This article reports structure and morphology of copper phthalocyanine (CuPc) and fluorinated copper phthalocyanine (F16CuPc) pn heterojunction. Highly ordered CuPc and F16CuPc polycrystalline thin films with the 2 0 0 plane spacing s of 1.30 and 1.56 nm, respectively, could be continuously grown via an intermediate-phase layer. Compared with CuPc, the intermediate-phase layer is much thinner when F16CuPc is used as the first layer. The rougher the first layer is, the thicker the intermediate-phase layer is. Similarly, the 2 0 0 plane spacings of the intermediate-phase layer are dependent on morphology of the first layer. Furthermore, morphology of the heterostructure is mainly dominated by that of CuPc films. Due to the thicker intermediate-phase layer in the CuPc/F16CuPc heterostructure, the thin fillm transistors (TFT) performance is obviously inferior to that of the F16CuPc/CuPc device. (C) 2008 Elsevier B.V. All rights reserved.