Abstract :
This review article discusses the fundamental basis of photoconductivity in lead sulphide, telluride, and selenide, and its application in modern highly sensitive infrared detectors. The first part of the paper deals with the manufacture of cells and the processing of photosensitive layers; and with the characteristics of the final detectors, such as response time, sensitivity, and spectral distribution of sensitivity. The factors determining the maximum attainable sensitivity are discussed. The second part covers fundamental semiconducting properties of the three materials, including absorption, activation energies, carrier lifetimes and effective masses; and the theory of photoeffects in layers. Some applications of these detectors are described. An extensive list of references is given.
