Strong photoluminescence of nanostructured crystalline tungsten oxide thin films

Strong photoluminescence (PL) is observed in nanostructured crystalline tungsten oxide thin films that are prepared by thermal evaporation. Two kinds of films are investigated-one made of nanoparticles and another of nanowires. At room temperature, strong PL emissions at ultraviolet-visible and blue regions are found in both of the films. Compared with the complete absence of emission of bulk phase tungsten oxide powder under the same excitation conditions, our results clearly demonstrate the quantum-confinement-effect-induced photoluminescence in nanostructured tungsten oxides. (C) 2005 American Institute of Physics.