Enhanced photorefractivity in a polymer/nanocrystal composite photorefractive device at telecommunication wavelength

Enhanced photorefractive (PR) response in nanocrystal-polymer nanocomposite PR devices at the telecommunication wavelength of 1.3 μm is achieved using facile surface treatment of PbS nanocrystals functionalized with thermally cleavable ligands. The cleavage of the ligands, by heat treatment, results in significant improvement in both photocharge generation and PR response, as demonstrated by photoconductivity and two-beam coupling (TBC) experiments, respectively. The TBC experiment shows that the optical gain coefficient is improved drastically (about 63%) at an applied electric field of 84 V/μm.