Diamond-like carbon (DLC) films were deposited on Al substrates by electrodeposition technique under various voltages. The surface morphology and compositions of synthesized. films were characterized by scanning electron microscopy and Raman spectroscopy. With the increase of deposition voltage, the sp(2) phase concentration decreased and the surface morphology changed dramatically. The influence of deposition voltage on the. field electron emission (FEE) properties of DLC films was not monotonic due to two adverse effects of deposition voltage on the surface morphology and compositions. The DLC film deposited under 1200 V exhibited optimum FEE property, including a lowest threshold. field of 13 V/mu m and a largest emission current density of 904.8 mu A/cm(2) at 23.5 V/mu m. (C) 2008 Elsevier B. V. All rights reserved.