Strontium Aluminate Persistent Luminescent Single Crystals: Linear Scaling of Emission Intensity with Size Is Affected by Reabsorption.

The green-emitting SrAlO:Eu,Dy phosphor is the most widely used and well-studied persistent luminescent phosphor available today. Recent efforts to boost its performance in terms of luminescence intensity and duration are challenged by complex loss mechanisms, including the optically stimulated release of previously trapped charges by excitation light. Here, we present minimally scattering SrAlO:Eu,Dy single crystals, which, as opposed to powder phosphors, allow to profit from a so-called volume effect, resulting in a significantly increased emission intensity.

On a local (de-)trapping model for highly doped Pr radioluminescent and persistent luminescent nanoparticles.

Trivalent praseodymium exhibits a wide range of luminescent phenomena when doped into a variety of different materials. Herein, radioluminescent NaLuF4:20%Pr3+ nanoparticles are studied. Four different samples of this composition were prepared ranging from 400-70 nm in size.

Broadband infrared LEDs based on europium-to-terbium charge transfer luminescence.

Efficient broadband infrared (IR) light-emitting diodes (LEDs) are needed for emerging applications that exploit near-IR spectroscopy, ranging from hand-held electronics to medicine. Here we report broadband IR luminescence, cooperatively originating from Eu and Tb dopants in CaS. This peculiar emission overlaps with the red Eu emission, ranges up to 1200 nm (full-width-at-half-maximum of 195 nm) and is efficiently excited with visible light.

Microwave-assisted synthesis followed by a reduction step: making persistent phosphors with a large storage capacity.

The performance of impurity doped luminescent materials, or phosphors, depends on the composition and crystallinity of the host compound, as well as on the distribution and valence state of the dopant ions. This is particularly true for persistent phosphors, where both luminescence centers and charge trapping defects are required. Here we show that splitting the synthesis procedure in two separate steps offers a simple way to obtain efficient persistent phosphors which are superior to phosphors prepared via a conventional solid state synthesis using a single step.

Optically Stimulated Nanodosimeters with High Storage Capacity.

In this work we report on the thermoluminescence (TL) and optically stimulated luminescence (OSL) properties of β-Na(Gd,Lu)F:Tb nanophosphors prepared via a standard high-temperature coprecipitation route. Irradiating this phosphor with X-rays not only produces radioluminescence but also leads to a bright green afterglow that is detectable up to hours after excitation has stopped. The storage capacity of the phosphor was found to be (2.

Counting the Photons: Determining the Absolute Storage Capacity of Persistent Phosphors.

The performance of a persistent phosphor is often determined by comparing luminance decay curves, expressed in cd/m 2 . However, these photometric units do not enable a straightforward, objective comparison between different phosphors in terms of the total number of emitted photons, as these units are dependent on the emission spectrum of the phosphor. This may lead to incorrect conclusions regarding the storage capacity of the phosphor.