Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
7934540 | Physica E: Low-dimensional Systems and Nanostructures | 2014 | 7 Pages |
Abstract
We apply first principles density functional and time dependent density functional computational methods to study the structures, densities of states, absorption spectra, and optical gaps of spherical ZnSe and CdTe semiconductor quantum dots in the size range 0.3-2.2Â nm. Our calculations are performed in real space without an explicit basis. The surfaces of the quantum dots are passivated with partially charged hydrogen atoms. We find that this passivation technique effectively removes the electronic states associated with the surface atoms from the gaps of ZnSe and CdTe nanocrystals, but does not affect the energies of the quantum-confined electronic states. Our study shows that the absorption gaps of ZnSe and CdTe quantum dots decrease with increasing dot diameter. The size-dependent variations of the computed optical gaps in surface-passivated ZnSe and CdTe quantum dots are found to be consistent with the effects of quantum confinement observed in group IV and group III-V semiconductor nanocrystals.
Keywords
Related Topics
Physical Sciences and Engineering
Materials Science
Electronic, Optical and Magnetic Materials
Authors
Sufian Alnemrat, Young Ho Park, Igor Vasiliev,