摘要
高分子光伏材料聚对苯撑乙烯撑(PPV)由于低廉的价格,容易加工的性能与可调的光学性能,有可能成为新一代太阳能材料.然而PPV较宽的带隙阻碍了PPV太阳能电池效率进一步提高.合成了一种较低带隙的新型高分子光伏材料PPV-PQ.用NMR,FT-IR,元素分析,GPC和TGA与循环伏安法对PPV-PQ进行了结构表征与性能检测,并对它在氯仿溶液与固态薄膜下的紫外-可见吸收与荧光发射光谱进行了研究.结果显示,由于在固态下存在较强的分子间作用,分子链的共平面性增加,所以PPV-PQ无论是紫外-可见吸收,还是荧光发射光谱,在固态薄膜下都比在氯仿溶液里发生明显红移.即使在浓溶液中,分子链间也存在较强的作用力,使得PPV-PQ荧光发射峰随溶液浓度的增加而发生红移.紫外-可见光谱显示,PPV-PQ由于大体积的吸电子单元引起了较大的空间位阻,最大吸收峰比PPV稍微蓝移,但吸收却比PPV向长波延展,带隙比PPV低,只有1.92 eV.循环伏安法结果表明PPV-PQ与PCBM两者的LUMO之间有足够的能量差异,加上PPV-PQ与富勒烯衍生物C_(117)共混物薄膜发生荧光猝灭,都说明PPV-PQ上光激发电子能够转移到富勒烯衍生物上.因此,PPV-PO可以用作高分子光伏材料.
A novel poly（phenylenevinylene） copolymer PPV-PQ containing alternating phenyl rings and quinoxaline units has been synthesized and characterized by NMR, FT-IR, TGA, GPC, TGA and elemental analysis. The UV-Vis absorption spectra and PL spectra in solution/films were characterized. The absorption peak and PL emission peak of PPV-PQ in the solid state, were shift to long wavelengths compared to their corresponding peaks in solution due to strong inter-chain interactions and increased coplanarity. The PPV-PQ exhibited a decreased optical band gap （1.92 eV） compared to PPV homopolymer. The HOMO and LUMO .levels of PPV-P.Q were determined from electrochemical measurements. There is a clear difference between LUMO （--3.16 eV） of polymer and that of PCBM, which makes an effective charge transfer possible between polymers and PCBM. The PL emission intensity of PPV-PQ is almost completely quenched when PPV-PQ is blended with C117. The result shows that PPV-PQ is useful for polymer solar cells.
出处
《化学学报》
SCIE
CAS
CSCD
北大核心
2009年第21期2475-2480,共6页
Acta Chimica Sinica
基金
西北工业大学基础研究基金(No.w018102)资助项目
关键词
高分子
光伏材料
聚对苯撑乙烯撑
polymer
photovoltaic material
poly（phenylenevinylene）
