In this paper, we have prepared Schottky type ZnO metal-semiconductor-metal (MSM) ultraviolet (UV) detector. The structural, electrical, and optical measurements were carried out. The detector exhibited a peak responsivity of 0.337 A/W at 360 nm and the dark current was about 1 nA under 3 V bias. An ultraviolet-visible rejection ratio was obtained about more than four orders of magnitude from the fabricated detector. The 10 - 90% rise and fall time were 20 ns and 250 ns, respectively. We proposed that the detector had shown a gain, which was attributed to the trapping of hole carriers at the semiconductor-metal interface. (c) 2007 Elsevier Ltd. All rights reserved.