Charge xerography

To prepare the charge generation material of photoreceptor used in xerography, the crude VOPc synthesized at 150 °C for 4 h in the microwave synthesis was acid-treated, and then recrystallized. As shown in Fig. 4, the amorphous VOPc can be obtainol from crude VOPc by acid-treatment and the fine crystal VOPc can he obtained fixim amorphous VOPc by recrystallization. From XRD results, it can be calculated that the crystallite size of fine crystal VOPc is about 18 nm. As shown in Fig. 5, the fine crystal VOPc is well dispersed with uniform size. It indicates that this fine crystal VOPC can be probably used as the chaige generation material of photoreceptor. Thus, further research will be required to measure the electrophotographic properties of fine crystal VOPc. 

For hole transport, many of the first materials used in OLEDs were originally developed for use in xerography. Various models have been proposed to describe charge transport in such materials [75,76]. One of the most common classes of material used is the arylamines,... 

Photoconducting polymers such as poly (JV-vinylcarbazole) are used in xerography or electrophotography, since the photogenerated charge carriers can travel through the polymer film with relative facility before getting immobilized or trapped (Roberts,... 

The most familiar application of amorphous semiconductors will, for many readers, be in the field of replication of printed matter. The xerography process, npon which many modem photocopiers are based, involves the ability of an electrostatically charged plate of amorphous chalcogenide (or similar material) to discharge under illn-mination. Residual charging of illuminated areas is employed in the transfer of ink onto the duplicator paper. Naturally, the mobility of photoinduced carriers in the amorphons semiconductor photoreceptor is of central importance in the validity of the process, and considerable commercial effort has been (and is being) devoted to the study of transport in disordered materials suitable for the process. 

Fig. 10.24. Illustration of the principles of xerography (a) charging the surface with a corona discharge (b) selective discharge by exposing the photoreceptor to the image (c) electrostatic attachment of ink-laden toner particles to the charged regions. The toner is subsequently transferred to paper.

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