title: Bi(x)La(1-x)VO4 solid solutions: tuning of electronic properties via stoichiometry modifications.
abstract: BixLa1-xVO4 solid solutions were obtained in the form of fine powder via a microwave-assisted hydrothermal route. The presence of a solid solution in the studied system was confirmed using X-ray diffraction (XRD) and optical spectroscopy techniques. Pure BiVO4 and LaVO4 were obtained in the monoclinic form, whereas solid solutions in the tetragonal, zircon-type structure. The optical band gap dependence on the composition of the solid solution is parabolic, thus there is a possibility to tune this parameter in a wide concentration range, from 2.4 to 4.0 eV. An absorption coefficient maximum is also concentration-dependent, possibly, due to the structural disorder of the samples. Solid solutions with Bi(3+) concentration between 11.94 and 32.57 at.% exhibit intense, green luminescence. This indicates the presence of Bi-originated electronic states within the band gap. The value of the conduction band edge potential, measured by both electrochemical impedance spectroscopy and work function measurements, is concentration-independent. Moreover, solid solutions exhibit a photoelectrochemical photocurrent switching effect, thus they may be promising materials for molecular electronics and as dioxygen activators.
authors.affiliation: AGH University of Science and Technology, Faculty of Non-Ferrous Metals, al. A. Mickiewicza 30, 30-059 Kraków, Poland. szacilow@agh.edu.pl.
authors.forename: Przemysław
authors.initials: P
authors.lastname: Kwolek
authors.forename: Kacper
authors.initials: K
authors.lastname: Pilarczyk
authors.forename: Tomasz
authors.initials: T
authors.lastname: Tokarski
authors.forename: Kornelia
authors.initials: K
authors.lastname: Lewandowska
authors.forename: Konrad
authors.initials: K
authors.lastname: Szaciłowski
mesh_terms: D001729:Bismuth / Q000737:chemistry*; D007811:Lanthanum / Q000737:chemistry*; D014638:Vanadates / Q000737:chemistry*
chemical_list: D014638:Vanadates; D007811:Lanthanum; D001729:Bismuth