CdTe nanoparticles are characterized by high luminescence quantum yield. In CdTe nanocrystals synthesized by metal-organic technologies this factor is near to 65% at room temperature. But the use of such materials is complicated by their luminescence instability at air. On the other side recently essential progress in CdTe nanocrystal growth in water solutions is observed. Surface modification procedures were developed as well as new properties’ investigation methods. Luminescent CdTe nanoparticles stabilized by thiol compounds are used in light-emitting arrangements and photon structures and core-nucleus structures.
The investigation and optimization of semiconductor nanoparticles synthesis is an important problem. Preliminary research shows that CdTe nanoparticles solution thermal treatment improves their stability and particles size homogeneity. Prolonged thermal treatment at 100⁰C results in edge absorption batochromic shift and amelioration of particles size uniformity owing to the Oswald ripening process.
The aim of this research was to compare the results of different thermal treating procedures in the 50 – 100⁰C temperature range on the CdTe colloidal particles’ size, stability and optical properties.
The solutions were prepared using a Cd²⁺: Te^2-: RSH = 1:0.5:2.4 molar concentration ratio. During the synthesis the pH value was equal to 11.2. The CdTe nanoparticles’ sizes were defined from absorption spectra as well as from AFM and TEM measurements.
The investigations show an essential improvement of the colloidal solutions stability. Thermal treatment at 50⁰C allows to obtain nanoparticles with a uniform 7 nm size.