Novel soluble fluorene-thienothiadiazole and fluorene-carbazole copolymers for optoelectronics

摘要

Optical, photophysical, electrochemical and photoelectrical properties of novel soluble low-bandgap fluorene - thienothiadiazole based copolymers (CHTF and CDTF) and luminescent fluorene - carbazole copolymers, (CFCzE and CFCZA) were studied. Fluorene - thienothiadiazole copolymers exhibit in thin films long-wavelength absorption with maxima at 750 - 785 nm and possess low bandgap, high electron affinity and exhibit reversible electrochromic behaviour. Therefore they are of interest for electrochromic and photovoltaic applications. Spectroelectrochemical study was performed and optical switching was demonstrated. Photovoltaic devices with bulk heterojunction made of blends of copolymers and fullerene derivative [60]PCBM were prepared. The power conversion efficiency was 2-3%. On the other hand, the fluorene-carbazole copolymers exhibit blue photoluminescence with high quantum efficiency in solution and also in thin films. Light-emitting devices with intensive broad bluish-green-white emission were fabricated.