Electronic and optical properties of hafnium indium zinc oxide thin film by XPS and REELS

► XPS and REELS analysis can provide electronic and optical properties of materials. ► ZnO-based transparent conductive oxide thin films amply exhibit the usefulness of XPS and REELS analysis. ► REELS analysis shows the band gap increase from 3.0 eV to 3.5 eV as a result of adding Hf to InZnO.