Punctuated island growth: An approach to examination and control of quantum dot density, size, and shape evolution

The later stages of the evolution of epitaxical island quantum dots are examined systematically for InAs depositions on GaAs(001) following the conventional continuous deposition mode and an approach introduced here called punctuated island growth (PIG). The comparative study provides clear structural and optical evidence for a change in InAs island shape at a self-limiting lateral size, first reached for depositions similar to 2 ML. The PIG approach has also allowed realization of the narrowest reported inhomogeneous linewidth of 23 meV for low temperature photoluminescence from a single layer of binary InAs/GaAs quantum dots. (C) 1999 American Institute of Physics. [S0003-6951(99)01627-7].