Search

A series of (Gd, Y, Yb, Tb, Ce)3Al2Ga3O12 compositionally disordered compounds with a garnet structure were prepared in the form of ceramics by sintering in oxygen at 1650 °C for 2 h and studied for the luminescent properties and interaction of ions entering the matrix host. The luminescence features of Ce3+ ions were found to be strongly dependent on the Yb concentration. Photoluminescence and scintillation kinetics are characterized by subnanosecond kinetics when the Yb index in the compound exceeds X = 0.3. It opens an opportunity to create an extremely fast and dense scintillation material emitting in a visible range. A further decrease in the Yb index in the compound leads to an increase in the intensity of Yb3+ infrared (IR) emission, whereas Ce3+ and Tb3+ ions contribute to the luminosity of the material by overlapping intra- and intereconfiguration luminescence bands in the spectral range of 300–700 nm. This finding opens an opportunity to create converter materials tolerant to the corpuscular radiation of isotope sources, providing a high efficiency of electric current production when coupled with a silicon photovoltaic element. The compounds were engineered at the nanoscale level, providing control over electronic excitation transfer between luminescent ions. [ABSTRACT FROM AUTHOR]

Also related to nonlinear processes, Yang I et al. i outline in another Perspective the state of the art of rare-earth-doped upconversion (UC) nano- and microparticles.[18] Specifically, authors provide the main keys that determine the luminescence efficiency of single UC systems. Our key physiological functions and economic activity depend on the constant driving force of light.[1] Over the last few decades, incandescent and fluorescent lamps have been surpassed by electroluminescent semiconductors, giving birth to a new technology, so-called Solid State Lighting (SSL). [Extracted from the article]

The aluminate perovskites YAlO3 (YAP) and LuAlO3 (LuAP) have been identified as potential scintillator materials due to their high light output and short decay time. However, the performance of these materials is significantly reduced by point defects. In this paper, atomistic simulations provide insight into the types of point defects that are expected under various conditions in YAP and LuAP, as well as other REAlO3 compounds (where RE denotes a rare earth ion ranging from Lu to La or Y). For example, we predict that cation antisites are the dominate intrinsic defect for smaller REAlO3 compounds, with the concentration of Schottky-type defects increasing for compounds with larger RE ions. We also predict that cation vacancies will be present in association with the oxidation of the Ce activator. From these results, we show how defects affect different aspects of the scintillation process. Our aim is to provide information that can be used to aid in the intelligent optimization of this family of scintillator compounds. [ABSTRACT FROM AUTHOR]

X-ray luminescence from CdTe nanoparticles is observed when CdTe nanoparticles are encapsulated into BaFBr:Eu2+ phosphors. In contrast, negligible x-ray luminescence is observed from the unencapsulated nanoparticles, either in solution or in solid form. The origin of the x-ray luminescence is attributed to the effective energy transfer from Eu2+ ions to CdTe nanoparticles in the nanocomposite materials. The x-ray luminescence of these nanocomposites is dose dependent and the emission wavelength is size adjustable which may allow use as a type of dosimeter for both in vitro and in vivo applications. [ABSTRACT FROM AUTHOR]