Al-Nb containing mixed oxides were grown by anodizing sputter-deposited Al-Nb alloys of different compositions. A photoelectrochemical investigation was carried out in order to estimate the band gap, flat band potential, and conductivity type of these oxides as a function of their composition. The dependence of the band gap on the composition of mixed sp-d metal oxides has been rationalized by using a semiempirical correlation between the difference of electronegativity and band gap of oxides proposed in the literature some years ago and recently tested for regular d-d metal mixed oxides. The band gap increase observed as a function of Al content into the oxides seems mainly depending on the monotonic shift of the conduction band mobility edge, E CBM, derived from 5d orbitals of Nb5+ in the presence of an almost constant energy location of the valence band mobility edge, E VBM.
|Numero di pagine||10|
|Rivista||JOURNAL OF PHYSICAL CHEMISTRY. C|
|Stato di pubblicazione||Published - 2013|
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