Abstract
We have studied the transition from two- to three-dimensional (3D) growth during migration enhanced epitaxy (MEE) of CdSe on ZnSe by systematically varying the CdSe thickness. Transmission electron microscopy (TEM) images show structures that contain islands within the quantum well (QW) region when the CdSe exceeds a critical thickness. The transition to a 3D interface could be confirmed by high-resolution X-ray diffraction (HRXRD) measurements. (0 0 4) diffraction profiles could be simulated assuming flat interfaces only for CdSe below the critical thickness. Photolumine-scence (PL) shows emission energies up to 2.7 eV for flat QWs while samples with CdSe layers above the critical thickness show a broad emission around 2.3 eV. Photoluminescence excitation (PLE) measurements from the latter samples support the assumption that CdSe islands within the QW region act as a final centre of recombination. Heterostructures containing a CdTe or a ZnTe layer have been investigated for comparison.
Original language | English (US) |
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Pages (from-to) | 259-263 |
Number of pages | 5 |
Journal | Journal of Crystal Growth |
Volume | 184-185 |
DOIs | |
State | Published - 1998 |
Externally published | Yes |
Keywords
- HRXRD
- II-VI semiconductors
- MBE
- PL
- Quantum dots
- TEM
ASJC Scopus subject areas
- Condensed Matter Physics
- Inorganic Chemistry
- Materials Chemistry