Growth process, characterization, and modeling of electronic properties of coupled InAsSbP nanostructures

Abstract

Quaternary III-V InAsSbP quantum dots (QDs) have been grown in the form of cooperative InAsSb/InAsP structures using a modified version of the liquid phase epitaxy. High resolution scanning electron microscopy, atomic force microscopy, and Fourier-transform infrared spectrometry were used to investigate these so-called nano-camomiles, mainly consisting of a central InAsSb QD surrounded by six InAsP-QDs, that shall be referred to as leaves in the following. The observed QDs average density ranges from 0.8 to 2 x 10(9) cm(-2), with heights and widths dimensions from 2 to 20 nm and 5 to 45 nm, respectively. The average density of the leaves is equal to (6-10) x 10(9) cm(-2) with dimensions of approx. 5 to 40 nm in width and depth. To achieve a first basic understanding of the electronic properties, we have modeled these novel nanostructures using second-order continuum elasticity theory and an eight-band k . p model to calculate the electronic structure. Our calculations found a clear localization of hole states in the central InAsSb dot. The localization of electron states, however, was found to be weak and might thus be easily influenced by external electric fields or strain. (C) 2011 American Institute of Physics. [doi: 10.1063/1.3624621

Room temperature magnetoelectric properties of type-II InAsSbP quantum dots and nanorings

“…However, strain effects in the systems studied in Ref. 4 due to the lattice mismatch to the surrounding InAs matrix compensate for this minimum in the conduction band offset and prevent an electron localization in InAsSb QDs. The magnetic flux leads to a periodic change in the quantum mechanical properties of the charge carrier system in QR and encircling the type-II QD.…”

“…The modified LPE has been employed to grow quantum well heterostructure lasers, 3 QD and QD/nanopits cooperative structures. [4][5][6][7] In this Letter, we present an example of quasi-ternary InAsSbP QDs and quantum rings (QRs) growth on InAs (100) substrates by modified LPE. The InAsSbP type-II QDs and QRs room temperature optoelectronic and magnetoelectric properties, as well as capacitance-voltage characteristics are investigated.…”

“…This geometry makes them particularly interesting for studies in magnetic fields, because for both cases this geometry defines a ring-like trajectory for electrons (or holes), ensuring that for instance in our type-II InAsSbP QDs the electron wave function is delocalized, as we have confirmed in previous calculations based on an eight-band kÁp-simulation. 4 Here, the free particle is the electron rather than the hole, which has a smaller effective mass. A strong band gap bowing in InAsSb induces a shallow conduction band minimum in InAsSb.…”

Growth and characterization of cooperative quantum dot chains in quaternary InAsSbP material system

“…28,29 Note, that all these nanostructure were grown on industrial InAs(100) substrates' epi-ready surface. In this study, the samples are grown by LPE at different contact duration of liquid phase with the substrate using a modified slide-boat crucible.…”

“…The physical reasons and nucleation features of CQDCs are the same as for InAsSbP QD-molecules. 28,29 CQDCs were nucleated at contact duration of liquid phase with the substrate of 30 minutes. Further increasing of the growth time up to two hours revealed the following interesting phenomena: (i) the coalescence and coarsening of the CQDCs (Fig.…”