窄带隙聚合物光伏材料的合成及其表征

【作者】 刘波；

【导师】 潘春跃； 邹应萍；

【作者基本信息】 中南大学 ， 有机化学， 2010， 硕士

【摘要】 聚合物光伏材料的吸收光谱与载流子迁移率是影响聚合物太阳能能量转换效率的重要因素。本文以拓宽聚合物的吸收光谱和提高载流子迁移率为目的,设计与合成了一系列新型的共轭聚合物,主要开展的工作如下：(1)合成了一种侧链为空穴传输单元二苯胺乙烯基的聚噻吩衍生物(DPAV-PT)并对其进行了详细表征。研究结果表明该聚合物具有较宽的吸收光谱(300-650 nm),相对高的空穴迁移率(6.1×10-4cm2/Vs, FET法),在AM 1.5G,100 mW/cm2下的能量转换效率(PCE)为0.7%。(2)通过HECK偶联聚合,合成了两种新型的二噻吩苯并噻二唑类低能隙聚合物,对其进行了详细表征。结果显示：这类聚合物具有宽的吸收光谱(300-760 nm),电化学能隙在1.67-1.69 eV之间,基于PPV-DTBT的太阳能电池的PCE为0.6%。(3)首次将异靛(ID)受体单元引入聚合物光伏材料中,合成了三种窄带隙的聚合物。光学性能显示此类聚合物具有宽吸收,合适的HOMO与LOMO能级,初步器件结果表明此类聚合物是一类很有前景的光伏材料。更多还原

【Abstract】 The absorption spectra and hole mobility of conjugated polymer donor materials are the major factors to affect the power conversion efficiency (PCE) of polymer solar cells (PSCs). This dissertation is focusing on the design and synthesis of new conjugated polymers with broader absorption band and higher hole mobility for improving the photovoltaic properties of the conjugated polymers. The main results are as follows:(1) A new polythiophene derivative with octyl diphenylamine-vinylene conjugated side chain was synthesized by the Stille coupling reaction, and characterized by 1H NMR, GPC, TGA, UV-Vis absorption spectroscopy, and cyclic voltammetry. DPAV-PT possesses a broad absorption band at 300-650 nm. Polymer solar cell with the configuration of ITO/PEDOT:PSS/DPAV-PT:PCBM(1/1, w/w)/Ca/Al demonstrates the power conversion efficiency of 0.7% under the illumination of AM 1.5G,100 mW/cm2. The field effect hole mobility of the polymer reached 6.1×10-4 cm2/Vs with an on/off ratio of 103 and threshold voltage of-7 V after 180℃annealing.(2) Two new low bandgap black copolymers derived from dithienylbenzothiadiazole (DTBT) and different electron-rich functional groups (dioctoxyl benzene and N-octyl-diphenylamine) were synthesized by Heck cross-coupling polymerization. DSC and TGA results indicate that the copolymers possess good thermal stabilities. PPV-DTBT and DPAV-DTBT films exhibit broad absorption bands at 300-765 nm and 300-733 nm, respectively. Preliminary photovoltaic cells based on the composite structure of ITO/PEDOT:PSS/PPV-DTBT:PC60BM(1/2, w/w)/Al showed an open-circuit voltage of 0.75 V, a power conversion efficiency of 0.6% and a short circuit current of 1.7 mA/cm2.(3) A series of new isoindigo-based conjugated polymers were synthesized by Stille or Suzuki coupling reaction. The polymer films exhibit a broad absorption bands in the wavelength range from 300-800 nm. Especially, PBDTID possesses the smallest bandgap of 1.55 eV calculated from its absorption band-edge at 800 nm. These results show that isoindigo-based donor-acceptor copolymers are promising broad absorption and low bandgap materials for developing efficient bulk heterojunction solar cells.更多还原