Preparation Of A New Photorefractive Polymer And Study On The Characterization Of Carrier Trap

Photorefractive effect is a very meaningful nonlinear optic (NLO) phenomenon. Because of its potential application in optics amplification, high density data storing, phase conjugation, hologram image processing etc photo-refraction has been paid lot of attention as soon as its discovery in 1967. As the polymer photorefractive effect was first observed, it immediately aroused people's great interest. Comparing with inorganic crystal, polymer photo-refraction has its own characteristics. In polymer photo-induced carrier quanta efficiency and charge transfer are dependent on applied electric field. But in the inorganic crystal this is not the case. Polymer photo-fraction materials have obvious advantages in research too, such as greater NLO coefficient, high optical damage threshold, and low dielectric constant, easily to be formed into many kinds of films and low cost etc. so the research of this subject has got great development at full speed. In the past years many brand-new organic photo-refraction polymer systems have emerged. Though the macroscopic research to polymer photo-refraction materials has already got considerable development-up till now the photosensitize, electric charge transport and electro-optics molecule have been known very clearly, the systematic research of trap state, polarization and relaxation process has not done yet. Moreover, the trap mechanism and microcosmic process have not been clearly understood, and characterization methods not perfected, which is restricting the deeper research and application of photo-refraction polymer. Applying nonisothermal technology-thermally stimulated depolarization current (TSDC or TSC), thermoluminescence (TL) and dielectric spectroscopy, we try to do some research of carrier trap center and relaxation process of photo-refraction polymer. In the paper, the electrode system of the original TL/TSC measurement instrument is improved, which greatly facilitates sample exchange and increased liquid nitrogen's running and cooling speed. Through long time and repeated practice we finally find an effective method to prepare films. We've synthesized a new kind of organic photo-refraction material nitryl azobenzene grafting PVK and characterized it with IR spectra. We've also synthesized 5OCB and found the optimal mass ratio of PVK/5OCB/C60-49.8:50:0.2, and given the two-beam coupling testing result.