Sensitization of Photoconduction in Polymers

Abstract

Abstract Photoconductivity can be induced in most materials by employing radiation in an appropriate region of the electromagnetic spectrum. The radiation has to be sufficiently energetic to promote electronic transitions in the material, this being the first step in photoconduction phenomena. Thus, high-energy radiation, such as x rays and gamma rays, produces “photoconductivity,” i.e., conductivity induced by absorbed photons, in most materials. As the photon energy decreases through the UV, visible, and IR regions, many materials fail to respond when the photon energy becomes too small to excite the lowest lying electronic transitions in the material. As a class, many easily fabricated polymers have their lowest energy electronic transitions in the UV and vacuum-UV region of the electromagnetic spectrum. Polymers having electronic transitions in the visible region are often intractable and not readily fabricated into films and other useful forms. Consequently, much attention has been given to “sensitiz...