Abstract: An ammonia-modified titanyl phthalocyanine for use in preparing charge generating layer of a photoreceptor is disclosed. The ammonia-modified titanyl phthalocyanine is obtained by a process comprising the following steps: (a) reacting titanium tetrachloride with halogen-containing naphthalene to obtain an unmodified titanyl phthalocyanine; (b) dispersing the unmodified titanyl phthalocyanine in an organic solvent; and (c) subjecting the unmodified titanyl phthalocyanine to an ammonia-induced complexation-mediated crystal transformation so as to obtain the ammonia-modified titanyl phthalocyanine. The ammonia-induced complexation-mediated crystal transformation step can be achieved by either bubbling ammonia gas through the titanyl phthalocyanine-containing organic solution or by adding an ammonia-saturated aqueous solution to the titanyl phthalocyanine-containing organic solution. The ammonia-modified titanyl phthalocyanine is characterized by having Bragg diffraction angles of 7.5, 9.3, 13.6, 14.3, 17.9, 24.

Abstract: Organic photoreceptors of the functionally separated laminated type containing a hydrazone compound in the charge transport layer thereof which provides low crystallinity and improved sensitivity, durability, and reproducibility. The hydrazone compound disclosed in the present invention is presented by the following general formula (I): ##STR1## wherein R.sub.1 represents a substituted or unsubstituted C.sub.1 -C.sub.4 alkyl group, R.sub.2 represents a hydrogen atom, or an alkyl or alkoxy group; n is an integer of either 1 or 2; R.sub.3 and R.sub.4 each independently represents a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group or a substituted or unsubstituted aralkyl group; or alternatively R.sub.3 and R.sub.4 form a substituted or unsubstituted aromatic heterocyclic ring residue cojointly with the nitrogen atom to which they are bonded.