Critical separation for efficient Tm^3+-Tm^3+ energy transfer evidenced in nanostructured Tm^3+:Al_2O_3 thin films

Critical separation for efficient Tm3+ -Tm3+ energy transfer evidenced in nanostructured Tm3+: Al2O3 thin films.

Nanostructured amorphous Al oxide (a-Al2O3) thin films doped with Tm3+ were synthesized by alternate pulsed laser deposition. The Tm3+ ions have been deposited in layers with in-depth separation ranging from 0.75 to 6 nm. The films show two broad emission bands originated from the Tm3+ 3H4-->3F4 and 3F4-->3H6 transitions. Their intensity increases at a similar rate and the lifetimes are not mod...

Energy transfer up-conversion in Tm3+-doped silica fiber

A study of the mechanisms responsible for the infra-red to near infra-red up-conversion in thulium doped silica fibres is presented. Up-conversion luminescence was observed from the H4 level of Tm under 1586 nm pumping into the F4 level. The quadratic dependence of the up-conversion luminescence at 800 nm on the 1800 nm luminescence from the F4 level confirms that the H4 level is populated by a...

Energy transfer efficiency in YF3 nanocrystals: Quantifying the Yb3+ to Tm3+ infrared dynamics

Nanostructured hybrid ZnO thin films for energy conversion

We report on hybrid films based on ZnO/organic dye prepared by electrodeposition using tetrasulfonated copper phthalocyanines (TS-CuPc) and Eosin-Y (EoY). Both the morphology and porosity of hybrid ZnO films are highly dependent on the type of dyes used in the synthesis. High photosensitivity was observed for ZnO/EoY films, while a very weak photoresponse was obtained for ZnO/TS-CuPc films. Des...

Preparation and Characterization of Downconversion Luminescent LaVO4: Tm3+ , Yb3+ and Tm3+ /Yb3+ Nanosheets

Tm3+ , Yb3+  and Tm3+ /Yb3+  doped LaVO4 nanostructures were synthe- sized for the first time by using the hydrothermal method with the aid of La(CH3CO2)3 as  lanthanum source in presence of oleic acid as surfactant. The products were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), photoluminescence (PL) spectroscopy and ...