Abstract
The interface effect of InSb quantum dots (QDs) embedded in matrix has been investigated by Raman scattering spectroscopy, x-ray diffraction (XRD), and x-ray absorption fine structure (both of EXAFS and XANES). The EXAFS and XRD results show clearly that the bond length of the Sb-In first shell of the InSb QDs contracts slightly about 0.02 Å compared with that of the bulk InSb. The Raman scattering spectrum of the InSb QDs reveals that the lattice contraction partly weakens the phonon confinement effect. The coordination geometry at the interface of the InSb QDs is mainly Sb (In)-O covalent bridge bonds. The Sb -XANES calculations of InSb QDs embedded in matrix based on FEFF8 indicate that the intensity increase and the broadening of the white line peak of Sb atoms are essentially attributed to both the increase of Sb -hole population and the change of Sb intra-atomic potential affected by the matrix. Our results show that the interface effect between the InSb QDs and the matrix leads not only to the slight lattice contraction of InSb QDs and the large structural distortion in the interface area of InSb QDs, but also to the significant change of the Sb intra-atomic potential and the obvious charge redistribution around Sb atoms.
- Received 28 December 2004
DOI:https://doi.org/10.1103/PhysRevB.72.075341
©2005 American Physical Society