The influence of thermal treatment on the properties of CdTe colloidal nano-solutions stabilized by thioglycolic acid

Peter Feychuk 2Shcherbak Laryssa 2Khalavka Yuriy 2Bernhard Mingler 1Gernot Friedbacher 3

1. University of Vienna, Institute of Materials Physics, Wien, Austria
2. Chernivtsi National University (ChNU), 2 Kotsubinsky Str., Chernivtsi 58012, Ukraine
3. Vienna Technical University, 9, Getreidemarkt, Wien 1040, Austria

Abstract


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+: Te2-: 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.

 

Related papers
  1. High-temperature electrical properties of CdTe<Pb> crystals under Te saturation
  2. Radiative electron-hole recombination and degradation processes in thiol-stabilized CdTe nanocrystals
  3. Laser stimulated p-n junction formation in CdTe
  4. Cd1-xZnxTe Single Crystals Growth from Vapor Phase

Presentation: poster at E-MRS Fall Meeting 2005, Symposium B, by Peter Feychuk
See On-line Journal of E-MRS Fall Meeting 2005

Submitted: 2005-06-04 06:16
Revised:   2009-06-07 00:44