一般注記type:Thesis
In this work, the material design direction of photoconductive polymer for photorefractive (PR) composite is proposed. Several different polymers are synthesized and applied to fabricate PR composite to qualify advantage and disadvantage of each material design approach. The monolithic co-polymer with carbazole and nonlinear optical (NLO) is synthesized successfully with high molecular weight by polymer analogous reaction. The approach of using PR composite based on monolithic co-polymer has been proved its effectiveness in loading a high concentration of chromophore without phase-separation. However, response time is decreased due to low photoconductivity. The triphenylamine is chosen to improve the PR properties. Poly(4-(diphenylamino)benzyl acrylate) (PDAA) is synthesized by radical polymerization. Composite based on PDAA shows > 80% diffraction efficiency at a moderate applied field. Shorter wavelength of writing beam gives better PR performances. The demonstration of real-time hologram display is performed successfully with PDDA-based composite devices at low applied field of 25 V/?m. The strategy of using higher highest occupied molecular orbital (HOMO) level polymer is confirmed by comparing two similar polymer with different ionization potential (IP) values. Poly(4-((4-methoxyphenyl)(phenyl)amino)benzyl acrylate) (PMPAA) is synthesized with a comparable molecular weight to PDAA. The methoxy modification in PMPAA does not only raise the HOMO level but also contribute significant improvement in chromophore orientation. The comparison of the two kinds of composite based on PDAA and PMPAA reveals that higher HOMO level of photoconductive polymer does not always lead to better PR performances. The controlling of trap in PR composite is found to be more important to obtain the desired properties.
連携機関・データベース国立情報学研究所 : 学術機関リポジトリデータベース(IRDB)(機関リポジトリ)