Research studies on new materials have shown that cerium-vanadium mixed oxides have potential for use as counter-electrodes in electrochromic devices owing to the combination of the excellent stability and transparency of cerium oxides and the high ion-storage capacity of the vanadium oxides. Among them, cerium orthovanadate (CeVO4) has shown its potentiality as an intercalation electrode of suitable structure into which ions can be inserted reversibly, thus balancing the ion-charge capacity required by WO3, which is the colouring electrode in electrochromic devices. In this work, cerium-vanadium stoichiometric oxides (CeO2-V2O5, 1:1 molar ratio) have been used as a target material for r.f.-sputtering thin-film deposition onto suitable substrates. The films obtained have been characterized before and after electrochemical lithium intercalation. Their XPS and x-ray-induced Auger electron spectroscopy spectra have been compared with those obtained with the standard precursor oxides and the results discussed also on the basis of literature data. In order to be able to observe the changes in chemical state and composition expected on film formation, a careful curve-fitting procedure has been used that allows the determination of the background structure and intrinsic satellites for each peak, as reported already in previous papers
Use of XPS for the study of cerium-vanadium (electrochromic) mixed oxides
Speranza, Giorgio
2001-01-01
Abstract
Research studies on new materials have shown that cerium-vanadium mixed oxides have potential for use as counter-electrodes in electrochromic devices owing to the combination of the excellent stability and transparency of cerium oxides and the high ion-storage capacity of the vanadium oxides. Among them, cerium orthovanadate (CeVO4) has shown its potentiality as an intercalation electrode of suitable structure into which ions can be inserted reversibly, thus balancing the ion-charge capacity required by WO3, which is the colouring electrode in electrochromic devices. In this work, cerium-vanadium stoichiometric oxides (CeO2-V2O5, 1:1 molar ratio) have been used as a target material for r.f.-sputtering thin-film deposition onto suitable substrates. The films obtained have been characterized before and after electrochemical lithium intercalation. Their XPS and x-ray-induced Auger electron spectroscopy spectra have been compared with those obtained with the standard precursor oxides and the results discussed also on the basis of literature data. In order to be able to observe the changes in chemical state and composition expected on film formation, a careful curve-fitting procedure has been used that allows the determination of the background structure and intrinsic satellites for each peak, as reported already in previous papersI documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
