This article reports the preparation of three-dimensional (3D) mesoporous zinc oxide (ZnO) films and their application in solar cells. The films were obtained through electrochemical deposition in DMSO solutions by using PS colloidal crystal as templates. The ZnO films with inverse opal (10) structure were obtained after removing the templates by thermolysis. The ordered porous ZnO films were used to prepare hybrid solar cells by infiltrating the films with poly(3-hexylthiophene) (P3HT) or P3HT:ZnO nanocomposite. Results showed that the interpenetrating network of both ZnO(10) and P3HT can form continuous pathways for electron and hole transport. By infiltrating a P3HT:ZnO nanocomposite into the porous ZnO films, the photocurrent of the solar cell can be dramatically improved. The cell shows the V-oc and I-sc of 462 mV and 444.3 mu A/cm(2), respectively. By using a 420 nm cutoff filter, the cell retains about 80% and 50% of its original V-oc and I-sc after continuous white-light illumination (100 mW/cm(2)) for 10 h. Stability of the device under above conditions was estimated to be 51 h. (C) 2007 Elsevier B.V. All rights reserved.