Ab initio calculations of structural and electronic properties of CdTe clusters

Abstract

We present results of a study of small stoichiometric $C{d}_{n}T{e}_n$ ($1\le n\le 6$) clusters and few medium sized non-stoichiometric $C{d}_{m}T{e}_n$ [($m,n=13,16,19$); ($m\ne n$)] 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.

8 pages 16 figures

References in corpus (2)

• Evolution of the electronic structure with size in II-VI semiconductor nanocrystals
• A pseudopotential study of electron-hole excitations in colloidal, free-standing InAs quantum dots