Photorefractive Cyclometalated Complexes

Some of the most recent results on the photoconducting and photorefractive properties of cyclometalated complexes are reviewed. Pure compounds show good photoconducting properties, which can be increased by orders of magnitude by doping with fullerenes. In addition, photorefractivity has been observed both in pure materials in their glassy state and in mixtures with inert polymers. In such mixtures, at high concentrations of complexes, dispersions of small (less than 200 nm) crystals of the complex within a polymeric matrix can be obtained. This morphology has been clearly linked to an increase in photorefractive performance, measured through diffraction efficiency, by onders of magnitude. Moreover; complexes with proper ligands exhibit chiral smectic mesophases with ferroelectric properties which also show photorefractive properties.