GROWTH-KINETICS AND OPTICAL-PROPERTIES OF SELF-ORGANIZED GAN QUANTUM DOTS

Self-organized GaN islands of nanometric scale were fabricated by cont rolling the Stranski-Krastanov growth mode of GaN deposited by molecul ar beam epitaxy on AlN. Evidence for ripening of dots under vacuum has been observed, resulting in changes in dot size distribution. We also show that in superlattice samples, consisting of multiple layers of G aN islands separated by Aln, the GaN islands are vertically correlated provided that the AlN layer thickness remains small enough. The lumin escence peak of GaN dots is blueshifted with respect to bulk emission and its intensity does not vary with temperature, both effects demonst rating the strongly zero-dimensional character of these nanostructures . (C) 1998 American Institute of Physics..