The influence of the diamond-like carbon (DLC) thin film on photoconductivity of the copper phthalocyanine (CuPc) multilayer films is studied. The results show that the layer of diamond-like carbon can be used as a passivation film to reduce the influence of environment. The reasons of the changed photoconductivity of azo-polymer/CuPc/DLC multilayer films are discussed. (c) 2005 Elsevier B.V. All rights reserved.