There has been intense interest in recent years to control the electronic structure in quasi one-dimensional nanowires through the fabrication of novel axial and radial heterostructures. Unlike materials in higher dimensions, nanowires have the unique ability to grow axial or radial heterostructures between almost any two materials regardless of lattice mismatch or strain. Understanding exactly how the electronic properties of the nanowire are changed through this control is extremely important and requires spectroscopies with high spatial, temporal and spectral resolution. I will discuss a number of examples in which the electronic structure in nanowire heterostructures can be modified either through strain, crystal structure, or quantum confinement, and what insights can be provided by a number of single nanowire optical spectroscopies.

This effort is the result of collaborations with the research groups of Chennupati Jagadish at Australian National University, Joanne Etheridge at Monash University, Howard Jackson at University of Cincinnati, Jan Yarrison-Rice at Miami University, and Bryan Wong at the University of California Riverside.

This work was supported by the NSF through DMR-1105362, 1105121 and ECCS-1100489, and also the Australian Research Council (ARC) and the Australian National Fabrication Facility.

"Illuminating the Second Conduction Band and Spin-Orbit Energy in Single Wurtzite InP Nanowires," S. Perera, et al, Nano Letters 13, 5367 (2013).

"Optical, Structural, and Numerical Investigations of GaAs/AlGaAs Coreï¿½Multishell Nanowire Quantum Well Tubes," M.A. Fickenscher et al., Nano Letters 13, 1016 (2013).

Transient Rayleigh Scattering: A new probe of picosecond carrier dynamics in a single semiconductor nanowire, M. Montazeri et al, Nano Letters 12, 5389-5395 (2012).

Direct Measure of Strain and Electronic Structure in GaAs/GaP Core-Shell Nanowires, Mohammad Montazeri, et al., Nano Letters, 10, 880-886 (2010).

Leigh Smith

University of Cincinnati

Appearances