Disorder effect upon energy band gaps and carrier effective masses of ZnxCd1−xS
Laboratory of Materials Physics and its Applications, Physics Department, Faculty of Science, University of M’sila, 28000, M’sila, Algeria
2 Laboratoire de Physique de la Matière Condensée (LPMC), Département de Physique, Faculté des Sciences de Tunis, Université Tunis El Manar, 2092, Tunis, Tunisia
Accepted: 4 May 2021
Published online: 6 July 2021
The influence of compositional disorder on ZnxCd1−xS energy band gaps and carrier effective masses has been investigated. The calculations are performed using a pseudopotential approach under the virtual crystal approximation (VCA). A correction to the VCA has been introduced so as to take into consideration the disorder effect. Our results show that the theoretical model used in the present contribution should include the disorder effect in order to describe more accurately the fundamental band gap bowing parameter of the experimental dependence. However, the disorder effect upon electron, light-hole and heavy-hole effective masses in the material system of interest is shown to be weak. Moreover, the trend of the conduction Г, X and L valleys and the nature of the optical fundamental band gap are found to be weakly altered by the alloy disorder. The different photo-catalytic activity of wurtzite and zinc-blende CdS is discussed for a new understanding.
© The Author(s), under exclusive licence to Società Italiana di Fisica and Springer-Verlag GmbH Germany, part of Springer Nature 2021