CdSe nanocrystals formation in silica sonogels

Book · Sat Dec 31 04:00:00 EST 1994

OSTI ID:51630

Hummel, D C; Torriani, I L; Ramos, A Y ^[1]; Craievich, A F ^[2]; Rosa-Fox, N De La; Esquivias, L ^[3]

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1. Unicamp, Campinas (Brazil)
2. LNLS, Campinas (Brazil)
3. UCA, Puerto Real (Spain). Facultad de Ciencias

Host-matrix gels were prepared by hydrolysis of TEOS with the addition of cadmium nitrate, formamide as DCCA (drying control chemical additive) and submitted to a preselected dose of high power ultrasound. The impregnation of the dry ``sonogel`` with KSeCN solution under vacuum conditions promoted the formation of the CdSe nanocrystals and enhanced the mechanical properties of the matrix. A transparent red xerogel was obtained and characterized by optical spectroscopy, TEM and SAXS measurements. The results support a structural model of a porous matrix containing CdSe nanocrystals exhibiting a bimodal size distribution that depends on the Se content of the impregnating solutions. The blue shift of the optical absorption bands reveal the quantum-size confinement effects of CdSe nanocrystals.

• OSTI ID: 51630
• Report Number(s): CONF-940411--; ISBN 1-55899-246-4
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
CADMIUM SELENIDES
COMPOSITE MATERIALS
EXPERIMENTAL DATA
OPTICAL PROPERTIES
PARTICLE SIZE
SILICA GEL
SMALL ANGLE SCATTERING
SYNTHESIS
TRANSMISSION ELECTRON MICROSCOPY