Monodispersed vs. polydispersed systems for bulk heterojunction solar cells: the case of dithienopyrrole/anthracene based materials
作者:Roberto Grisorio、Giovanni Allegretta、Gian Paolo Suranna、Piero Mastrorilli、Anna Loiudice、Aurora Rizzo、Marco Mazzeo、Giuseppe Gigli
DOI:10.1039/c2jm33795a
日期:——
The article reports on the properties of a new class of arylene–ethynylene semiconductors incorporating anthracene and the bridged bithiophene dithienopyrrole. Two monodispersed structures were synthesised: the first with a dithienopyrrole core bound to two anthracenyl–ethynyl side groups namely the 2,6-bis(anthracen-9-ylethynyl)-4-(2-ethylhexyl)-4H-dithieno[3,2-b:2′,3′-d]pyrrole (ADA); in the second structure the anthracene core was functionalised with two dithienopyrrolylethynyl groups, obtaining 9,10-bis((4-(2-ethylhexyl)-4H-dithieno[3,2-b:2′,3′-d]pyrrol-2-yl)ethynyl)anthracene (DAD). The properties of these materials were compared with those of the corresponding polymer: poly[4-(2-ethylhexyl)-4H-dithieno[3,2-b:2′,3′-d]pyrrole-2,6-diylethynylene-anthracen-9,10-diylethynylene] (polyAD). Devices employing PC61BM as an electron acceptor revealed that the monodispersed materials (ADA and DAD) were better performing than polyAD, seemingly due to the better homogeneity of the donor–acceptor blend, as revealed by AFM. The PCE value (1.3%) obtained with DAD ranks among the highest reported for non-polymeric small molecule-based BHJ solar cells constructed without the use of additives or annealing processes, thus demonstrating that ethynylene-containing electron-rich systems are promising donors for organic solar cell applications.
文章报道了一类新型苯亚乙炔半导体,包含蒽和桥连双噻吩二噻吩并吡咯。合成了两种单分散结构:第一种以二噻吩并吡咯为核心,结合两个蒽基乙炔侧基,即2,6-双(蒽-9-基乙炔基)-4-(2-乙基己基)-4H-二噻吩[3,2-b:2′,3′-d]吡咯(ADA);在第二种结构中,蒽核心功能化,结合两个二噻吩并吡咯乙炔基,得到9,10-双((4-(2-乙基己基)-4H-二噻吩[3,2-b:2′,3′-d]吡咯-2-基)乙炔基)蒽(DAD)。这些材料的性能与相应的聚合物:聚[4-(2-乙基己基)-4H-二噻吩[3,2-b:2′,3′-d]吡咯-2,6-二乙炔基-蒽-9,10-二乙炔基](polyAD)进行了比较。采用PC61BM作为电子受体的器件表明,单分散材料(ADA和DAD)的性能优于polyAD,这似乎是由于供体-受体混合物的均匀性更好,如AFM所示。DAD得到的PCE值(1.3%)是未使用添加剂或退火工艺构建的非聚合物小分子基BHJ太阳能电池中报道的最高值之一,这表明含有乙炔的富电子系统是Organic solar cell applications有前途的供体。