Deposition of heterostructures of SnO2 and TiO2 doped with trivalent lanthanides, in the form of thin films

Abstract

The main objective of this project is the knowledge about the properties of thin films of SnO2 and TiO2, with and without doping of Sb5+ and trivalent lanthanides (Ln3 +), respectively, which will be combined in the form of heterostructures. It involves the management of deposition techniques, with subsequent characterization of SnO2 and TiO2 thin films individually, and consequently improvement in the properties of these semiconductor oxides when coupled in the form of heterostructures, particularly with regard to the photoinduced electrical properties of both materials. Although there are reports concerning the use of this system for application as a gas sensor, the main objective here is related to the knowledge of the photoinduced electric transport properties of this system, when compared with those obtained by these semiconductors oxides used independently. This assembly is aimed for optoelectronic applications, not discarding the possibilities of using this knowledge to propose gas sensing in the future. In order to characterize the semiconductors both separately and in the heterostructure form, X-ray diffraction measurements, optical transmittance in the UV-Vis-IV region (250-3500 nm), photoluminescence, scanning electron microscopy and atomic force microscopy will be preformed, in addition to the electric characterization itself, which will be basically achieved through optically excited electrical transport measurements. Recently we acquired a He-Cd (325nm) laser, which should address a key issue of sample excitation, since ultraviolet excitation energy will be done close to the fundamental bandgap edge of these materials. In general, the problem addressed is unique and should provide knowledge with high potential applicability for technological application. (AU)