Radiative electron-hole recombination and degradation processes in thiol-stabilized CdTe nanocrystals

Viktor V. Strelchuk 1Peter Feychuk 2Larysa P. Shcherbak 2Maksym Kovalenko 2Vadim P. Bryksa 1Alexander F. Kolomys 1Sergiy G. Krylyuk 1Dmytro V. Korbutyak 2Mykhailo Valakh 1

1. Institute of Semiconductor Physics NAS Ukraine, Kyiv, Ukraine
2. Chernivtsi National University (ChNU), 2 Kotsubinsky Str., Chernivtsi 58012, Ukraine


Cadmium telluride nanocrystals (NCs) synthesized by wet chemical routes are very promising objects for various applications including opto- and nanoelectronic devices and biological labeling. However, many of their properties which define the applicability of the NCs, such as radiative recombination pathways, degradation processes, etc., are not fully understood yet.
In this contribution, we report on the synthesis and photoluminescence (PL) investigations of CdTe NCs synthesized in aqueous solution and stabilized with thioglycolic acid. The PL spectra were recorded for the temperature range 5 ? 300 K using different lines of an Ar+-laser for excitation.
Room temperature PL spectra of the NCs consisted of an intensive line due to near-edge recombination and a weak low-energy tail connected with the recombination via deep traps. Depending on the synthesis parameters, the maximum position could vary during the solution storage at room temperature in dark. For some samples, freezing of the solution containing NCs resulted in a red-shift of the PL maximum. After that the energy position of the PL line followed the temperature dependence of the CdTe band gap. We suggest that such an unusual behavior is caused by changes in the passivation conditions at solution freezing. Low-temperature PL spectra measured at different excitation energies clearly showed that the main PL line consists of several components. To explain the observed features, a model which accounts for both the near-edge recombination and the recombination via the states created by the cadmium ? thiol and tellurium ? OH complexes at the surface is proposed.

Legal notice
  • Legal notice:

    Copyright (c) Pielaszek Research, all rights reserved.
    The above materials, including auxiliary resources, are subject to Publisher's copyright and the Author(s) intellectual rights. Without limiting Author(s) rights under respective Copyright Transfer Agreement, no part of the above documents may be reproduced without the express written permission of Pielaszek Research, the Publisher. Express permission from the Author(s) is required to use the above materials for academic purposes, such as lectures or scientific presentations.
    In every case, proper references including Author(s) name(s) and URL of this webpage: http://science24.com/paper/1833 must be provided.


Related papers
  1. Confocal Raman microscopy of the strain AlGaN/GaN heterostructures on sapphire
  2. Probing the structure of core-shell nanoparticles by resonant Raman scattering spectroscopy
  3. Interdiffusion Processes in Self-Organization of Quantum Dot Nanostructures: Raman Scattering and AFM-Investigtion
  4. High-temperature electrical properties of CdTe<Pb> crystals under Te saturation
  5. The influence of thermal treatment on the properties of CdTe colloidal nano-solutions stabilized by thioglycolic acid
  6. Laser stimulated p-n junction formation in CdTe
  7. Cd1-xZnxTe Single Crystals Growth from Vapor Phase
  8. Nanocrystals of CdTe and CdMnTe: Growth, Optical and Magnetooptical Properties

Presentation: poster at E-MRS Fall Meeting 2004, Symposium G, by Viktor V. Strelchuk
See On-line Journal of E-MRS Fall Meeting 2004

Submitted: 2004-04-29 10:22
Revised:   2009-06-08 12:55
Web science24.com
© 1998-2021 pielaszek research, all rights reserved Powered by the Conference Engine