New Photorefractive Polymers Exhibiting Enhanced Performances

摘要

By utilizing both the Heck and Wittig reaction, an orthogonal approach was developed towards the stepwise synthesis of end-functionalized oligo-phenylenevinylenes. A significant advantage of this approach is that no protecting group chemistry is involved and this approach can be further utilized to synthesize dendritic molecules with PPV structures. The funtionalized OPVs can be further coupled with other functional polymers to form diblock copolymers. These OPV exhibit liquid crystallinity and luminescent properties. Recently, a new photorefractive polymer which contains an ionic tri(bispyridyl) ruthenium complex as the charge generation species, a conjugated polymer backbone as the charge transporting channel and a nonlinear optical chromophore was designed and synthesized. These polymers designed to address numerous issues still unresolved in photorefractive polymer systems. A crucial one is associated with the photoconducting process, that is, both the low quantum yield of the photogeneration of charge carriers and the low mobility of the charge carriers. The ruthenium complex was introduced to utilize its efficient light induced metal-to-ligand charge transfer process. This polymer shows greatly enhanced photorefractive performance; a large net optical gain of about 300/cm was obtained at a zero external electric field.