This paper reports the luminescence properties of spark-processed Si (sp-Si) prepared with different atmospheres such as air, O-2, and N-2 in low vacuum range (50-760 Torr). Three main luminescence bands are observed from spark-processed Si (sp-Si). In addition to the well-known two luminescence bands in the blue/violet peaking at 410 nm and green peaking at 500 nm, a novel UV luminescence band is detected for the sp-Si prepared in N-2. The temperature dependence of photoluminescence (PL) characteristics of the newly detected UV luminescence band is examined. Further studies of photoluminescence excitation (PLE) have been performed and origins of luminescence are discussed based on the experimental results. (c) 2005 Elsevier B.V. All rights reserved.