Band structures of laterally
coupled quantum dots, accounting for electromechanical effects
Prabhakar, S., Melnik, R., Patil,
S.
Journal of Physics: Conference Series (Quantum Dot 2010, Proceedings,
Nottingham, UK), 245, Art. 012014, 1--4, 2010
Abstract:
In a series of recent papers we demonstrated that coupled
electro-mechanical effects can lead to pronounced contributions in band
structure calculations of low dimensional semiconductor nanostructures (LDSNs)
such as quantum dots, wires, and even wells. Some such effects are essentially
nonlinear. Both strain and piezoelectric effects have been used as tuning
parameters for the optical response of LDSNs in photonics, band gap engineering
and other applications. However, these effects have been largely neglected in
literature while laterally coupled quantum dots (QDs) have been studied. The
superposition of electron wave functions in these QDs become important in the
design of optoelectronic devices as well in tayloring properties of QDs in other
applications areas. At the same time, laterally grown QDs coupled with electric
and mechanical fields are becoming increasingly important in many applications
of LDSN-based systems, in particular where the tunneling of electron wave
function through wetting layer (WL) becomes important and the distance between
the dots is treated as a tuning parameter. Indeed, as electric and elastic
effects are often significant in LDSNs, it is reasonable to expect that the
separation between the QDs may also be used as a tuning parameter in the
application of logic devices, for example, OR gates, AND gates and others. In
this contribution, by using the fully coupled model of electroelasticity, we
build on our previous results while analyzing the influence of these effects on
optoelectronic properties of QDs. Results are reported for III-V type
semiconductors with a major focus given to GaN/AlN based QD systems.
Keywords: arrays of quantum dots, lateral coupling,
electromechanical effects, wetting layer, fully coupled models.