Formation and Etching of the Insulating Sr-Rich V5+ Phase at the Metallic SrVO3 Surface Revealed by operando XAS Spectroscopy Characterizations
SrVO3 (SVO) transparent conductive oxide (TCO) thin film, both visible-range optically transparent and highly conductive, shows great potential as a viable alternative to standard ITO (indium tin oxide) in various applications. In this study, our researchers investigated the surface stability of SVO under different gaseous atmospheres, particularly water, using spectroscopy characterizations such as x-ray photoemission (XPS) and operando ambient pressure x-ray absorption spectroscopy (XAS) techniques. Their findings reveal the formation of a few nanometer-thick insulating Sr-rich V5+ layer on the surface of the SVO film over time. To restore the TCO properties, this work demonstrates for the very first time that this undesired phase can be effectively removed through a water etching process, which is successful in both liquid and vapor forms.