Exploring the band structure of Wurtzite InAs nanowires using photocurrent spectroscopy

We use polarized photocurrent spectroscopy in a nanowire device to investigate the band structure of hexagonal Wurtzite InAs. Signatures of optical transitions between four valence bands and two conduction bands are observed which are consistent with the symmetries expected from group theory. The ground state transition energy identified from photocurrent spectra is seen to be consistent with photoluminescence emitted from a cluster of nanowires from the same growth substrate. From the energies of the observed bands we determine the spin orbit and crystal field energies in Wurtzite InAs. This information is vital to the development of crystal phase engineering of this important III-V semiconductor.We acknowledge the financial support of the NSF through Grants DMR 1507844, DMR 1531373, and ECCS 1509706 and also the financial support of the Australian Research Council and the European Research Council (Grant No. 716471, ACrossWire). The Australian National Fabrication Facility (ACT Node) is acknowledged for access to the growth facility used in this work. The Australian Microscopy and Microanalysis Research Facility is acknowledged for access to the electron microscopes used in this work