In this work, Fluorine + Antimony doped Tin oxide thin films (SnO2:Sb + F), were deposited on heated glass substrates using the ultrasonic spray pyrolysis technique. Tin(IV)-bis(acetylacetonate) dichloride ((C5H8O2)2SnCl2), was used as source of Tin. The use of the latter reagent was considered important, since its usage had scarcely been reported. Antimony chloride (SbCl3) and Ammonium fluoride (NH4F) were used as sources of the dopants of Antimony and Fluorine, respectively. The properties of the films resulted dependent on the relative amount of these dopants. The films as deposited were polycrystalline, with a low roughness, and showed excellent optical transparency, close to 90%, in the visible region of the electromagnetic spectrum. Fluorine in the films was only detected by Secondary Ion Mass Spectroscopy (SIMS) measurements, and films deposited with 5% of NH4F and 5% of SbCl3 in solution, showed the best electrical properties. An electronic conductivity up to 400 S/cm, and mobility, close to 10 cm2/V sec, were found in the best SnO2 film. An ionized impurity scattering mechanism seems to be responsible for the electronic transport in these films. In addition, the electronic conduction by bulk (or grains), was verified by impedance spectroscopy.

The luminescence and structural properties of layered Y2O3:Eu3+ phosphors, synthesized by a simple evaporation method followed by thermal annealing at temperatures up to 1100 °C, are described for a europium doping concentration of 4.3 at. % as determined by energy dispersive spectroscopy. The intense luminescence emission spectra of these samples are associated with the characteristic intra-electronic energy levels of Eu3+ ion transitions. The dominant emission peak is at 611 nm, corresponding to the 5D0 to 7F2 transition, and the dominant excitation peak is at λexc = 245 nm. A layered morphology was observed in these phosphors by both transmission and scanning electron microscopy studies. The samples have a cubic crystalline structure.

Mesoporous TiO 2 hollow shells were synthesized by a conventional templating method which combines sol-gel coating and selective etching of the silica cores. Pt nanocatalysts were supported on these mesoporous TiO 2 hollow shells varying the metal loading: 0, 1, 3, 5 and 7 % at calcination temperatures of 500 or 900°C. The samples were characterized by transmission electron microscopy, X-ray diffraction, UV-Vis diffuse reflectance spectroscopy, and nitrogen physisorption. The mesostructures were observed by TEM and HRTEM to be smaller than 300 nm and the TiO 2 shells had an average wall thickness of 40 nm. X-ray diffraction spectra revealed a pure anatase phase in samples calcined at 900°C, whereas those calcined at 500°C were amorphous. Under white light (UV and Visible) illumination, photocatalytic hydrogen production was measured from the samples suspended in an aqueous solution of methanol and compared to TiO 2 (P25, Degussa) used as a reference. The highest hydrogen yields were achieved with the crystalline TiO 2 hollow shells annealed at 900°C containing 1 or 7 wt% Pt. The amorphous samples were observed to be inactive, at all metal loadings. Graphical Abstract

Different emission intensities presented in aluminum oxide phosphors corresponding to different concentrations of doping performed with terbium are analyzed. The phosphors were synthesized by the evaporation technique and were characterized by photo and cathodoluminescence, x-ray diffraction, and EDS techniques for different incorporation percentages of terbium as dopant; they show characteristic transitions in 494, 543, 587 and 622nm, corresponding to 5

No abstract