Preparation And Properties Of Organic-inorganic Nanoparticles Hybrid Photorefractive Material

A great amount of attention has been paid to the development of organic-inorganic composite photorefractive (PR) materials for their potential applications in optical information memory and processing. Nanocomposites consisting of inorganic nanoparticles and organic polymers often exhibit a host of mechanical, electrical, optical and magnetic properties, which are far superior compared with those of the individual components. So organic-inorganic nanocomposite photorefractive materials are promised to change the charge transport mechanism and make a breakthrough in the improvement of pohtorefractivity. In this paper, we have investigated the development of organic-inorganic composite PR material, prepared a new organic-inorganic nanocomposite PR material of PVK-CdS/DMNPAT, characterized every component and tested it photorefractivty by two beam coupling experiment.The work of this paper includes mainly three parts as followed:(1) An azo dye DMNPP was prepared via reoxidation and coincidence reaction and its derivative DMNPAT was prepared by attaching a long methacrylate chain in DMNPP. The structure of tow dyes, the glass-transition-temperature (T_g) of their according PR materials and the properties change after corona-onset poling were characterized and tested in the experiment. The fusing point of DMNPP is 173℃ and the T_g of the according PR sample is 75℃. The fusing point of DMNPAT is 83℃ and its PR sample's T_g is 29℃. We can polarize the PR sample with DMNPAT in room temperature. Not any obvious change of the content of DMNPAT was observed after corona-onset poling.(2) A two-components nanocomposite of CdS-PVK was prepared by direct chemical hybridization. The CdS nanoparticles with a particle diameter of 15~25nm were dispersed in the polymer equably. We compared the properties of the CdS-PVK nanocomposites prepared by chemical hybridization and traditional physical dropping. The nanocomposite prepared by chemical hybridization improves the mechanical properties successfully and makes the charge carrier transport through the interface between PVK and CdS nanoparticles. This interface charge transport can hinder theexcitons recombination; enhance the concentration and life time of the excitons and increase the generation speed and electric field intensity of the internal space electric field to improve the final photorefractiviy.(3) A PR sample of PVK-CdS/DMNPAT was designed and prepared for tow beam coupling experiment. In this experiment, energy transferring from one beam to another one successfully and a two-beam coupling (TBC) coefficient of 86.24 cm-1 was obtained without any electric field.