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).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，5 H) -dione} ( pDPPTTZ-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，5 H) -dione} ( pDPPTTZ-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，5 H) -
dione} ( pDPPTTZ-Py) ． These polymers exhibit deep HOMO energy levels ( － 5． 26 ～ － 5． 37 eV) ， 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 around
620 nm and optical band gap of 1． 86 ，1． 83 and 1． 85 eV for pDPPTTZ-T，pDPPTTZ-Se and pDPPTTZ-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 pDPPTTZ-T∶ PCBM-based device without
optimization，under simulated AM 1． 5 G irradiation of 100 mW/cm2 ．国家自然科学基金(基金号21367004);广西高校人才小高地建设创新团队项目(项目号GJR201147-12)资
