Dynamic holographic images using polyvinylcarbazole-based photorefractive composites

We present here the optimized photorefractive polymeric composite (PPC) film based on simple materials of poly(N-vinylcarbazole) (PVCz)/4-azacycloheptylbenzylidenemalononitrile (7-DCST)/N-ethylcarbazole (ECz)/2,4,7-trinitro-9- fluorenone (TNF). The-simple-materials-based PPC was optimized from the photorefractive characteristics of PPCs with PVCz/7-DCST/ECz/TNF (the best ratio: 44/35/20/1 wt %) that changed molecular weights of PVCz: 23,000, 100,000, 290,000, 370,000, 520,000, 780,000, 860,000, and < 1,000,000 g mol-1. Diffraction efficiency and photorefractive response time of the PPC film with Mw: 860,000 of PVCz/7-DCST/ECz/TNF (44/35/20/1 wt %) showed an appropriate photorefractive performance, which was determined as the optimized PPC. It is notable that the optimized PPC could be easily obtained from relatively inexpensive materials; furthermore, the required nonlinear optical dye 7-DCST could be synthesized in high-yield. We believe that the PPCs based on PVCz or other polyvinylcarbazole derivatives will be the potential composite for creating holographic displays because of low fabrication costs, and be of benefit to developing technologies.