The formation of photographic images in single crystals of lead iodide

Abstract
A recent investigation of the electrical conductivity of small crystals of lead iodide has led to the discovery of an anomalous behaviour in photo-conductivity. The conductivity undergoes a sudden extinction at temperatures between 170°c and 190°c. This appears to be related to the occurrence of photo-decomposition which commences at the same temperature. The micrographs presented in this paper to illustrate photo-decomposition also demonstrate the remarkable localization of the effect. They suggest the possibility of using photo-decomposition in lead iodide crystals to ‘print out’ photographic images, providing a recording process which may have advantages over conventional techniques.