Novel unsymmetrically hyperbranched polythiophenes with conjugation gradient

Novel hyperbranched polythiophenes containing unsymmetrically substituted thiophene units have been synthesized. These materials are designed to have conjugation gradient in their structure and be capable of light harvesting. Study of their optical properties shows a broad-band absorption, strong fluorescence, and an effective intramolecular energy transfer. They are potentially useful for the preparation of efficient photovoltaic as well as light-emitting devices. (C) 2002 Elsevier Science Ltd. All rights reserved.