Compositions of Cu-Cu2O crystal films were fabricated using electrochemical deposition (ECD) with a strategy of potential pulse settings. The Cu-Cu2O films were prepared by controlling the potentials and deposition periods of ECD processes. Intensities of Cu and Cu2O crystals were revealed by X-ray diffraction (XRD) spectral data. Results demonstrated that the Cu and Cu2O crystal compositions were significantly influenced by the potential and deposition period settings. Polycrystalline Cu2O films were formed by the ECD at all tested potential settings. However, Cu-Cu2O crystals were formed at potential more negative than -0.4 V and with long deposition times. The grain sizes of Cu2O and Cu crystals fabricated by ECD were estimated to be 50 and 51 nm, respectively. We verified that the reaction mechanism of Cu2O occurred in the solution phase, and Cu2O transformed into Cu in the solid phase inside the deposition films. The compositions of Cu-Cu2O crystal films can be controlled by a potential pulse strategy with adjusted potential range and pulse period settings. The formation of Cu-Cu2O crystal films during ECD was also discussed. (C) 2018 Elsevier Ltd. All rights reserved.