Niobium oxide amorphous films were deposited on silicon substrates at a temperature range of 300-400 degrees C by heating a pure niobium foil in a rough vacuum. The films were amorphous in structure and with morphology of vertically aligned nano-columns. This feature resulted in interesting photoluminescence (PL) property in the visible light range. The intensity of the photoluminescence spectrum of the as-deposited amorphous film is small. However, the PL intensity of the same sample after annealing below 500 degrees C increases greatly and consists of two peaks centered at similar to 630 nm (1.97 eV) and similar to 715 nm (1.74 eV). The mechanism for the PL behavior of the amorphous niobium oxide films was also investigated and discussed. (c) 2008 Elsevier B.V. All rights reserved.