Tight-binding studies of surface effects on electronic structure of CdSe nanocrystals: the role of organic ligands, surface reconstruction, and inorganic capping shells

Surface Modification of CdSe and CdS Quantum Dots-Experimental and Density Function Theory Investigation

“…[56]. More sophisticated models of capping QDs have represented the QD core through the bulk atoms using semiempirical tight-binding [57] and pseudopotential [58] approaches, while the passivating molecules have been modeled through either single oxygen atoms or simplified model potentials [59]. Any realistic model, however, has to explicitly describe bonding between the QD and the ligands, which is lacking from the approaches mentioned above.…”

Experimental Observation of Quantum Confinement in the Conduction Band of CdSe Quantum Dots

“…[3] Hence, CdSe represents an archetypal system for numerous QD applications (including uses in biomedical imaging and laser diodes) and an ideal model for the study of quantum confinement effects. Although extensive research has been devoted to characterization of the electronic structure in CdSe QDs, [4][5][6][7][8][9] the sizedependent evolution of the valence band (VB) and CB-DOS remain unresolved from one another via experimental study. It has been demonstrated that theoretical calculations provide a means for the deconvolution and isolated study of the VB and CB.…”

X-ray and photoelectron spectroscopy of the structure, reactivity, and electronic structure of semiconductor nanocrystals

“…It is very probable that bond lengths and angles deviate from the idealized bulk values throughout the whole particle, with the largest displacements occurring at the surface. Tightbinding calculations which minimize the total energy by moving all the atoms in the nanocrystal show that the perturbations are indeed similar to bulk reconstructions and are the largest on the surface [37,38]. But lacking an appropriate model to account for internal rearrangements, we only state here that the observed broadening of XANES spectra can be related to structural disorder within the nanocrystals, which is believed to be largely due to atomic displacements at the surface.…”