Photoinduced energy transfer and charge transfer on squarylium cyanine dyes

Abstract

AbstractA series of squarylium cyanine dyes (Sqs) were synthesised to explore their applications in functional devices. Preliminary investigation on the mechanism involved in these devices was carried out. Spectroscopic behavior of Sqs with porphyrin (P), 8‐hydroxyquinolium aluminum (Alq) and ruthenium bipyridyl complex (Ru(bipy)) in solution, in film and on nanocrystalline TiO2 was investigated, respectively. A mechanism including photoinduced energy transfer and charge transfer processes was suggested in the corresponding practical devices. By means of doping, a red organic electroluminescent device (ELD) using Sq‐doped Alq as the emission layer (EML) has been developed, and the total light to electricity efficiency of nanocrystalline TiO2 electrode based on using Sq‐doped Ru(bipy) M photosensitizer has been improved greatly in the whole visible region, particularly in the red area above 600 nm.