Characterization of Pt-doped V_2O_5 thin film for cathode of thin film battery by a direct current reactive sputtering method

摘要

Vanadium oxide (V_2O_5) thin films were deposited on Pt/TiCh/SiCVSi substrates by using direct current reactive sputtering at room temperature as a cathode material. In order to improve the electrochemical properties of the as-deposited cathode films, the co-sputtering of Pt with various radio frequency powers was carried out. The as-deposited films showed amorphous feature with regardless of the amount of Pt dopant as indicated by Fourier transmission infrared and x-ray diffraction measurements. The Pt-doped V_2O_5 film with r.f. power of 50W showed an amorphous PtO_2 phase in the amorphous V2O5 matrix. The increase of Pt doing induced the porous surface structure of as-deposited films. Room temperature charge-discharge measurements based on a half-cell with a constant current clearly indicated that the as-deposited films.with metal Pt dopant showed improvement of the cyclibility although the formation of a-PtC-2 and too porous structure changed the cyclibility to be poor. This result suggested that the amorphous V_2O_5 film growth with the metal Pt dopant is one of the keys for the high performance thin film battery with the V_2O_5 cathode film.