ABSTRACT
Figure 27 A comparison of TiO phthalocyanine polymorphs showing (a) x-ray diffrac tion patterns, (b) absorption spectra, and (c) the spectral dependence of the xerographic sensitivity. For comparison, T-metal-free phthalocyanine is included. The sensitivity is defined as the reciprocal of the energy required to discharge the photoreceptor to V0/2. (After Fujimaki et al. Reprinted with permission from J. Imag. TechnoL, 77, 202 (1991). Copyright 1991, Society for Imaging Science and Technology.)
sensitivities. Interestingly, all materials exhibit relatively high rates of dark discharge and high sensitivity, but the 7-and amorphous forms are clearly better. The (3-had lower sensitivity as well as a lower rate of dark discharge, but it had the advantage of ease of photoreceptor fabrication and stability with cycling. Photo receptors were also prepared using higher ionization potential transport layers with lower mobilities. In these materials, lower sensitivities were observed.
