Shape transformations of partially capped self-assembled InAs quantum dots grown on InP are studied. Atomic force microscopy images show large anisotropic redistribution of the island material after coverage by a 1 nm thick InP layer. The anisotropic material redistribution occurs within a few minutes and leads to a change from lens-like to elongated ring-like islands. The shape transformation is not accompanied by dot material compositional change. The formation of InAs/InP quantum rings disagrees with a previous model of InAs/GaAs ring formation that assumes that the driving force for the dot to ring transformation is the difference in surface diffusion velocity of indium and gallium atoms.
@article{arxiv.cond-mat/0210631,
title = {Formation of InAs Self-Assembled Quantum Rings on InP},
author = {T. Raz and D. Ritter and G. Bahir},
journal= {arXiv preprint arXiv:cond-mat/0210631},
year = {2009}
}
Comments
13 pages, including 2 figures and 1 table. Submitted to Appl. Phys. Lett