Improved photovoltaic performance of a nonfullerene acceptor based on a benzo[<i>b</i>]thiophene fused end group with extended π-conjugation
作者:Kun Yang、Qiaogan Liao、Chang Woo Koh、Jianhua Chen、Mengyao Su、Xin Zhou、Yumin Tang、Yang Wang、Youming Zhang、Han Young Woo、Xugang Guo
DOI:10.1039/c9ta01111k
日期:——
A new indacenodithiophene-based acceptor–donor–acceptor (A–D–A) type nonfullerene acceptor material ITBTC, featuring a conjugation-extended benzo[b]thiophene-fused end group, was designed and synthesized. Compared to the well known phenyl-fused ITIC acceptor containing a 2-(3-oxo-2,3-dihydroinden-1-ylidene)malononitrile (IC) end group, incorporation of an additional electron-rich thiophene into the
设计并合成了一种新的基于茚并二噻吩基的受体-供体-受体(AD)类型的富勒烯受体材料ITBTC,其具有共轭扩展的苯并[ b ]噻吩稠合端基。与包含2-(3-oxo-2,3-dihydroinden-1-ydrene)malononitrile(IC)端基的众所周知的苯基融合ITIC受体相比,将额外的富电子噻吩并入IC部分可降低端基的电子接受强度,并增加了ITBTC分子的分子间相互作用。结果,ITBTC呈现出升高的最低未占据分子轨道,改善的电子迁移率和更有利的混合膜形态。尽管其吸收发生了蓝移,但由于在短波长范围内有额外的吸收带(由其共轭扩展末端基团诱导),因此基于ITBTC的设备的光电流得以很好地保持。受益于这些特性,基于ITBTC的太阳能电池的功率转换效率(PCE)达到了10.99%,同时开路电压(V oc,0.94 V)和填充系数(FF,71.3%)也得到了改善。与之相比,保持的短路电流密度(J