ABSTRACT

In Carlson’s original patent (1942), anthracene, S, and mixtures of S and Se were mentioned as photoconducting insulators suitable for latent image formation. Since that time, many different materials have been used as photoreceptors. During the 1960s and early 1970s, the chalcogenide glasses were widely used. All of the early Xerox copiers used either a-Se or As stabilized a-Se. Other materials used in the early development of xerography were dispersions of inorganic particles, mainly ZnO, CdS, and CdSe, in a polymer host. In the past decade, organic materials and a-Si have been increasingly employed. The first commercial use of organic photoreceptors was by IBM in 1970 and Eastman Kodak in 1975. At present, organic photoreceptors are widely used for both low-and high-volume applications. Amorphous Si was introduced by Canon in the early 1980s and is mainly used for mid-volume applications.