A Novel Alternating Phenylenevinylene Copolymer with Perylene Bisimide Units: Synthesis, Photophysical, Electrochemical, and Photovoltaic Properties

Abstract

An alternating phenylenevinylene copolymer P bearing perylene bisimide moieties along the backbone was synthesized by Heck coupling. The tert-butyl and hexyloxy side groups enhanced the solubility of the copolymer in common organic solvents. It had glass transition and decomposition temperatures of 72 and 370 °C, respectively. The absorption of P was broad, with longer wavelength maximum around 500 nm and optical band gap of 1.66 eV. The solution of P emitted yellow−orange light with photoluminescence (PL) maximum at 555 nm. Moreover, efficient interaction and charge/energy transfer between the phenylenevinylene−donor and the perylene bisimide−acceptor led to PL quenching in the thin film of P. The current−voltage characteristics of ITO/copolymer P/Al indicated that copolymer P behaved as an n type organic semiconductor. The electron current was found to be a space charge limited current (SCLC), providing a direct measure of mobility as a function of temperature and field. The average electron mobility fo...