【摘要】 设计并合成了一种交叉共轭的(cross-conjugated)缺电子型聚合物单体——二溴代噻吩[2,3-b]并噻吩-吡咯[3,4-c]并吡咯(DPPTTZ)二酮,并将其分别与噻吩(T)、硒吩(Se)和N-甲基吡咯(Py)的双锡试剂进行共聚反应,获得了一类新的供体-受体(D-A)型共轭聚合物光电材料.这类材料分子的最高占有轨道(HOMO)能级较低,因此其光电器件具有较高的开路电压(Voc),稳定性好.此外,它们在紫外-可见光区有较宽的吸收,最大吸收位于波长620 nm附近;能带隙(band gap)小,分别为1.86 e V(p DPPTTZ-T)、1.83 e V(p DPPTTZ-Se)和1.85 e V(p DPPTTZ-Py).器件初步测试结果表明,上述聚合物与PC71BM组成的本体异质结聚合物太阳能电池Voc在0.68~0.81 V之间,能量转化效率(PCE)最高达3.05%(p DPPTTZ-T).更多还原

【Abstract】 Thieno [2,3-b]thiophene-diketopyrrolopyrrole(DPPTTZ),a novel cross-conjugated electrondeficient unit,has been synthesized.This unit was brominated and then copolymerized with 2,5-bis(trimethylstannyl) thiophene,2,5-bis(trimethylstannyl) selenophene and 2,5-bis(trimethyl-stannyl)-Nmethylpyrrole respectively,via Stille polymerzation,to form three donor-acceptor(D-A) type copolymers,poly{ 2,5-bis(2-octyldodecyl)-3-[5-(thiophen-2,5-yl) thieno[2,3-b]thiophen-2-yl]-6-(thieno[2,3-b]thiophen-2,5-yl) pyrrolo[3,4-c]pyrrole-1,4(2H,5H)-dione}(p DPPTTZ-T),poly{ 2,5-bis(2-octyldodecyl)-3-[5-(selenophen-2,5-yl) thieno[2,3-b]thiophen-2-yl]-6-(thieno[2,3-b]thiophen-2,5-yl) pyrrolo[3,4-c]pyrrole-1,4(2H,5H)-dione}(p DPPTTZ-Se) and poly{ 2,5-bis(2-octyldodecyl)-3-[5-(N-methylpyrrole-2,5-yl) thieno[2,3-b]thiophen-2-yl]-6-(thieno[2,3-b]thiophen-2,5-yl) pyrrolo[3,4-c]pyrrole-1,4(2H,5H)-dione}(p DPPTTZ-Py).These polymers exhibit deep HOMO energy levels(-5.26 ~-5.37 e V),leading to high open-circuit voltage(0.68 ~ 0.81 V) in OPV devices,and good stability of the devices towards atmospheric oxygen.The UV-Vis spectra show broad features with long-wavelength absorption maximum around620 nm and optical band gap of 1.86,1.83 and 1.85 e V for p DPPTTZ-T,p DPPTTZ-Se and p DPPTTZ-Py respectively,which give polymers a good overlap of solar spectrum.Bulk heterojunction solar cells were fabricated by blending these polymers with [6,6]-phenyl-C71-butiric acid methyl ester(PC71MB),and the power conversion efficiency(PCE) reaches 3.05% for the as cast p DPPTTZ-T∶ PCBM-based device without optimization,under simulated AM 1.5 G irradiation of 100 m W / cm2.更多还原