A push-pull organic semiconductor with efficient intramolecular charge transfer for solution-processed small molecule solar cells

Abstract

A new push-pull organic semiconductor, DMF-BP-T-MMN, containing a functionalized amine donor and a methylene malononitrile (MMN) acceptor has been designed and synthesized for use in solutionprocessable small molecule solar cells. This material exhibits superior intramolecular charge transfer from the functionalized amine group to MMN, which produces an electron-rich MMN group that facilitates electron transfer into the active layer constituent phenyl-C-71-butyric acid methyl ester in a solar cell. As a result, DMF-BP-T-MMN was found to exhibit excellent p-type semiconductor performance in an optimized organic solar cell: a power conversion efficiency of 3.40% with a high photocurrent density of 8.2 mA cm (2).