We report the photoconductive properties and photorefractive grating response time of a polymer mixture composed of 40-wt. % dissolved diethylamino-benzaldehyde diphenyl hydrazone (DEH) and the non-cross-linking epoxy polymer Bisphenol anitroaminostilbene. The films have improved photoconductive sensitivities as high as (W fi) at a wavelength of 650 nm with a corresponding reduction of the grating response time constant to 0.11 + 0.02 s at an intensity of 1 W/cm2. The nitro-aminostilbene chromophore is deduced to be the source of photogenerated charge carriers on the basis of a comparison of the wavelength dependence of the photoconductivity and absorption coefficient. Degradation of the photoconductivity and the dark conductivity as well as of the photorefractive speed with sample age is attributed to precipitation of the DEH; this explanationis supported by x-ray diffraction observations of crystal growth in the polymer.
|Original language||English (US)|
|Number of pages||9|
|Journal||Journal of the Optical Society of America B: Optical Physics|
|Publication status||Published - Jun 1994|
ASJC Scopus subject areas
- Statistical and Nonlinear Physics
- Atomic and Molecular Physics, and Optics