Photoelectric properties of organic-polysilane quantum structures embedded in glassy matrices and their application to optical devices

本研究的主要成果如下：(1)建立了制备杂化薄膜所必需的嵌段共聚单体[poly(methylphenylsilane-co-maethacryloxypropyltriethoxysilane)，(MPS-co-MPTS)的合成路线。(2)确定了P(MPS-co-MPTES)在聚硅烷-二氧化硅杂化薄膜中抑制光诱导降解的适宜组成。(3)时间分辨光致发光测量表明，随着聚硅烷浓度的降低，激子扩散常数减小。(4)在室温下观察到了聚硅烷-二氧化钛杂化薄膜的光电导。研究发现，由于聚硅烷/二氧化钛界面处的光致电荷转移，聚硅烷-二氧化钛杂化薄膜的光电流比聚硅烷-二氧化硅杂化薄膜提高了约1000倍。这种光导特性使这些混合薄膜有可能应用于光电器件，如光电传感器和太阳能电池。(5)由于聚硅烷的光化学反应，在强紫外光照射下，聚硅烷-无机玻璃杂化薄膜的折射率发生了光致变化。这些特性在聚硅烷薄膜中是没有的。这种光致变化使我们能够制作出可图案化的光波导。(6)发现了聚硅烷-二氧化硅杂化薄膜在强偏振紫外光作用下的光致发光二向色性。(7)成功制作了用于宽带光通信的关键器件，如光栅光波导、多层滤光片等。利用紫外光的全息曝光可以很容易地制作出这种光栅，适用于液晶取向层和分布反馈激光器。

The main results obtained through this research are itemized below, (1) A route for synthesis of a block copolyiner [poly(methylphenylsilane-co-maethacryloxypropyltriethoxysilane), (MPS-co-MPTES)], which is essential for the fabrication of hybrid thin films, has been established. (2) Appropriate compositions of P(MPS-co-MPTES) in polysilane-silica hybrid thin films for the suppression of photoinduced degradation have been determined. (3) Time-resolved photoluminescence measurements have revealed that the exciton diffusion constants become lower with decreasing polysilane concentration. (4) Photoconduction in polysilane-titania hybrid thin films has been observed at room temperature. It has been found that photocurrent in polysilane-titania hybrid thin films is increased by about 1000 times in comparison with that in polysilane-silica hybrid thin films because of photo-induced charge transfer at polysilane/titania interface. Such photoconductive properties make it possible to apply these hybrid thin films to photoelectric devices such as photosensors and solar cells. (5) Photo-induced refractive index changes have been found in polysilane-inorganic glass hybrid thin films under intense ultra-violet (UV) light irradiation because of photochemical reaction of polysilane. These properties have not been found in polysilane thin films. The photoinduced change enables us to fabricate patternable optical waveguide. (6) Photoluminescence dichroism in polysilane-silica hybrid thin films induced by intense polarized UV light has been found. (7) Key devices for broad band optical communication such as grating waveguides and multilayer optical filters have been successfully fabricated. The gratings are easily prepared by holographic exposure of UV light and are applicable to liquid crystal alignment layers and distributed feedback lasers.