Calcination-free micropatterning of rare-earth-ion-doped nanoparticle films on wettability-patterned surfaces of plastic sheets

Tamm Plasmons Directionally Enhance Rare-Earth Nanophosphor Emission

Rare-earth-based phosphors are the materials on which current solid-state lighting technology is built. However, their large crystal size impedes the tuning, optimization, or manipulation of emitted light that can be achieved by their integration in nanophotonic architectures. Herein we demonstrate a hybrid plasmonic-photonic architecture capable of both channeling in a specific direction and enhancing by eight times the emission radiated by a macroscopically wide layer of nanophosphors. In order to do so, a slab of rare-earth-based nanocrystals is inserted between a dielectric multilayer and a metal film, following a rational design that optimizes the coupling of nanophosphor emission to collective modes sustained by the metal-dielectric system. Our approach is advantageous for the optimization of solid-state lighting systems.

Alternate Calcification in Microcapillaries for the Fabrication of Hydroxyapatite Films without Light Exposure, Calcination, or Applied Voltage

We discuss an alternate method for calcification in microcapillaries for fabricating calcium phosphate films using silicone molds and calcifying solutions. Calcium phosphate films with a line/space of 5-50 µm were fabricated by controlling the concentrations of calcium chloride and sodium phosphate solutions. Plate-type crystals of hydroxyapatite were grown when the calcium phosphate films were immersed in hydroxyapatite precursors. In the initial stage of hydroxyapatite crystal growth, the c-plane of the crystals was grown parallel to the substrates, and subsequently the growth followed with the c-plane growing perpendicular to the substrates. In narrow capillaries, dendritic structures were formed with a tendency to grow in a direction parallel to the direction of the microcapillaries. This technique is useful in the micropatterning of biocompatible ceramics with a minimized material consumption and a short fabrication time.

Transparent nanophosphor films with high quantum efficiency through cold compaction

Compaction of nanophosphor coatings by means of cold isostatic pressing is shown to dramatically improve their optical and mechanical properties.