ŘEZÁČOVÁ Lenka Masaryk University

Synthesis of Highly Luminescent LaF3:Ln3+/LaF3 Core/shell Nanocrystals and LaF3:Ln3+ in combination with CdTe Quantum Dots

Co-authors LUBAL Přemysl, RUNOWSKI Marcin, LIS Stefan, VANĚK Jakub

LaF3: Gd3+ 30% Ce3+ 10% Eu3+ 1% (core-shell) nanoparticles have been successfully synthesized via a co-precipitation approach. Transmission electron microscope (TEM), photoluminescence spectra (PL) and lifetime measurements were used to characterize the samples. Three organic modifiers (polyacrylic acid (PAA), ethylenediaminetetraacetic acid (EDTA), citric acid (CA)) were used to prepare surface-modified nanoparticles (e.g. PAA-modified nanoparticles ~5-6 nm). Due to the presence of Eu3+ in the structure, all samples showed a bright red luminescence (λex = 248nm). Preparation LaF3: (Gd3+ 30%, Ce3+ 10%, Eu3+ 1%) of nanoparticles conjugated with CdTe quantum dots was performed by two methods. The first method includes mixing of two products while the second method was based on the co-precipitation approach. From the measurement of dynamic light scattering (DLS), it is evident that mixing of the individual components does not lead a new product. On contrary, the product obtained by synthesis led to particles having about 140 nm in diameter. The product exhibits red (λex = 248nm) and green (λex = 340 m) luminescence due to the presence of Eu3+ ion and CdTe quantum dots. ACKNOWLEDGEMENTS: Financial support from the Ministry of Education of the Czech Republic (grant MUNI/A/0972/2013), Grant Agency of the Czech Republic (No 14-12653S, No. 13-08336S) and EU programs (ERASMUS, CEITEC CZ.1.05/1.1.0/02.0068) are acknowledged.