Self-Organized Growth of Three- Dimensional Quantum-Dot Crystals with fcc-Like Stacking and a Tunable Lattice Constant
G. Springholz,
*
V. Holy,
M. Pinczolits,
G. Bauer
The self-organization of pyramidal PbSe islands that spontaneously
form during strained-layer epitaxial growth of
PbSe/Pb1
xEuxTe (x = 0.05 to 0.1) superlattices results in the formation of
three-dimensional quantum-dot crystals. In these crystals, the dots are
arranged in a trigonal lattice with a face-centered cubic (fcc)-like
A-B-C-A-B-C vertical stacking sequence. The lattice constant of the dot
crystal can be tuned continuously by changing the superlattice period. As shown by theoretical calculations, the elastic anisotropy in these
artificial dot crystals acts in a manner similar to that of the
directed chemical bonds of crystalline solids. The narrow size
distribution and excellent control of the dot arrangement may be
advantageous for optoelectronic device applications.
G. Springholz, M. Pinczolits, G. Bauer, Institut für
Halbleiterphysik, Johannes Kepler Universität Linz, 4040 Linz,
Austria. V. Holy, Laboratory of Thin Films and Nanostructures, Faculty
of Science, Masaryk University, Kotlarska 2, 611 37 Brno, Czech
Republic.
*
To whom correspondence should be addressed. E-mail:
g.springholz{at}hlphys.uni-linz.ac.at