Size quantization patterns in self-assembled InAs/GaAs quantum dots

✍ Scribed by M. Colocci; F. Bogani; L. Carraresi; R. Mattolini; A. Bosacchi; S. Franchi; P. Frigeri; S. Taddei; M. Rosa-Clot

• Publisher: Elsevier Science
• Year: 1997
• Tongue: English
• Weight: 136 KB
• Volume: 22
• Category: Article
• ISSN: 0749-6036
• DOI: 10.1006/spmi.1996.0351

✦ Synopsis

Molecular beam epitaxy has been used for growing self-assembled InAs quantum dots. A continuous variation of the InAs average coverage across the sample has been obtained by properly aligning the (001) GaAs substrate with respect to the molecular beam. Excitation of a large number of dots (laser spot diameter ≈100 µm) results in structured photoluminescence spectra; a clear quantization of the dot sizes is deduced from the distinct luminescence bands separated in energy by an average spacing of 20-30 meV. We ascribe the individual bands of the photoluminescence spectrum after low excitation to families of dots with roughly the same diameter and heights differing by one monolayer.