Large Two-Beam Coupling in the p-PMEH-PPV/DPP/DO3/C60

Abstract

Since the photorefractive (PR) effect is based on the photoinduced buildup of a space-charge field in an electro-optic material, the photogeneration of charge carrier and their subsequent migration by diffusion or drift in an electric field play a key role in determining the magnitude and speed of PR response. To enhance the photoconductivity, we used a π-conjugated polymer, poly[o(p)-phenylenevinylene-alt-2-methoxy-5-(2-ethylhexyloxy)-p-phenylenevinylene] (p-PMEH-PPV), as a charge transport polymer matrix and C60 as a photosensitizer in this study. The photorefractive response time decreased with the increase of photosensitizer amount. Furthermore, large two-beam coupling gain coefficient was obtained, above 400 cm-1, in the case of PPVC1.