Effects Related to the Corona Discharge

Decreased charge acceptance of dual-layer photoreceptors with N,N -dipheny l-N,N -bis(3 -methylphenyl)-( 1,1 -bipheny l)-4,4 -diamine (TPD) containing transport layers after extended corona exposures has been reported by Pai and Yanus (1984). This effect was reduced by the addition of a thin polymer surface layer doped with bis-(2-methyl-4-N,N-diethylaminophenyl)phenyl-methane. Ong et al. (1989) described a similar effect with an inverse dual-layer photoreceptor. In this case, the surface layer contained an electron transport 

Takenouchi et al. (1988) described a dual-layer photoreceptor in which transport-layer ozonolysis occurred. The transport layer contained substituted p-styryltriphenylamines, Fig. 11, which reacted as shown. Fatigue was manifested as a residual potential that increased with ozone concentration The 

Osawa and Doi (1992) described a surface layer of plasma-polymerized amorphous C over the transport layer to retard ozone interactions with the transport material along with increased transport material at the interface to compensate for any material that may be destroyed. The reasoning is that without a protective surface layer, the transport layer is destroyed by ozone but the surface is continually abraded so the cycling characteristics are relatively unaffected. However, in an overcoated photoreceptor the surface layer cannot be worn away and destruction of transport material by ozone results in a rising residual potential with cycling. This effect can be reduced by having a higher concentration of transport material at the interface. 

Yoshizawa et al., 1994), and heteroaromatics such as substituted pyrazines (Ikezue and Nakamura, 1995) and quinoxalines (Yoshida et al., 1995). 

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