An application of cathodoluminescence microscopy on morphology of photosensitive dyes on AgBr crystals

• Autorzy: Saijo H. , Shiojiri M.
• Konferencja: Polish-Japanese Joint Seminar on Materials Analysis (1-3.09.1997 ; Warsaw, Poland)
• Języki publikacji: EN

Abstrakty

EN

Silver halides have been a unique material to record images in high qualty and with high sensitivity. However, the silver halides do not have enough sensitivity to exposing lighgt of green to red region. Photosensitive dyes adsorbed on silver halide microcrystals work to absorb light of the wavelength and inject photoelectrons to cause latent images in the substrates. This technique, spectral sensitization, is a key technology of modern photographic materials. Photosensitive dyes, generally cyanine dyes, assemble with their counter ions to form small crystallites, J-aggregates, on the surface of silver halide microcrystals. The incident electrons to the aggregates in an electron microscope produce photon emission, so-called cathodoluminescence (CL). The CL micrographs provided the information on shape, size, nucleation and growth, adsorptin position and perferential adsorption of J-aggregates on AgBr microcrystals. The results agreed well with those of Low-voltage High-resolution Scanning Electron Microscopy and Atomic Force Microscopy. The population of aggregates adsorbed on an AgBr particle varies from almost nine to full coverage. The thickness of J-aggregates crystallites is uniform and depends on a comgimation of dye species and counter ion, and is 2.1nm for thiacarbocyanine with sidium ion, 1.04 nm for thiacarbocyanine with tosyl ion and 0.5 nm for an oxacarbocyanine. However, the area of the crystallite increases with the number of dye molecules in it, and is about (20 ÷ 30)x(30 ÷ 50) nm. The longer edges of the crystallites align along [210] axes of the substrate surface. The crystallites connected linearly on the surface and stacked high to form multi-layered islands or arrays.

• Wydawca: Institute of Electron Technology
• Czasopismo: Electron Technology
• Rocznik: 1998
• Tom: Vol. 31, No. 2
• Strony: 176--182
• Opis fizyczny: Bibliogr. 11 poz.

Twórcy

autor

Saijo H.

autor

Shiojiri M.

• Departament of Electronics and Information Science, Kyoto Institute of Technology Matsugasaki, Sakyo-ku, Kyoto 606 Japan