resumo
Eu(3+)-Doped CdS hexagonal nanocrystals (NCs), with an average size of similar to 4 nm, have been prepared through a simple methodology based on the direct precipitation of CdS NCs using 1-thioglycerol as a capping molecule. Steady-state and time-resolved photoluminescence studies (14-300 K) reveal an effective CdS NCs-to-Eu(3+) energy transfer process involving surface localized states and mediated by a thermally activated exchange mechanism. Furthermore, the analysis of the optical data also points out the presence of two distinct Eu(3+) local coordination sites with different relaxation kinetics and attributed to lattice-bound and surface-bound centres. The (5)D(0) lifetime values are longer than those reported previously for sol-gel derived Eu(3+)-doped CdS NCs.
palavras-chave
CADMIUM SELENIDE NANOCRYSTALS; LIGHT-EMITTING-DIODES; POLYMER SOLAR-CELLS; SEMICONDUCTOR NANOCRYSTALS; PHOTOPHYSICAL PROPERTIES; CORE/SHELL NANOCRYSTALS; ENHANCED FLUORESCENCE; US NANOCRYSTALS; GEL SYNTHESIS; EU3+ IONS
categoria
Chemistry; Materials Science
autores
Planelles-Arago, J; Cordoncillo, E; Ferreira, RAS; Carlos, LD; Escribano, P
nossos autores
Luís Carlos
Professor Catedrático
Maria Rute de Amorim e Sá Ferreira André
Professor Catedráticoagradecimentos
This research was supported by the Spanish Government (MAT-2008-03479) and Bancaixa Foundation-Universitat Jaume I (P1 1B2007-47) projects. J. Planelles-Arago specially thanks Spanish Ministerio de Ciencia e Innovacion for a FPU fellowship.