Article Sidebar
Article Details
The Momona Ethiopian Journal of Science accepts the manuscripts for consideration with the understanding that the manuscript has not been published and is not under consideration for publication elsewhere. Only original articles will be considered for publication if they have been published previously as abstracts, but not if they have been published previously as extended abstract (>1000 words). This applies to both electronic and print versions of the journal. The authors should assign copyright ownership to the Editorial Office of MEJS in the event that the manuscript is accepted for publication in the Momona Ethiopian Journal of Science. All accepted manuscripts must be accompanied by a copyright statement signed by all authors. A copy of the copyright form will be supplied along with the final reviewed version of the manuscript that is sent for final proof- reading. Authors may make multiple copies of the form if necessary and send to the Editorial Office with author’s signature(s) even individually.
All articles published by Momona Ethiopian Journal of Science (MEJS) are Open Access under the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0). Under this license, authors retain ownership of the copyright for their content, and anyone can copy, distribute, or reuse articles as long as the author and original source are properly cited. In all these cases for re-use, the authors will be given proper credit to the original publication in MEJS.
Main Article Content
A DFT Study on the Structural and Electronic properties of Cadmium Telluride (Cd<sub>n</sub>Te<sub>n</sub>) and Cadmium Zinc Telluride (Cd<sub>(n−m)</sub>Zn<sub>m</sub>Te<sub>n</sub>) Clusters
Abstract
In this study, the structural and electronic properties of CdnTen and Cd(n−m)ZnmTen clusters have been studied using the plane wave based density functional theory (DFT). The QUANTUM ESPRESSO/PWSCF package employing the local density approximation (LDA) for the exchange correlation potential is used. In all calculations, the geometry optimization was employed in allowing the structures to fully relax. Structural properties viz. geometry, bond length and electronic properties like HOMO-LUMO gap, binding energy, second order energy difference and nature of bonding have been analyzed. As a result, we obtained that the binding energy increases with increasing cluster size and doping level. Zinc doped CdnTen clusters show greater binding energy than the undoped clusters. Planar structures are obtained for very small cluster sizes and in our simulation three dimensional structure is found at Cd4Te4 cluster in the lowest energy geometry. Clusters of certain sizes often have special properties, i.e. higher stability or larger HOMO-LUMO gap when compared with other clusters, such as Cd(3−m)ZnmTe3, m = 0, 1, 2 clusters. Thus, we can take it as a building block in the growth of the structures in our calculation. The partial charge density distribution of the HOMO and LUMO levels for CdnTen and Cd(n−m)ZnmTen clusters show that, the HOMO levels are predominantly localized on the Te atoms and the LUMO levels are distributed on both Cd and Zn atoms. Moreover, the LUMO levels are delocalized at the center of the clusters due to the hybridization of the molecular orbitals. The LDOS and energy level plots show discrete lines at the atomic level and the discreteness disappears as the cluster size increases.
Keywords: HOMO-LUMO, Pseudopotential, Cluster, Isomer.
