Xerographic photoreceptor

Koch-Yee Law. Organic photoconductor materials for xerographic photoreceptors (Advanced Tutorial A2). IS and T s Non-Impact Printing Conference 12, San Antonio, Texas, October 27, 1996. 

It was mentioned earlier (Section 3.4) that all materials can be rendered amorphous. What is often not recognized by chemists is that a large variety of materials - catalysts, catalyst supports, xerographic photoreceptors, optical fibres, large-area solar cells and many biominerals - are noncrystalline (Elliott et al, 1986). Noncrystalline solids possess no long-range order and their structure is akin to that of a frozen liquid. Most... 

B Kippelen, J Herlocker, JL Maldonado, K Ferrio, E Hendrickx, S Mery, A Go-lemme, SR Marder, N Peyghambarian. Proc SPIE-Int Soc Opt Eng 3471 (Xerographic Photoreceptors and Organic Photorefractive Materials IV) 22, 1998. 

The phthalocyanines have recently received great attention as chargegenerating materials in xerographic photoreceptors. Copper phthalocy-anine was one of the first dyes to be employed as a photoreceptor and its performance varied as a function of the crystallinity, morphology, and dispersion preparation [40]. 

The first major commercial application of amorphous semiconductors was as the photoreceptor in xerographic copiers and subsequently in laser printers. The early photoreceptors were selenium films, but several other materials were subsequently developed, including ASgSCg and various organic films. Amorphous silicon is a good material for a xerographic photoreceptor (e.g. Shimizu (1985), Pai (1988)) and is used in some commercial copying machines. 

Fig. 10.26. Typical structure of a xerographic photoreceptor showing the blocking layer at the substrate, the surface layer and the photoconductor (Pai 1988).

LeComber (1975) showed that by suitable doping, a-Si could be made n- or p-type. These properties, in conjunction with the fact that plasma-deposition processes are generally amendable to large areas, were such that much of the early interest in a-Si was directed to photovoltaic applications (Carlson and Wronski, 1976 Kuwano. 1986). It was quickly recognized, however, that the requirements for photovoltaic applications were, in many respects, similar to those for xerographic photoreceptors. 

In addition to the chalcogenide glasses, organic materials, and a-Si, other materials have been used as xerographic photoreceptors. The more common of... 

Measurements involving continuous exposures are widely used to determine the radiation sensitivity of xerographic photoreceptors. While the technique has the very considerable advantage of experimental simplicity, it has several fundamental limitations. Of these, the most significant is that exposures of this kind do not correspond to those used in most copiers or printers. Another limitation is that the technique gives no information concerning the time required to discharge the photoreceptor, which is of considerable relevance. A... 

From their discovery in 1927 to the present day, the phthalocyanines have been a significant commercial product. These materials have superior colorant characteristics, as well as exceptional stability to heat and light. Today, applications extend from the traditional inks and paints (McKay, 1989) to xerographic photoreceptors (Gregory, 1988, 1991). Because of their importance as colorants, synthetic methods have been developed for their preparation on a large scale (Moser and Thomas, 1963, 1983 Thomas, 1990). Metal-free... 

The electrophotographic process is initiated by deposition of a uniform surface charge from the corona on the xerographic photoreceptor belt in the... 

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