Growth of tungsten selenide films through pyrolytic conversion and anodic electrooxidation of ammonium selenotungstate ((NH sub(4)) sub(2)WSe sub(4))

W sub(x)Se sub(y) thin films have been prepared by the spray pyrolysis and anodic electrodeposition of solutions of ammonium selenotungstate, (NH sub(4)) sub(2)WSe sub(4), with y/x usually between two and three for the sprayed films and y/x > > 1 for the electrodeposited films. The sprayed films indicated regions of crystalline WSe sub(2) and have optical absorbance spectra consistent with a mixture of WSe sub(2), WSe sub(3), and selenium. The electrodeposited films are totally amorphous, highly photoconductive, and have optical absorbance spectra typical of amorphous or vitreous selenium. The sprayed films transform into WO sub(3) at temperatures greater than 350 degree C in the presence of oxygen wile the electrodeposited films tend to evaporate and/or decompose upon annealing.