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 exa mined systematically for InAs depositions on GaAs(001) following the conven tional continuous deposition mode and an approach introduced here called pu nctuated island growth (PIG). The comparative study provides clear structur al and optical evidence for a change in InAs island shape at a self-limitin g lateral size, first reached for depositions similar to 2 ML. The PIG appr oach has also allowed realization of the narrowest reported inhomogeneous l inewidth of 23 meV for low temperature photoluminescence from a single laye r of binary InAs/GaAs quantum dots. (C) 1999 American Institute of Physics. [S0003-6951(99)01627-7].