Conductivity of Photographic Emulsions

Abstract

ATTEMPTS to explain the origin of the latent image in sensitive photographic layers often take into consideration the close conjunction of processes (electronic and ionic) present during the formation of the latent image with those concerning photoconductivity or luminescence in the same materials. It is therefore possible to presume that a mutual connexion exists between the so-called photochemical sensitivity of the photographic layer on one hand and photoconductivity or luminescence on the other. This is so, because that part of the photoelectrons which will participate in the formation of the latent image¹ cannot take part in, for example, luminescence and at the same time will influence, depending on the sensitivity of the layer (that is, depending on the number and energy-levels of the active trapping centres for photoelectrons in silver halide crystals), the size and course of the growth of photoconductivity of a definite photographic layer. Similar problems were investigated by Vacek², West and Carroll³ and by Gross⁴.