Ab initio calculations of structural and electronic properties of CdTe clusters

TL;DR

This study uses ab initio density functional calculations to analyze the structural and electronic properties of small CdTe clusters, revealing how composition and symmetry influence their electronic gaps and geometries.

Contribution

It provides detailed ab initio insights into the geometry, electronic structure, and symmetry effects of small CdTe clusters, including non-stoichiometric ones, which were not extensively studied before.

Findings

Cd rich clusters change symmetry upon relaxation

HOMO-LUMO gap develops in Cd rich clusters after relaxation

Symmetry influences the HOMO-LUMO gap in clusters

Abstract

We present results of a study of small stoichiometric $Cd_{n}Te_{n}$ ($1{\leq}n{\leq}6$) clusters and few medium sized non-stoichiometric $Cd_{m}Te_{n}$ [($m,n= 13, 16, 19$); ($m{\neq}n$)] clusters using the Density Functional formalism and projector augmented wave method within the generalized gradient approximation. Structural properties {\it viz.} geometry, bond length, symmetry and electronic properties like HOMO-LUMO gap, binding energy, ionization potential and nature of bonding {\it etc.} have been analyzed. Medium sized non-stoichiometric clusters were considered as fragments of the bulk with T{$_{d}$} symmetry. It was observed that upon relaxation, the symmetry changes for the Cd rich clusters whereas the Te rich clusters retain their symmetry. The Cd rich clusters develop a HOMO-LUMO gap due to relaxation whereas there is no change in the HOMO-LUMO gap of the Te rich clusters. Thus, the symmetry of a cluster seems to be an important factor in determining the HOMO-LUMO gap.