ABSTRACT
Self-organized GaSh quantum dots grown by metal-organic chemical vapour deposition are investigated by Transmission electron microscopy with respect to their structural peculiarities depending on the amount of deposited GaSh. The average size of quantum dots increases with increasing GaSh deposition. Defects were found in quantum dots having a lateral size larger than 25 nm. GaSh quantum dots (QD) were deposited on (001)-oriented GaAs substrate by means of metalorganic chemical vapour deposition. The QDs form via self-organization due to strain relaxation. Since the structures have a lateral size of a few nanometers, quantum mechanical effects have a great influence on optical and electronic properties of this materials system. In order to investigate the growth-correlated properties of the QDs, the deposited amount of GaSh was varied for a series of samples between nominal thicknesses of 3.6 and 5.8 monolayers. Some quantum dots have shown a circular defect which could be identified as a dislocation loop.
