Electronic structure of tetragonal tungsten bronzes and electrochromic oxides

X-ray photoemission spectra of the band structures of WO3, crystalline Hsub(x)WO3 and the tetragonal and cubic bronzes Msub(x)WO3(M = Li, Na) exhibit great similarity. In the bronzes tungsten 5d conduction band states are occupied. The tungsten 4f core level spectra of these materials have an unusual, but characteristic structure attributed to a combination of final state screening and hydrogen or alkali ion neighbor effects. The band structure of amorphous electrochromic WO3 films differs in characteristic ways from that of the crystalline bronzes. (orig.)