Tuning the optoelectronic properties of vinylene linked perylenediimide dimer by ring annulation at the inside or outside bay positions for fullerene-free organic solar cells  

作　　者：Jing Yang Fan Chen Peiqing Cong Hongjun Xiao Yanfang Geng Zhihui Liao Lie Chen Bao Zhang Erjun Zhou 

机构地区：[1]CAS Key Laboratory of Nanosystem and Hierarchical Fabrication,CAS Center for Excellence in Nanoscience,National Center for Nanoscience and Technology,Beijing 100190,China [2]Center of Materials Science and Optoelectronics Engineering,University of Chinese Academy of Sciences,Beijing 100049,China [3]College of Chemistry,Nanchang University,999 Xuefu Avenue,Nanchang 330031,Jiangxi,China [4]Henan Institutes of Advanced Technology,Zhengzhou University,97 Wenhua Road,Zhengzhou 450003,Henan,China

出　　处：《Journal of Energy Chemistry》2020年第1期112-119,I0005,共9页能源化学（英文版）

基　　金：supported by the National Key Research and Development Program of China (2017YFA0206600);the Key Research Program of Frontier Sciences, Chinese Academy of Sciences (Grant No. QYZDB-SSW-SLH033);the National Natural Science Foundation of China (NSFC, Nos. 51473040, 51673048, 21875052, 51673092)

摘　　要：Among various perylenediimide(PDI)-based small molecular non-fullerene acceptors(NFAs),PDI dimer can effectively avoid the excessive aggregation of single PDI and improve the photovoltaic performance.However,the twist of perylene core in PDI dimer will destroy the effective conjugation.Thus,ring annulation of PDI dimer is a feasible method to balance the film quality and electron transport,but the systematic study has attracted few attentions.Herein,we choose a simple vinylene linked PDI dimer,V-PDI2,and then conduct further studies on the structure-property-performance relationship of four kinds of derived fused-PDI dimers,namely V-TDI2,V-FDI2,V-PDIS2 and V-PDISe2 respectively.The former two are incorporated thianaphthene and benzofuran at the inside bay positions,and the latter two are fused thiophene and selenophene at the outside bay positions,respectively.Theoretical calculations reveal the inside-and outside-fused structures largely affect the skeleton configuration,the former two tend to be planar structure and the latter two maintain the distorted backbone.The photovoltaic characterizations show that the inside-fused PDI dimers offer high open circuit voltage(VOC),while the outside-fused PDI dimers afford large short-circuit current density(JSC).This variation tendency results from the reasonably tunable energy levels,light absorption,molecular crystallinity and film morphology.As a result,PBDB-T:V-PDISe2 device exhibits the highest power conversion efficiency(PCE)of 6.51%,and PBDB-T:VFDI2 device realizes the highest VOC of 1.00 V.This contribution indicates that annulation of PDI dimers in outside or inside bay regions is a feasible method to modulate the properties of PDI-based non-fullerene acceptors.Among various perylenediimide（PDI）-based small molecular non-fullerene acceptors（NFAs）, PDI dimer can effectively avoid the excessive aggregation of single PDI and improve the photovoltaic performance.However, the twist of perylene core in PDI dimer will destroy the effective conjugation. Thus, ring annulation of PDI dimer is a feasible method to balance the film quality and electron transport, but the systematic study has attracted few attentions. Herein, we choose a simple vinylene linked PDI dimer,V-PDI2, and then conduct further studies on the structure-property-performance relationship of four kinds of derived fused-PDI dimers, namely V-TDI2, V-FDI2, V-PDIS2 and V-PDISe2 respectively. The former two are incorporated thianaphthene and benzofuran at the inside bay positions, and the latter two are fused thiophene and selenophene at the outside bay positions, respectively. Theoretical calculations reveal the inside-and outside-fused structures largely affect the skeleton configuration, the former two tend to be planar structure and the latter two maintain the distorted backbone. The photovoltaic characterizations show that the inside-fused PDI dimers offer high open circuit voltage(VOC), while the outside-fused PDI dimers afford large short-circuit current density(JSC). This variation tendency results from the reasonably tunable energy levels, light absorption, molecular crystallinity and film morphology. As a result,PBDB-T:V-PDISe2 device exhibits the highest power conversion efficiency（PCE） of 6.51%, and PBDB-T:VFDI2 device realizes the highest VOC of 1.00 V. This contribution indicates that annulation of PDI dimers in outside or inside bay regions is a feasible method to modulate the properties of PDI-based non-fullerene acceptors.

关 键 词：PERYLENEDIIMIDE Vinylene Inside-fused Outside-fuse Fullerene-free solar cell 

分 类 号：TB383.2[一般工业技术—材料科学与工程] TM914.4[电气工程—电力电子与电力传动]