Photoconductive and photorefractive organic-inorganic hybrid polymeric composites containing semiconductor nanocrystals.

摘要

The use of inorganic semiconductor nanocrystals is shown to be an effective photosensitizer in polymeric photoconductive and photorefractive materials. The ability to tune the spectral properties of the nanocrystals is demonstrated, as is the ability to achieve charge-generation quantum efficiencies in excess of those observed in similar composites photosensitized with traditional organic dyes. Next, the ability to extend the photosensitivity of polymeric photorefractive composites into the infrared portion of the spectrum, well beyond the range reported for any organic dye is demonstrated. This is achieved through the use of narrow-band gap semiconductor nanocrystals. Finally the ability to combine the approach of nanocrystal photosensitization with other techniques with similar goals is demonstrated. Here, a polymer dispersed liquid crystal composite was fabricated with the inclusion of inorganic nanocrystals serving as photosensitizers. In this instance, superior photorefractive behavior, over any other previously reported for a polymer dispersed liquid crystal composite, was demonstrated. Thus, a novel and effective means by which to photosensitize polymeric composites has been established.