  Epitaxially-grown semiconductor quantum dots (QDs) provide an attractive
platform for the development of deterministic sources of high-quality quantum
states of light. Such non-classical light sources are essential for quantum
information processing and quantum communication. QDs emitting in the telecom
wavelengths are especially important for ensuring compatibility with optical
fiber systems required to implement quantum communication networks. To this
end, GaSb QDs fabricated by filling local-droplet etched nanoholes are emerging
as a viable approach, yet the electronic properties of such nanostructures have
not been studied in detail. In this article, an insight into the electronic
structure and carrier dynamics in GaSb/AlGaSb QDs is provided through a
systematic experimental analysis of their temperature-dependent
photoluminescence behavior. A steady-state rate equation model is used to
reveal the relevant energy barriers for thermally activated carrier capture and
escape processes. Furthermore, results of detailed theoretical simulations of
quantum-confined energy states using the multi-band k.p model and the effective
mass method are presented. The purpose of the simulations is to reveal the
direct and indirect energy states, carrier wavefunctions, and allowed optical
transitions for GaSb QDs with different physical dimensions.
