Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1794226 | Journal of Crystal Growth | 2009 | 4 Pages |
Abstract
We present the growth and characterization of InAs quantum dots on AlxGa1âxAs surfaces for intersubband devices. This requires the quantum dot energy levels in the AlxGa1âxAs matrix to be above the GaAs bandedge. Using standard As4 fluxes (beam equivalent pressure 8eâ6Â Torr), inhomogeneous broadening of the quantum dot size distribution increases with increasing Al content in the AlxGa1âxAs matrix. Reducing the As4 overpressure during In deposition is found to greatly improve the size distribution of the quantum dots, while producing slightly larger dots and a reduction in the density of small dots (h<1.3Â nm). Annealing at the higher standard As4 flux for 30Â s, after the reduced As4 In deposition, produced a negligible change in the quantum dot size distribution. Utilizing surface dots on top of 30 layers of self-assembled quantum dots, the maximum quantum dot height for ground state energies above the GaAs bandedge is determined to be 2Â nm for Al0.30Ga0.7As and 3Â nm for Al0.45Ga0.55As.
Keywords
Related Topics
Physical Sciences and Engineering
Physics and Astronomy
Condensed Matter Physics
Authors
Aaron Maxwell Andrews, Pavel Klang, Remigiusz Krzyzanowski, Matthias Schramböck, Hermann Detz, Werner Schrenk, Gottfried Strasser,