Eur. Phys. J. B 53, 35-38 (2006)
https://doi.org/10.1140/epjb/e2006-00350-3

Electronic properties of multi-quantum dot structures in Cd _1-xZn _xS alloy semiconductors

¹ Laboratoire de Physique des Semi-conducteurs et des Composants Électroniques, Faculté des Sciences, Avenue de l'environnement, 5000 Monastir, Tunisia
² Unité de Physique Quantique, Faculté des Sciences, Avenue de l'environnement, 5000 Monastir, Tunisia
³ École Préparatoire aux Académies Militaires, Avenue Maréchal Tito, 4029 Sousse, Tunisia

Corresponding author: ^a saftanabil@yahoo.fr

Received: 6 March 2006
Revised: 23 May 2006
Published online: 22 September 2006

Abstract

In this paper, we present a theoretical study of the quantized electronic states in Cd_1-xZn_xS quantum dots. The shape of the confining potential, the subband energies and their eigen envelope wave functions are calculated by solving a one-dimensional Schrödinger equation. Electrons and holes are assumed to be confined in dots having a flattened cylindrical geometry with a finite barrier height at the boundary. Optical absorption measurements are used to fit the bandgap edge of the Cd_1-xZn_xS nanocrystals. An analysis of the electron band parameters has been made as a function of Zn composition. Two main features were revealed: (i) a multiplicity in Cd_1-xZn_xS quantum dots with different crystalline sizes has been found to fit accurately experimental data in the composition range 0 ≤x ≤0.2; (ii) the fit did not, however, show a multiplicity for x higher than 0.4. On the other hand, we have calculated the energy level structure of coupled Cd_1-xZn_xS semiconductor quantum dots using the tight-binding approximation. As is found the Zn composition x = 0.4 is expected to be the most favorable to give rise a superlattice behavior for the Cd_1-xZn_xS quantum dots studied.