New approach to silver halide photography using radical cation chemistry*
I. R. Gould1,**, J. R. Lenhard2, A. A. Muenter2, S. A. Godleski2, and
1Department of Chemistry and Biochemistry, Arizona
State University, Tempe, AZ 85287-1604, USA; 2Research Laboratories,
Eastman Kodak Company, Rochester, NY 14650-2109, USA
Abstract: A new mechanism for spectral sensitization of silver
halide is described, which can potentially double the sensitivity of
photographic emulsions. The photooxidized sensitizing dye is trapped
using an organic donor molecule, which fragments to form a cation and
a reducing radical, which injects an electron into the conduction band
of the silver halide. In this way, two conduction-band electrons can
be produced for each absorbed photon.
*Lecture presented at the XVIIIth IUPAC Symposium on
Photochemistry, Dresden, German , 22-27 July 2000.Other presentations
are published in this issue, pp.395-548.
** Corresponding author