Title Synthesis, structural, and optical characteristics of gdpo4:ln3+ (ln3+ = ce3+, tb3+, eu3+) nanoparticles /
Translation of Title GdPO4:Ln3+ (Ln3+ = Ce3+, Tb3+, Eu3+) nanodalelių sintezė, struktūrinių ir optinių savybių tyrimas.
Authors Ežerskytė, Eglė
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Pages 63
Keywords [eng] phosphates, nanoparticles, cerium, europium, terbium, gadolinium, luminescence, anti-counterfeit pigments, bioimaging
Abstract [eng] This master thesis describes synthesis of GdPO4 NPs doped with lone Ce3+, Tb3+, or Eu3+ ions and their various combinations following structural and spectroscopic investigation of the produced samples regarding the evaluation of such phosphors as anti-counterfeit pigments or bioimaging agents. Hydrothermal synthesis route was chosen to produce all the samples for this research. XRD analysis assured that materials with trigonal crystal structure were synthesized and no phase impurities were detected. SEM images revealed that particles formed were of nanoscale dimensions. Optical properties of GdPO4 NPs doped with lone Ce3+, Tb3+, or Eu3+ ions or their various combinations were examined via recording excitation and emission spectra, PL decay curves and temperature-dependent excitation, emission spectra, and PL decay curves. The obtained measurement data was used to evaluate the efficiency of ET processeses, average PL lifetime values, CIE 1931 color space coordinates, TQ1/2 and Ea values of produced phosphors. GdPO4:Ce3+/Tb3+/Eu3+ samples demonstrated a typical emission spectra in near UV, green, and red spectral range, respectively. ET efficiency values of GdPO4:Ce3+,Tb3+ and GdPO4:Tb3+,Eu3+ NPs reached up to 99% and 95%, respectively. The emission spectra of phosphates doped with Ce3+/Eu3+ pair or Ce3+/Tb3+/Eu3+ triplet was strongly quenched due to CT process between Ce3+ and Eu3+ ions. The analysis of the obtained results suggests that Ce3+/Tb3+, or Tb3+/Eu3+ pair doped GdPO4 phosphors could be further examined as a potential anti-counterfeit pigment and singly Eu3+, or Tb3+/Eu3+ pair doped NPs are valid candidates for multimodal bioimaging.
Dissertation Institution Vilniaus universitetas.
Type Master thesis
Language English
Publication date 2022