M. I. Martinez-Rubio

Rare-earth element anti-Stokes emission from three inverse photonic lattices

The fabrication of a two-dimensional photonic lattice of ZrO2:Er3+ on a silicon substrate and two three-dimensional photonic lattices, ZrO2:Eu3+ and TiO2:Er3+, are described. It is demonstrated that, for the two-dimensional lattice, photonic properties dependent on the lattice are not present, although another effect that was dependent on the structure is discussed. For the two three-dimensional photonic lattices, the position of the photonic stopband relative to the emission bands of the anti-Stokes phosphors is shown to be crucial in controlling emission properties. In the case of the ZrO2:Eu3+ lattice, where the stopband was close to both the emission and the exciting wavelengths, the intensities of both were affected. However, for the TiO2:Er3+ lattice, where the stopband was far from the exciting and emission wavelengths, no such effect was seen. It was concluded from this work that it should be possible to prepare unconverting photonic lattices with stopbands that extend the lifetimes of certain excited states by inhibiting spontaneous emission from them, thereby facilitating enhanced upconversion efficiency.

4.3: Factors Affecting Efficiency in Submicron Phosphors: Implications for Screens for High Definition Displays

Studies on phosphor particles in the range 0.05 to 0.35µm prepared from spherical particle precursors provide strong evidence that the main factors affecting light output are crystallinity, orientation, of the crystallite, and space between particles (in close packed arrays). These findings should be applicable to all high resolution phosphors.

P-51: A Novel Synthetic Method for the Production of Y2O3: Eu Phosphor particles of a Controlled Size using Copolymer Microgels of NIPAM

A novel method for preparing the luminescent red Y2O3: Eu phosphor using copolymer microgels of NIPAM is described. An extensive range of spherical particle sizes (from 0.1 to 1 μm) can be produced using copolymer microgels of NIPAM and AMPS. To produce spherical Y2O3: Eu phosphor particles less than 100 nm in diameter, the copolymer microgel used was NIPAM and Acrylic acid (AAc). The dependence of luminescent intensity on particle size is also reported.

4.4: Photonic Phosphor Crystals for Display Applications

It is shown that photonic phosphor crystals potentially offer a number of opportunities for improving photoluminescent, electroluminescent and cathodoluminescent devices. The synthesis of 3-dimensional photonic phosphor crystals is discussed and examples of T.E.M. micrographs and optical diffraction patterns are presented. The modification of the emission properties of these crystals due to their microstructure is discussed.

LP-4: Late-News Poster: The First Cathodoluminescence Spectra from Photonic Band Gap Phosphors for Low Voltage Applications

It is demonstrated under e-beam excitation at low voltages that, using cubic Y2O3: Eu as an example, photonic phosphor crystals offer the opportunity of altering the emission band signature of the phosphor. The conclusion is that nano-structured phosphor lattices can now be designed and tailored for low voltage applications.

P-55: A New Test for the Presence of Eu3+ in Eu2+ Doped Phosphors. Eu3+ has been found in Plasma (BaMgAl10O17:Eu2+) and Long Persistence (Sr4Al14O25:Eu2+, Dy3+) Phosphors

Stokes and anti-Stokes emission from Eu3+ doped lattices has been observed on excitation with the 632.8 nm line of a He/Ne laser. These lattices include Y2O3, YNbO4 and YVO4. A test for Eu3+ in Eu2+ phosphors has been developed enabling the assessment of purity of Eu2+ containing long persistence and plasma phosphors. This has implications for new synthetic routes to these phosphors.