APVV (Research and Development Support Agency)

Acronym: WLEDMAT

Coordinator: Dr. Robert Klement

Team: Dagmar Galusková, Ing. PhD., Jozef Kraxner, Ing. PhD., Michal Žitňan, Mgr. PhD., Ali Talimian, Dr., Branislav Hruška, Ing. PhD., Ivana Petríková, Ing PhD., Aleksandra Nowicka, Mgr., Jaroslava Michálková, Ing., Petr Chrást, Mgr., Nibu Puthenpurayil Govindan, Mgr., Fatih Kurtuldu, Mgr., Dušan Galusek, prof. Ing. DrSc., Anna Prnová, Ing. PhD., Peter Švančárek, Mgr., PhD., Monika Michálková, Ing. PhD., Jana Valúchová, Ing. PhD., Mária Chromčíková, Ing. PhD., ÚACH SAV, ÚMV SAV

Dates: 2018- 2022

Abstract: The project is focused on research and development of novel glass and glass-ceramic rare-earth aluminates-based luminescent materials for white light-emitting diodes (pc-WLED), especially materials with efficient red emission, which could improve CRI index compared to the known commercially produced phosphors. Phosphors will be prepared in the form of glass microbeads. The structure of undoped alumninate glasses in the system Al2O3-RE2O3 will be studied by spectroscopic methods. Thermal properties and kinetics of crystallization will be also studied. In order to preparer glass-ceramics materials with required properties, the conditions of crystallization process will be investigated and optimized. Photoluminescence properties of glass and glass-ceramic rare-earth and transition metal ions doped materials will be studied in detail. Special attention will be paid to study of relations between luminescent properties of materials and their structure and morphology. In final stage of the project, the composite PiG materials (Phosphor in Glass) will be prepared and characterized as thin plates suitable for direct application onto excitation LED chip. A LED diode emitting white light/warm white light will be contracted using the LED chip with suitable excitation wavelength in the NUV spectral range and prepared PiG composite with optimised thickness, so that optimal emission characteristic will be achieved.

Coordinator: Ing. Branislav Hruška, PhD
Dates: 2019 -2021

Abstract: Conservators, archaeologists, scientists should pay attention on activities aimed at the best protection and the longest existence of historical objects. Each material is subject to gradual degradation, and even in museum conditions, historical objects are exposed to corrosion. For studying historical glasses, only nondestructive research methods such as Raman spectroscopy and optical microscopy should be considered. This unique method of analysis would result in deeper understanding of the mechanism of corrosion of historical glasses and will contribute to optimization of conservation methods.

Coordinator: Prof. Dušan Galusek, DrSc.,

Team: UACH SAV, Žilinská univerzita

Dates: 2020-2024

Abstract: Ceramic materials with eutectic microstructures have significant technological and commercial potential due to their
outstanding technological properties, and according to the latest reports, also as optically active materials
applicable in photonics and energy saving lighting. In most cases these materials are prepared by controlled
solidification of melts, which requires expensive and technologically highly demanding experimental facilities, and
high energy consumption. Our preliminary results indicate that these materials can be prepared by an alternative
method, i.e. by controlled crystallization of glass frits of relevant composition accompanied by their simultaneous
densification by pressure assisted sintering (hot pressing or spark plasma sintering). This project is aimed at
preparation of such materials in the systems RE2O3-Al2O2-(ZrO2), where RE = Y, Yb, La, also doped with
optically active rare earth elements (Er, Eu, Ce). The goal of the project is preparation of such materials with
exceptional high temperature mechanical properties, and possibly also intensive luminescnece in a broad range of
electromagnetic spectra, and identification of relations between preparation conditions, chemical composition,
microstructure, and properties of these materials. Possibility for improvement of room temperature mechanical
properties through transformation toughening related to controlled crystallization of submicron ZrO2 grains will be
investigated, and compared to materials of identical composition prepared by melt solidification.