Bi2WO6 thin films grown by high-power InfraRed Nd:YAG pulsed laser deposition: a structural and spectroscopic study

Abstract

We report on the epitaxial growth of Bi2WO6 thin films by Pulsed Laser Deposition using a high-power infrared Nd:YAG laser source. X-ray diffraction investigation confirms that single (00l)-oriented thin films can be obtained on both LSAT and SrTiO3 substrates by using a LaNiO3 adapting layer. Moreover, reciprocal space maps show that the films coherently grow on such substrates with the in-plane lattice parameters fully matching those of the substrates. In-situ x-ray photoemission spectroscopy experiments show that a UHV annealing process makes the film more conductive even though it also affects the Bi:W chemical ratio by reducing the Bi content. Alternately, the conductivity of the films can be effectively tuned by either growing the film in Ar atmosphere or by depositing potassium on its surface without modifying the Bi:W chemical ratio. Our results provide a viable route to synthesize high-quality Bi2WO6 thin films with tailored electronic properties.