Design and Characterization of Photorefractive Polymer Composites

フォトリクラクティブポリマー複合体の設計と評価

2014-09-25

2014-09-25

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.

博士(工学)

京都工芸繊維大学

14303甲第719号

http://hdl.handle.net/10212/2193

en

ETD

Thesis or Dissertation

Thesis