能階均較P3HT低。OAP01透過在推電子單元中導入氟之拉電子官能基來增加電子親和力，以薄膜態測得之HOMO能階為-5.04 eV，OAP02則透過去除隔離物(π-spacer)之方式，使得其HOMO能階為-5.00 eV，OAP03則綜合以上兩點，得到了三者之中最低的HOMO能階，為-5.40 eV。較低之HOMO能階特性將有助於提升太陽能電池元件之開環電壓。在結晶性質的部分，三個高分子均具有良好的lamella方向烷基規則排列，除此之外， OAP01由於導入具高度平面性的DFBT，為當中最具有π-π堆疊性的高分子 (π-π stacking distance：3.64 Å)。初步將OAP01應用為異質混摻 (bulk heterojunction；BHJ) 太陽能電池之電子予體材料，搭配PCBM為電子受體材料，其能量轉換效率 (energy conversion efficiency；PCE) 達6.61 %。實驗結果可讓我們對於benzothiadiazole (BTD) 衍生物之二維共軛高分子、主鏈導入π共軛結構以及導入具有含氟官能基修飾之(3,3'-difluoro-2,2'-bithiophene-5,5'-diyl)bis(trimethylstannane) (DFBT-BisSn) 推電子單元有更進一步的認識與了解，有助於未來設計高性能之有機高分子太陽能材料。

This study focused on developing novel low-bandgap organic materials by copolymerizing an electron-deficient monomer, benzothiadiazole (BTD) anchored with terthiophene-vinylene moieties as conjugated side chains, and an electron-rich monomer, 5,5'-bis(trimethylstannyl)-2,2'-bithiophene (BT-bisSn) or (3,3'-difluoro-2,2'-bithiophene-5,5'-diyl)bis(trimethylstannane) (DFBT-bisSn) with or without two thiophene rings as a conjugated spacer in the backboneviathe Stille polycondensation route toproduce three conjugated polymers, namely OAP01~03, in which 3-(2-octyldodecyl)thiophene moieties were bonded to the BTD unit to increase their solubility as well as molecular weight. All intermediates and final polymer products were structurally characterized by NMR spectroscopy (1H NMR, 13C NMR) and mass spectrometry. Gel permeation chromatography (GPC),X-ray diffraction (XRD) and ultraviolet–visible spectrometer (UV/Vis) were applied to determine these polymers’ molecular weight characteristics, crystallinity and optical properties, respectively. Moreover, their electronic properties were then investigated by cyclic voltammetry (CV) and photoelectron spectroscopy in air (PESA).

(1) Mitch, J. Commercializing low-cost Solar Cells. Chemical & Engineering News 2016, 30-34.
(2) http://www.nrel.gov/ncpv/images/efficiency_chart.jpg
(3) Kallmans, H.; Pope, M. Photovoltaic Effect in Organic Crystals. J. Chem. Phys. 1958, 30, 585.
(4) 林彥豪: 以二噻吩并噻二唑衍生物為主幹之共軛小分子與高分子之合成與性質探討. 國立台灣大學高分子科學與工程學研究所碩士論文, 2014.
(5) Tang, C. W. Two-layer organic photovoltaic cell. Appl. Phys. Lett. 1986, 48, 183-185.
(6) Sariciftci, N. S.; Braun, D.; Zhang, C.; Srdanov, V. I.; Heeger, A. J.; Stucky, G.; Wudl, F. Semicounducting polymer-buckminsterfullerene heterojunctions: Diodes, Photodiodes and photovoltaic cells. Appl. Phys. Lett. 1993, 62, 585-587.
(7) G, Yu.; J, Gao.; Hummelen, J.; Wudl, F.; Heeger, A. J. Science 1995, 270, 1789.
(8) Yuze, Lin.; Yongfang, Li.; Xiaowei, Zhan. Small molecule semiconductors for high-efficiency organic photovoltaics. Chem. Soc. Rev. 2012, 41, 4245-4272.
(9) Yen-Ju, Cheng.; Sheng-Hsiung, Yang.; Chain-Shu, Hsu. Synthesis of Conjugated Polymers for Organic Solar Cell Applications. Chem. Rev. 2009, 5868-5923.
(10) Andre, Bessette.; Garry, S.Hanan. Design,synthesis and photophysical studies of dipyrromethene-based material: insights into their applications in organic photovoltaic devices. Chem. Soc. Rev. 2014, 3342-3405.
(11) Scharber, M.; Mühlbacher, D.; Koppe, M.; Denk, P.; Waldauf, C.; Heeger, A. J.; Brabec, C. Design Rules for Donors in Bulk-Heterojunction Solar Cells-Towards 10 % Energy-Conversion Efficiency. Adv. Mater. 2006, 18, 789.
