title: N-acyldithieno[3,2-b:2',3'-d]pyrrole-based low-band-gap conjugated polymer solar cells with amine-modified [6,6]-phenyl-C61-butyric acid ester cathode interlayers.
abstract: Efficient low-band-gap polymers are one key component for constructing tandem solar cells with other higher-band-gap materials to harvest wide absorption of the solar spectrum. The N-acyldithieno[3,2-b:2',3'-d]pyrrole (DTP) building block is used for making low-band-gap polymers. It is attractive because of its strong donating ability and relatively low highest-occupied-molecular-orbital level in comparison with the N-alkyl DTP building block. However, additional solubilizing groups on the accepting units are needed for soluble donor-acceptor polymers based on the N-alkanoyl DTP building block. Combining N-benzoyl DTP with a 4,7-dithieno-2,1,3-benzothiadiazole building block, a polymer with a low band gap of 1.44 eV, delivers a high short-circuit current of 17.1 mA/cm(2) and a power conversion efficiency of 3.95%, which are the highest for the devices with DTP-containing materials. Herein, an alcohol-soluble diamine-modified fullerene cathode interfacial layer improved the device efficiency significantly more than the mono-amine analogue.
authors.affiliation: Department of Chemistry, Zhejiang University , Hangzhou 310027, China.
authors.forename: Deng
authors.initials: D
authors.lastname: Hong
authors.forename: Menglan
authors.initials: M
authors.lastname: Lv
authors.forename: Ming
authors.initials: M
authors.lastname: Lei
authors.forename: Yu
authors.initials: Y
authors.lastname: Chen
authors.forename: Ping
authors.initials: P
authors.lastname: Lu
authors.forename: Yanguang
authors.initials: Y
authors.lastname: Wang
authors.forename: Jin
authors.initials: J
authors.lastname: Zhu
authors.forename: Haiqiao
authors.initials: H
authors.lastname: Wang
authors.forename: Mei
authors.initials: M
authors.lastname: Gao
authors.forename: Scott E
authors.initials: SE
authors.lastname: Watkins
authors.forename: Xiwen
authors.initials: X
authors.lastname: Chen