Electronic Structure of h-WO3 and CuWO4 Nanocrystals, Harvesting Materials for Renewable Energy Systems and Functional Devices

— The electronic structure of hexagonal WO3 and triclinic CuWO4 nanocrystals, prospective materials for renewable energy production and functional devices, has been studied using the X-ray photoelectron spectroscopy (XPS) and X-ray emission spectroscopy (XES) methods. The present XPS and XES results render that the W 5d-and O 2p-like states contribute throughout the whole valence-band region of the h-WO3 and CuWO4 nanocrystalline materialls, however maximum contributions of the O 2p-like states occur in the upper, whilst the W 5d-like states in the lower portions of the valence band, respectively.