非富勒烯聚合物太阳电池研究进展

Recent Research Progress of Photovoltaic Materials for Nonfullerene Polymer Solar Cells

综述了以p-型共轭聚合物为给体、n-型有机半导体为受体的非富勒烯聚合物太阳电池光伏材料最新研究进展,包括n-型共轭聚合物和可溶液加工小分子n-型有机半导体(n-OS)受体光伏材料,以及与之匹配的p-型共轭聚合物给体光伏材料.介绍的n-型共轭聚合物受体光伏材料包括基于苝酰亚胺(BDI)、萘酰亚胺(NDI)以及新型硼氮键连受体单元的D-A共聚物受体光伏材料,目前基于聚合物给体(J51)和聚合物受体(N2200)的全聚合物太阳电池的能量转换效率最高达到8.26%.n-OS小分子受体光伏材料包括基于BDI和NDI单元的有机分子、基于稠环中心给体单元的A-D-A型窄带隙有机小分子受体材料等.给体光伏材料包括基于齐聚噻吩和苯并二噻吩(BDT)给体单元的D-A共聚物,重点介绍与窄带隙A-D-A结构小分子受体吸收互补的、基于噻吩取代BDT单元的中间带隙二维共轭聚合物给体光伏材料.使用中间带隙的p-型共轭聚合物为给体、窄带隙A-D-A结构有机小分子为受体的非富勒烯聚合物太阳电池能量转换效率已经突破12%,展示了光明的前景.最后对非富勒烯聚合物太阳电池将来的发展进行了展望.

Nonfullerene polymer solar cells （PSCs） based on p-type conjugated polymer as donor and n-typeorganic semiconductor （n-OS） as acceptor have attracted great attention in recent years, due to the advantages ofthe n-OS acceptors, such as strong and broad absorption in visible-NIR region, easy tuning of absorption andelectronic energy levels, and good morphology stability in comparison with the traditional fullerene derivativeacceptors. This article reviews the recent research progress of the n-OS acceptors （including n-type conjugatedpolymers and n-OS solution-processable organic small molecules） and the conjugated polymer donor photovoltaicmaterials for the application in nonfullerene PSCs. The n-type conjugated polymer acceptor materials include theperylene diimide （PDI）- and naphthalene diimide （NDI）-based D-A copolymers, as well as the D-A copolymersbased on the new B--N bonded acceptor unit. The highest power conversion efficiency （PCE） reached 8.24% forthe all polymer PSCs with a medium bandgap p-type conjugated polymer J51 as donor and a narrow bandgapn-type NDI-based D-A copolymer N2200 as acceptor. The n-OS small molecules acceptors include the PDI- orNDI-hased molecules, the narrow bandgap A-D-A structured small molecules with a fused ring central donor unitand two electron-withdrawing end groups （such as ITIC）, and other n-OS small molecules. The p-type conjugatedpolymer donor materials, matching with the nonfullerene acceptors, include the narrow bandgap oligothiophene-or banzodithiophene （BDT）-based copolymers, and the medium bandgap two-dimension-conjugated D-Acopolymers based on BDT with thiophene conjugated side chains. The best nonfellerene PSCs, with a mediumbandgap polymer as donor and a narrow bandgap A-D-A structured n-OS as acceptor, have been recentlydemonstrated to have high PCE of over 12%. The complementary absorption in the visible-NIR region, matchingelectronic energy levels of the donor and acceptor materials, is very important for the high performancenonfullerene PSCs. In the end of the article, we give some comments and point out the key issues for the next-stepstudies and future development of the nonfullerene PSCs.