Nanocomposites and nanomaterials

Thermosensitivity of the photoluminescent composites on the base of quantum dots
D. Vorontsov1, V. Dědič2, J. Valenta2, G. Okrepka3, Y. Khalavka1
1 Institute of Biology, Chemistry and Bioresources, Yuriy Fedkovych Chernivtsi National University, 2 Kotsjubynskyi St., Chernivtsi, 58012, Ukraine.
E-mail: levvoron1@gmail.com
2 Institute of Physics, Charles University, Ke Karlovu 5, Prague, 121 16, Czech Republic.
3 Bukovinian state medical university, 2, Theatralna sq., Chernivtsi, 58012, Ukraine.

Last time the nanoparticles of the semiconductors find more and more applications in different branches of technique due to quanyum confinement effect. One of such important parameter that allow to use quantum dots as photoluminescent thermometers [1].
In this work we have investigated and compared temperature dependence of the optical properties of CdTe/CdS nanoparticles incorporated in KBr and KH2PO4 (KDP) matrices in the range 125-300 K. Nanoparticles of CdTe/CdS were synthesed in a water by wet chemical method with a stabilizer thioglycolic acid with average diameter 3.6 nm and were incorporated in matrices that have quite close values of linear thermal expansion coefficients (KBr: α=36.6-39.6•10-6 K-1, KDP: α33=44•10-6 K-1 ) via slow evaporation method.
Was shown that thermal expansion coefficient plays a key role in a thermosensitivity of such type composite [2]. Was investigated that thermosensitivity coefficients calculated from Varshni equation were 0,43 and 0,47 meV/K for KBr:CdTe/CdS and KDP:CdTe/CdS composites, respectively, that prove this theory.

1.	Kalytchuk S., Adam M., Tomanec O., Zbořil R., Gaponik N., Rogach A. Sodium Chloride Protected CdHgTe Quantum Dot Based Solid-State Near-Infrared Luminophore for Light-Emitting Devices and Luminescence Thermometry // ACS Photonics.-2017.-4, N 6.-P. 1459-1465.
2.	Doskaliuk N., Khalavka Y., Fochuk P. Influence of the shell thickness and ratio between core elements on photostability of the CdTe/CdS core/shell quantum dots embedded in a polymer matrix // Nanoscale Research Letters..-2016.-11, N 1.-P. 1-8.