Res. Chem. Intermed.
, Vol. 28, No. 7–9, pp. 847–856 (2002)
Also available online - www.vsppub.com
Tuning the properties of CdSe nanoparticles in reverse
NIRMALA CHANDRASEKHARAN and PRASHANT V. KAMAT
Notre Dame Radiation Laboratory, Notre Dame, Indiana 46556-0579,
Abstract—A new and simple approach of synthesizing size-quantized CdSe colloids in reverse
micellar suspension is described. The room temperature reaction between Cd
and selenosulfate is
carried out within the water pool of di-octyl sulphosuccinate (Aerosol-OT) reverse micelles. The size
dependent absorption and emission properties of these small CdSe particles (3– 5 nm) are described.
The Q-sized CdSe nanoparticles exhibit an emission yield of 0.13. Up to a factor of two enhancement
in the emission ef ciency can be achieved following the surface functionalization of CdSe colloids
with triethyl amine.
: Semiconductor nanoparticles; size quantization effect; reverse micelles; emission; CdSe.
Reverse micelles provide a controlled environment to synthesize extremely small
particles of the order of the excitonic diameter and stabilize them against further
growth. Reverse micelles are thermodynamically stable structures, which consist of
a nanometer sized spherical water core that is encapsulated by surfactant molecules
in a non-polar medium. They have been used to synthesize semiconductors,
metals and other inorganic crystallites [1– 3]. Dioctyl sulphosuccinate (Aerosol-OT,
AOT) is commonly used as the surfactant since reverse micelles formed using this
surfactant consist of well de ned droplets. The micellar structures have been well
studied and it has been experimentally shown using small-angle neutron-scattering
(SANS) and photon correlation spectroscopy that the size of the water pool depends
on the molar water-to-surfactant ratio
O]/[AOT] [4, 5]. There are several
reports in literature that demonstrate the usefulness of reverse micelles in stabilizing
semiconductor colloids in organic media. (See for example, Refs [6–10].)
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