Highly Luminescent CdTe Nanocrystals Synthesized in Aqueous Solution and Self-Assembled on Polyelectrolyte Multilayers
CdTe nanocrystals have been synthesized in aqueous solution at 92oC under open-air conditions. During the reaction, aliquots of the samples were taken at different growth times and used to obtain their UV-Vis absorbance and photoluminescence spectra in order to estimate the nanocrystal size. The absorption peaks are located around 459 nm for 1 h, 478 nm for 2 h, 491 nm for 4 h, 532 nm for 7 h and 610 nm for 94 h of growth time. The mean nanocrystal size for these samples is 2 nm, 2.2 nm, 2.3 nm, 2.6 nm and 3.4 nm, respectively, according to the theoretical calculations of 1s1/2 – 1s3/2 excitonic transition. Finally, CdTe nanocrystals were assembled using layer-by-layer technique on glass substrates, using PDDA as cationic polyelectrolyte and negatively charged CdTe nanocrystals. The Raman spectroscopy shows that CdTe nanocrystals preserve the nanoparticle properties after being assembled.
Luís Guerra ROSA and Fernanda MARGARIDO
C.D. Gutiérrez-Lazos et al., "Highly Luminescent CdTe Nanocrystals Synthesized in Aqueous Solution and Self-Assembled on Polyelectrolyte Multilayers", Materials Science Forum, Vols. 636-637, pp. 374-379, 2010