(12) W. Ma.; C. Yang.; X. Gong.; K. Lee.; Heeger. A. J. Thermally Stable, Efficient Polymer Solar Cells with Nanoscale Control of the Interpenetrating Network Morphology. Adv. Funct. Mater. 2005, 15, 1617-1622.
(13) Jianhui, Hou.; Lijun, Huo.; Chang, He.; Chunhe, Yang.; Yongfang, Li. Synthesis and Absorption Spectra of Poly(3-(phenylenevinyl)thiophene)s with Conjugated Side Chains. Macromolecules 2006, 39, 594-603.
(14) Zhi-Guo, Zhang.; Siyusn, Zhhang.; Jie, Min.; Chaohua, Chui.; Jing, Zhang.; Maojie, Zhang.;Yongfang, Li. Conjugated Side-Chain Isolated Polythiophene:Synth
esis and Photovoltaic Application. Macromolecules 2012, 45, 113-118.
(15) Sih-Hao, Liao.; Hong-jyun, Jhuo.; Yu-Shen, Cheng.; Show-An, Chen. Fullerene Derivative-Doped Zinc Oxide Nanofilm as the cathode of Inverted Polymer Solar Cells With Low-Bandgap Polymer (PTB7-Th) for High Performance. Adv. Mater. 2013, 25, 4766-4771.
(16) Yongye, Liang.; Danqin, Feng.; Yue, Wu.; Szu-Ting, Tsai.; Gang, Li.; Claire, Ray; Luping, Yu. Highly Efficient Solar Cell Polymers Developed via Fine-Tuning of Structural and Electronic Properties. J. Am. Chem. Soc. 2009, 131, 7792-7799.
(17) Jannic, Wolf.; Federico, Cruciani.; Abdulrahman, E. Ladbban.; Pierre, M. Beauju
ge. Wide Band-Gap 3,4-Difluorothiophene-Based Polymer with 7 % Solar Cell Effici
ency: An Alternative to P3HT. Chem. Mater. 2015, 27, 4184-4187.
(18) Jea-Woong, Jo.; Seunghwan, Bae.; Feng, Liu.; Thomas, P. Russell.; Won-Ho, Jo. Comparison of Two D-A Type Polymers with Each Being Fluorinated on D and A Unit for High Performance Solar Cells. Adv. Funct. Mater. 2015, 25, 120-125.
(19) Jea-Woong, Jo.; Jae-Woong, Jung.; Eui-Hyuk Jung.; Hyungju, Ahn.; Tae-Joo, Shi
n.; Won-Ho Jo. Fluorination on both D and A units in D-A type conjugated copolyme
rs based on difluorobithiophene and benzothiadiazole for highly efficient polymer sol
ar cells. Energy Environ. Sci. 2015, 8, 2427-2434.
(20) Zhenguo, Wang.; Zuojia, Li.; Jiang, Liu.; Jun, Mei.; Kai, Li.; Ying, Li.; Qiang, Peng. Solution-Processable Small Molecules for High-Performance Organic Solar Cells with Rigidly Fluorinated 2,2’-Bithiophene Central Cores. ACS Appl. Mater. Interfaces 2016, 8, 11639-11648.
(21) Shaoqing, Zhang.; Yunpeng, Qin.; Mohammad, A. U.; Bomee, Jang.; Wenchao, Zhao.; Delong, Liu.; Han-Young Woo.; Jianhui, Hou. A Fluorinated Polythiophene Derivative with Stabilized Backbone Conformation for Highly Efficient Fullerene and Non-Fullerene Polymer Solar Cells. Macromolecules 2016, 49, 2993-3000.
(22) Smith, M. B.; Jerry, M. March's Advanced Organic Chemistry: Reactions, Mechanisms, and Structure (6th ed.). 2007.
(23) Goebel, M. T.; Marvel, C. S. The oxidation of Grignard reagents. J. Am. Chem. Soc. 1933, 55, 1693-1696.
(24) Milstein, D.; Stille, J. K. A general, selective, and facile method for ketone synthesis from acid chlorides and organotin compounds catalyzed by palladium. J. Am. Chem. Soc.1978, 100, 3636-3638.
(25) Casado, A. L.; Espinet, P. On the Configuration Resulting from Oxidative Addition of RX to Pd(PPh3)4 and the Mechanism of the cis-to-trans Isomerization of [PdRX(PPh3)2] Complexes (R = Aryl, X = Halide). Organometallics 1998, 17, 954-959.
(26) Casado, A. L.; Espinet, P. Mechanism of the Stille Reaction. 1. The Transmetalation Step. Coupling of R1I and R2SnBu3 Catalyzed by trans-[PdR1IL2] (R1 = C6Cl2F3; R2 = Vinyl, 4-Methoxyphenyl; L = AsPh3). J. Am. Chem. Soc.1998, 120, 8978-8985.
