p-ZnO thin film formation on Si substrate is investigated using rf magnetron sputtering followed by Zn3P2 diffusion process. In order to form p-ZnO thin film, n-ZnO thin film is initially deposited on Si substrate using rf magnetron sputtering. Then, Zn3P2 source diffusion by closed ampoule technique is performed on ZnO/Si test structure. The electrical and optical characteristics of the ZnO thin films are investigated and the effect of Zn3P2 diffusion on the properties of ZnO thin films are examined. From the analysis results, it is verified that p-type ZnO thin film on p-Si substrate is formed by dopants diffusion. (C) 2002 Elsevier Science B.V. All rights reserved.