Abstract
A novel near-infrared sensitive photoreceptor incorporating titanium phthalocyanine with a new polymorph named Y-fom has been developed. Y-form titanium phthalocyanine compounds are metastable and have the deepest red-shifted absorption peak among other polymorphs. The dobuble-layered photoreceptor using Y-form titanium phthalocyanine exhibited very high sensitivity in the wide spectral regian from 600 nm to 850 nm (E1/2 = 1.0 erg/cm2), low dark decay and excellent cyclic stability over 100,000 prints. In particular, the photoreceptor showd very high quantum efficiency which is over 0.9 in the high electric field region and little dependence of the photosensitivity on the ionization potential (Ip) of carrier transport materials (CTM). It was suggested that these characteristics were caused by the high carrier generation efficiency and the high μτ product.
