Nanocomposites and nanomaterials

Luminescence properties of Gd3Ga5O12: Tb3+ nanocrystals dispersed in a polymer matrix
A. Luchechko1*, O. Tsvetkova1, L. Kostyk1, S. Varvarenko2, R. Lys1
1 Department of Sensor and Semiconductor Electronics, Ivan Franko National University of Lviv, Tarnavskogo St.107, 79017 Lviv, Ukraine.
E-mail: luchechko@electronics.lnu.edu.ua
2 Department of Organic Chemistry, National University “Lvivska Politechnika”,
Bandera St. 12, 79013 Lviv, Ukraine.

Rare-earth doped garnets have attracted much attention as an important material for application in photonics first of all as active optical materials or biomarkers [1]. The trivalent terbium ion (Tb3+) is an important dopant for green phosphors [2]. At the same time, nanostructured materials are considered to be very prospective for the much technological application [1,2]. The obtaining of transparent and low-scattering nanocomposites with high luminescence efficiency is also an important area of research.
The aim of this work was to investigate structural and luminescent properties of polymer nanocomposite material containing Gd3Ga5O12: Tb3+ nanocrystals embedded into the polymer matrix. Gadolinium gallium garnet nanocrystals doped with Tb3+ ions with a concentration of 1.0 mol% were synthesized via the co-precipitation method. Prepared Gd3Ga5O12: Tb3+ polymer nanocomposites were characterized using scanning electron microscope (SEM), atomic force microscopy (AFM), photoluminescence excitation (PLE) and PL emission spectra.
The nanocomposites exhibit characteristic green emission related to the f-f transitions of Tb3+ ions with the main line at 546 nm. The observed intensity is quite high and suggests successful encapsulation of Tb3+ doped nanocrystals in the polymer. The optimized polymer matrix for obtaining of enhanced PL emission of this nanocrystals was found. The effect of the polymer composition on the structural and optical-luminescence properties is discussed.

1.	Speghini A., Piccinelli F., Bettinelli M. Synthesis, characterization and luminescence spectroscopy of oxide nanopowders activated with trivalent lanthanide ions: The garnet family // Optical Materials.-2011.-33.-P. 247-257. 
2.	Luchechko A, Kostyk L. et al. Green-emitting Gd3Ga5O12: Tb3+ nanoparticles phosphor: synthesis, structure, and luminescence // Nanoscale Research Letters. -2017. -12:263. -P. 1-6.