二噻并苯并二噻吩基有机太阳能电池给体材料的研究进展

Research Progress on Dithieno [2,3-d:2',3'-d']benzo [1,2-b:4,5-b'] dithiophene-based Donor Materials for Organic Solar Cells

有机太阳能电池(OSCs)因制备过程简单、质量轻、成本低廉和可制成柔性器件而备受学术界和产业界的青睐。增大重复单元的共轭面和共轭长度可明显增大π重叠、提高π-π堆积改善电荷迁移率,还可降低共轭体系重组能以利于光生激子拆分为自由电荷。相比苯并[1,2-b:4,5-b']二噻吩(BDT),二噻并[2,3-d:2',3'-d']苯并[1,2-b:4,5-b']二噻吩(DTBDT)具有更大共轭面和共轭长度,且有与BDT相似的最高分子占据轨道(HOMO)能级,给电子能力相近。二维的DTBDT共聚物和小分子材料相比一维的表现出优异的光伏性能,尤其是宽带隙共聚物PDBT-T1与改进的"合金"富勒烯或非富勒烯受体的效果显著。基于DTBDT优异的光伏特性和本课题组近年的研究工作,在此对含DTBDT单元的光伏给体材料的研究进展进行综述。

Organic solar cells（ OSCs） have attracted more and more attention in both academic and industrial fields,owing to their excellent advantages of easy fabrication,light- weight,low- cost and flexibility. The enhanced conjugated plane and the expanded conjugation length in the repeat unit not only enlarge the overlapping to enhance the π- πstacking and,thus improve the charge mobility,but also reduce the reorganization energy in the moieties and facilitate the exciton separation into the free charge carriers. Compared to the star molecule benzo[1,2- b： 4,5- b＇]dithiophene（ BDT）,dithieno[2,3- d： 2＇,3＇- d＇]benzo[1,2- b： 4,5- b＇]dithiophene（ DTBDT） possessed a much larger conjugated plane and extended conjugated length,as well as a similar of the highest occupied molecular orbital（ HOMO）energy level and electron- donating ability. Compared with one- dimensional（ 1D） DTBDT- based conjugated polymers and small molecules,two- dimensional DTBDT- based materials exhibited more excellent photovoltaic performance. And the performance based on wide bandgap polymer PDBT- T1 and ＂alloy acceptor ＂mixed acceptor or non- fullerene acceptors was particularly outstanding. On the basis of the excellent photovoltaic performance and our main research work in recent years,the progress of photovoltaic donor materials related to DTBDT was reviewed in detail.