Abstract: Nonlinear enhancement of photosensitivity were observed in organic photoreceptors based on TiOPc/VOTPP composite. Absorption spectra revealed no evidences of interactions between the electronic states of TiOPc and VOTPPunder ground state, X-ray diffraction analyses didn't show the changes in their condensed states in composite photoreceptors. Photoinduced discharge experiment indicated that the nonlinear effect was ascribed to the contribution of photogenerated carriers resulted from the excitation of gap states, which were intensified by the composing of heteromolecules. The data obtained from XPSmeasurement on composite materials suggested that there existed a fractional charge transition from TiOPc to VOTPP molecules, such photoinduced charge transfer between the two components was another factor related to the nonlinear effect. This synergetic enhancement effect provide a strategy for designation of novel photoconductive materials and devices driven in a low field based on weak electron donor/weak electron acceptor composites.

Key words: Synergetic enhancement, Photosensitivity, Composite