First-principles study of structural stability and electronic structure of CdS nanoclusters

Using first-principles density functional calculations, we have studied the structural stability of stoichiometric as well as nonstoichiometric CdS natioclusters at ambient pressure with diameters ranging up to about 2.5 nm. Our study reveals that the relative stability of the two available structures for CdS, namely zincblende and wurtzite, depends sensitively on the details like surface geometry and/or surface chemistry. The associated band gap also exhibits nonmonotonic behavior as a function of cluster size. Our findings may shed light on reports of experimentally observed structures and associated electronic structures of CdS nanoclusters found in the literature.