Giant Excitonic Zeeman Splittings in Colloidal Co2+-Doped ZnSe Quantum Dots
Citations Over TimeTop 10% of 2006 papers
Abstract
Colloidal Co(2+):ZnSe diluted magnetic semiconductor quantum dots (DMS-QDs) were prepared by the hot injection method and studied spectroscopically. Ligand-field electronic absorption and magnetic circular dichroism (MCD) spectra confirm homogeneous substitutional speciation of Co(2+) in the ZnSe QDs. Absorption spectra collected at various times throughout the syntheses reveal that dopants are absent from the central cores of the QDs but are incorporated at a constant concentration during nanocrystal growth. The undoped cores are associated with dopant exclusion from the ZnSe critical nuclei. Analysis of low-temperature electronic absorption and MCD spectra revealed excitonic Zeeman splitting energies (DeltaE(Zeeman)) of these Co(2+):ZnSe QDs that were substantially smaller than anticipated from bulk Co(2+):ZnSe data. This reduction in DeltaE(Zeeman) is explained quantitatively by the absence of dopants from the QD cores, where dopant-exciton overlap would be greatest. Since dopant exclusion from nucleation appears to be a general phenomenon for DMS-QDs grown by direct chemical methods, we propose that DeltaE(Zeeman) will always be smaller in colloidal DMS-QDs grown by such methods than in the corresponding bulk materials.
Related Papers
- → Zeeman effect in sulfur monoxide(2017)7 cited
- → Nonlinear Zeeman splitting of nitric oxide spectral lines in magnetic field(2007)5 cited
- → On the nonlinearity of the Zeeman effect of NO in the moderate field by intracavity laser magnetic resonance at 1842 cm−1(2000)5 cited
- → Low-field Zeeman effect of the microwave spectrum of the OH radical(1967)6 cited
- → Z(1991)