S. Perera

Nearly intrinsic exciton lifetimes in single twin-free GaAs/AlGaAs core-shell nanowire heterostructures

S.P., M.A.F., H.E.J., L.M.S., and J.M.Y.-R. acknowledge the financial support of the University of Cincinnati and the National Science Foundation through Grant Nos. EEC/NUE- 0532495, ECCS-0701703, and DMR/MWN-0806700. H.J.J., Q.G., H.H.T., C.J., X.Z., and J.Z. acknowledge support from the Australian Research Council and the Australian National Fabrication Facility.

Probing valence band structure in wurtzite InP nanowires using excitation spectroscopy

We use time-resolved photoluminescence spectroscopy and photoluminescence excitation spectroscopy to measure the valence band parameters of hexagonal wurtzite InP nanowires. The A exciton emission and excitation energy is observed at 1.504 eV as expected. Excitation spectra show that the B and C hole bands are 30 and 161 meV above the A hole band. From these measurements, we obtain the crystal field and spin-orbit energies of 52 meV and 139 meV, respectively.

Probing the valence band structure of wurtzite InP nanowires by photoluminescence excitation spectroscopy

We use time-resolved photoluminescence and photoluminescence excitation spectroscopy to obtain the valence band parameters of wurtzite InP nanowires. We observe the A, B, and C hole bands for these nanowires and obtain both the crystal field and the spin-orbit energies for wurtzite InP nanowires.

Optical properties of single InP and GaAs nanowire heterostructures

Semiconductor nanowire (NW) heterostructures are increasingly important building blocks for electronic and optoelectronic devices. III-V nanowires with attention to well-controlled growth parameters, high structural quality and high optical quality NWs with unusually long recombination lifetimes can be achieved. We probe these NWs experimentally with both CW and time-resolved photoluminescence spectroscopy. The large surface-to-volume ratio is an intrinsic characteristic of nanowires which highlights the critical importance of surface and interface quality.