Diphenoquinone Derivatives and Their Applications as Charge Transport Material in Single-layered Organic Photoreceptor

Abstract

A series of diphenoquinone derivatives were synthesized and their molecular structures were confirmed with IR, NMR and EA. The diphenoquinone molecules were characterized by asymmetrical structures and found highly soluble in common organic solvents and polymers. They could be dissolved in polyesters, like PC (polycarbonate), Vylon200 (a polyester) and etc., at high concentrations above 40 wt%. The diphenoquinone derivatives were used as electron transport material (ETM) and incorporated together with a hole-transport material (HTM) and a charge generation material (CGM) into either PC or Vylon 200 to form a single-layered organic photoreceptor. Xerographic performances of the single-layered multi-components photoreceptor were systematically investigated. For the ETM, HTM and CGM doped single-layered photoreceptors, their photosensitivity was strongly dependent on ETM concentration. Half decay exposure dropped down sharply with increasing ETM concentration and reached minimum when ETM's concentration was 10 wt% and then slightly increased at even higher ETM concentrations. When exposed at 780 nm, the lowest half decay exposures of positive- and negative-charging were 2.2μJ/cm2 and 2.8μJ/cm2, respectively. For the HTM or ETM and CGM doped single-layered photoreceptor, charge generation was localized in the surface of photoreceptor and the bulk of photoreceptor acted only as the space for charge transport when CGM's concentration was 15wt% or higher. This kind of single-layered photoreceptor had separated charge generation and transport functions and worked very much like a dual layered photoreceptor. Half decay exposure was found a decreasing function of CTM's concentration. The lowest half decay exposure under optimized conditions was 9.6μJ/cm2 and 0.59μJ/cm2 by using ETM's and HTM's at 780nm wavelength with excellent xerographic performances.