RF-sputtered vanadium oxide thin films: Effect of oxygen partial pressure on structural and electrochemical properties

Vanadium oxide thin films with thickness of about 2000 Angstrom have been p repared by radio frequency sputter deposition using a V2O5 target in a mixe d argon and oxygen atmosphere with different Ar/O-2 ratio ranging from 99/1 to 90/10. X-ray diffraction and X-ray absorption near edge structure spect roscopic studies show that the oxygen content higher than 5% crystallizes a stoichiometric V2O5 phase, while oxygen deficient phase is formed in the l ower oxygen content. The oxygen content in the mixed Ar + O-2 has a signifi cant influence on electrochemical lithium insertion/deinsertion property. T he discharge-charge capacity of vanadium oxide film increases with increasi ng the reactive oxygen content. The V2O5 film deposited at the Ar/O-2 ratio of 90/10 exhibits high discharge capacity of 100 mu Ah/cm(2)-mum along wit h good cycle performance.