Synthesis of a new W-type of functional polymer for improving intermolecular charge transfer processes at donor/acceptor interfaces

Abstract

Optimizing charge transfer (CT) processes at donor/acceptor interfaces is an important subject to improving photocurrent density. Geometries of functional polymers play important roles in design of new types of polymers, which were used as electron donor to improve effective separation of electron-hole pairs at donor/acceptor interfaces. In this article, a novel W-type of polymer, poly(1-[4-(9-(2-ethylhexyl)carbazole-3-yl)]phenylazo-2-phenylazoacenaphthylene), was synthesized by a Suzuki coupling reaction for improving interaction between polymers and electron acceptors to enhance intermolecular CT. Geometry of combination of the polymer and C60 shows that main-chain of the polymer could sufficiently touch C60 derivatives. The polymer exhibited a broadband light absorption at the wavelength range from 250 to 650 nm. Ultraviolet–visible spectra and cyclic voltammetry curve suggest that the highest occupied, lowest unoccupied molecular orbital energy levels, and energy gap values are −5.09, −3.18 and 1.91 eV. Fluorescence quenching experiments shows that 99.9% of emission fluorescence of the polymer was quenched by added C60. Therefore, excited electrons at the polymer would be completely transferred to C60 molecules. This article suggests a new W-type functional polymer for improving intermolecular CT processes at donor/acceptor interfaces.