ABSTRACT
The xerographic process and the basic photoreceptor requirements for xerography are summarized in this handbook by Borsenberger and Weiss as well as by numerous authors in the past (see, e.g., Tabak et al., 1973; Mort and Chen, 1975; Schaffert, 1975; Weigl, 1977; Berger et al., 1979; Mort, 1984; Scharfe, 1984; Williams, 1984; Pai and Melnyk, 1986; Burland and Schein, 1986; Mort, 1989; Pai and Springett, 1993). There is also an extensive literature on the physics and technology of selenium based photorecep tors (Berkes, 1974; Cheung et al., 1982; Springett, 1984, 1988). In its simplest form, a xerographic photoreceptor consists of an amorphous selenium (a-Se) alloy film deposited by vacuum evaporation techniques onto an aluminum drum. Vitreous selenium alloys are normally thermally evaporated from long stainless steel boats onto heated cylindrical aluminum substrates, which are rotated during deposition. Typically the a-Se film is 5070 μιη in thickness and 100 cm2 in surface area, though areas as large as 1 m2 are used in the largest machines. The fabrication of many photoreceptor drums requires special vacuum coaters that can accommodate a large number of drums (e.g., 50 or more) and can achieve the required film composition and xerographic characteristics with high yield.
