Design of Fullerene-Free Electron-Acceptor Materials Containing Perylenediimide Units for Solution-Processed Organic Electronic Devices

Organic electron-accepting materials with light absorbance and wide absorption bands are sorely needed as alternatives to fullerene derivatives for organic electronics, in particular for organic photovoltaic (OPV) applications. In the present study, we have designed and synthesized a series of novel donor-acceptor-donor (D-A-D) electron-accepting molecules based on perylenediimide (PDI) and oligothiophene units, that is, PDI-alkoxy, PDI-Th, PDI-BiTh, and PDI-TerTh. The optical and electrochemical properties of the obtained PDI derivatives and performances of organic field-effect transistor (OFET) and OPV devices based on PDI derivatives were investigated. The PDI derivatives showed a higher light absorption intensity and wider absorption region than those of [6,6]-phenyl-C-61-butyric acid methyl ester (PC61BM). The highest electron mobility (2.33 x 10(-4) cm(2) V-1 s(-1)) was shown using an OFET device based on PDI-BiTh, and the highest power conversion efficiency (PCE) of 5.2 x 10(-2)% was given by the OPV device based on the PDI-BiTh acceptor. The device performances demonstrated that PDI derivatives with a D-A-D architecture are potentially useful for solution-processed organic electronics.