PERSONAL DE APOYO
MARCHI Maria Claudia
congresos y reuniones científicas
Título:
TUNED PHOTOLUMINESCENCE EMISSION OF CDS DOTS EMBEDDED IN MESOPOROUS SILICA
Autor/es:
V. DELLA SAVIA, M.C. MARCHI, E. OTAL, G. SOLER-ILLIA, S.ALDABE BILMES
Lugar:
Strasbourg, Francia
Reunión:
Congreso; E-MRS 2005 Spring Meeting; 2005
Institución organizadora:
e-mrs
Resumen:
Mesoporous silica films
synthesised with different surfactants are used as templates for
nucleation and growth of CdS nanoparticles by impregnation in aqueous
Cd2+ and S2- solutions. The presence of crystalline CdS nanoparticles
within the silica matrix was confirmed by DRX and TEM/SAD/EDS. The
photoluminescence emission of CdS in these composites exhibits a narrow
excitonic band at ca. 2.6 eV and a broad band in the 2.2-1.9 eV range
due to radiative decay of excited surface states. The emission of CdS
dots in these silica films is stable for several months. Effects in the
position and relative intensity of the excitonic and surface state bands
are observed when the mesoporous film is synthesised with CTAB, F127 or
Brij 58. CdS nanoparticles included within mesoporous films obtained
with CTAB show higher excitonic emission as the CTAB/Si ratio in the
precursor silica sol decreases. The main conclusion of this work is that
the blue emission of CdS dots can be enhanced by quenching the emission
of surface states with appropriate control of the chemistry of the
inorganic walls interacting with CdS nanoparticles.