Atomic resolution structure and spectroscopy of semiconducting nanowires
Supervisors: Ana M Sanchez and Richard Beanland
Group :
Microscopy
The field of semiconductor nanowires (NWs) has become one of the most active research areas in
the nanoscience community1 in the last five years. Integration of semiconducting NWs with the wellestablished capabilities and low production cost of silicon is crucial for the implementation of novel
quantum emitters, such as single photon sources on Si.
Development of this area requires control of the nanowire structure with atomic precision, and this
in turn is reliant on the ability to map structural and electronic properties with atomic resolution. With
the recent advances in hardware, such as aberration correction, electron microscopy is the technique of
choice to disentangle the structural properties of the material and correlate them with the functional
ones.
This project will involve the atomic scale characterisation of a range of semiconducting nanowires,
supplied by our collaborators who are internationally leading nanowire growth experts. The successful
applicant will be trained in the use of the doubly aberration corrected TEM/STEM at Warwick, the only
such facility in the UK, which has the capability for sub-Å resolution imaging and spectroscopy. The
aim will be to determine the atomic scale structure and composition of the nanowires, and to correlate
these to changes in optical properties and electronic structure. Calculation of the critical dimensions for
the plastic relaxation of axial heterostructures in nanowires is also anticipated. The candidate will be
joining a group with an internationally-competitive electron microscopy facility with excellent
specimen preparation and microscopy and many years of experience studying semiconductor materials.
Strong collaboration with external partners at universities (such as UCL, Sheffield and Lancaster
universities) and semiconductor industries (such as, Hitachi and Huawei) will be an essential part of the
project. The successful applicant should have a good degree in Physics, or related subjects, good
background knowledge of semiconductor Physics is preferred. Interested students should contact
a.m.sanchez@warwick.ac.uk (Tel. 02476151372)
Figure 1. (a) Side-view SEM image of the core–shell GaAs0.8P0.2 NWs. (b) Conventional Dark
field TEM image and the diffraction pattern of a GaAs0.8P0.2 core–shell NW. (c) Highmagnification annular dark field image of the NW shown in (b). Ref. [2]
1
2
P. Yang et al, Nano Lett 2010, 10, 1529
Y. Zhang et al. Nano Lett 2015, 15, 3128