(27) Espinet, P.; Echavarren, A. M. The Mechanisms of the Stille Reaction. Angew. Chem. 2004, 43, 4704-4734.
(28) Farina, V.; Krishnamurthy, V.; Scott, W. J. The Stille Reaction. Organic Reactions 2004.
(29) Williams, Dudley H.; Fleming, Lan. Spectroscopic Methods in Organic Chemi
stry; McGraw-Hill Book Company (UK) Limited 1989.
(30) 蕭全佑: 含三噻吩共軛側鏈之聚噻吩高分子:合成、性質及其光伏應用. 國立台灣大學高分子科學與工程學研究所博士論文, 2014.
(31) Y. Li. Molecular Design of Photovoltaic Materials for Polymer Solar Cells: Toward Suitable Electronic Energy Levels and Broad Absorption. Acc. Chem. Res. 2012, 45, 723-733.
(32) R. Zhang.; B. Li.; Iovu, M. C.; Jeffries-El, M.; Sauvé, G.; Cooper, J.; S. Jia.; Tristram-Nagle, S.; Smilgies, D. M.; Lambeth, D. N.; McCullough, R. D.; Kowalewski, T. Nanostructure Dependence of Field-Effect Mobility in Regioregular Poly(3-hexylthiophene) Thin Film Field Effect Transistors. J. Am. Chem. Soc. 2006, 128, 3480-3481.
(33) C. Liu.; K. Wang.; X. Hu.; Y. Yang.; C. H. Hsu.; W. Zhang.; S. Xiao.; X. Gong.; Y. Cao. Molecular Weight Effect on the Efficiency of Polymer Solar Cells. ACS Appl. Mater. Interfaces 2013, 5, 12163-12167.
(34) Najari, A.; Beaupré, S.; Berrouard, P.; Zou, Y.; Pouliot, J. R.; Lepage-Pérusse, C.; Leclerc, M. Synthesis and characterization of new thieno[3,4-c]pyrrole-4,6-dione derivatives for photovoltaic applications. Adv. Funct. Mater. 2011, 21, 718-728.
(35) Y. Fu.; H. Cha.; S. Song.; G. Y. Lee.; Eon Park, C.; Park, T. Low-bandgap quinoxaline-based D - A-type copolymers: Synthesis, characterization, and photovoltaic properties. J. Polym. Sci., Part A: Polym. Chem. 2013, 51, 372-382.
(36) K. Lu.; J. Fang.; H. Yan.; X. Zhu.; Y. Yi.; Z, Wei. A facile strategy to enhance absorption coefficient and photovoltaic performance of two-dimensional benzo[1,2-b:4,5-b′]dithiophene and thieno[3,4-c]pyrrole-4,6-dione polymers via subtle chemical structure variations. Org. Electron. 2013, 14, 2652-2661.
(37) Z. Ma.; D. Dang.; Z, Tang.; Gedefaw, D.; Bergqvist, J.; W. Zhu.; Mammo, W.; Andersson, M. R.; Inganäs, O.; Zhang, F.; E, Wang. A facile method to enhance photovoltaic performance of benzodithiophene- isoindigo polymers by inserting bithiophene spacer. Adv. Energy Mater. 2014, 4.
(38) Hae-Jung Son.; Wei, Wang.; Tao, Xu.; Yongye, Liang.; Yue, Wu.; Gang, Li.; Luping, Yu. Synthesis of Fluorinated Polythienothiophene-co-benzodithiophenes and Effect of Fluorination on the Photovoltaic Properties. J. Am. Chem. Soc. 2011, 133, 1885-1894.
(39) Youichi, Sakamoto.; Shingo, Komatsu.; Toshiyasu, Suzuki. Tetradecafluorosexi
thiophene: The First Perfluorinated Oligothiophene. J. Am. Chem. Soc. 2001, 123, 4643-4644.
(40) 林宏澤: 含苯並二噻吩單元之共軛高分子合成、分析及其在太陽能電池之應用. 國立台灣科技大學材料工程與科學研究所碩士論文, 2015.
(41) J. C. Chen.; H. C. Wu.; C. J. Chiang.; T. Chen.; L. Xing. Synthesis and properties of air-stable n-channel semiconductors based on MEH-PPV derivatives containing benzo[c]cinnoline moieties. J. Mater. Chem. C. 2014, 2, 4835-4846.
(42) Y, Yao.; H, Dong.; W, Hu. Ordering of conjugated polymer molecules: recent advances and perspectives. Polym. Chem. 2013, 4, 5197-5205.
(43) K, I.; S. K.; K. U.; A. O.; Reddy, S. L.; Endo, T. High Resolution X-Ray Diffraction Analyses of (La,Sr)MnO3/ZnO/Sapphire(0001) Double Heteroepitaxial Films. Adv. Phys. Org. Chem. 2013, 3, 72-89.