Time-resolved radiative recombination measurements on GaSb quantum dot
s have been performed. The GaSb quantum dots are grown by molecular be
am epitaxy on (100) GaAs through a self-assembly process. Time-resolve
d measurements show that, after a rapid hole capture process, the phot
oluminescence decays with a fast and a slow component. The fast compon
ent is shortened significantly with higher excitation intensity while
the slow component is roughly constant. The radiative lifetimes are mu
ch longer than the lifetimes of ordinary GaSb quantum wells with a str
addling band lineup. These results support a staggered band lineup and
space charge induced band-bending model. (C) 1996 American Institute
of Physics.