Recent advances in semiconductor nanowire heterostructures

We review a selection of recent optical experiments which provide unique characterizations of the energy landscape in semiconductor nanowires, both simple nanowires and more complex semiconductor heterostructures. The optical experiments include the techniques of photoluminescence, time-resolved photoluminescence, photoluminescence excitation spectroscopy, photocurrent spectroscopy, and Raman scattering brought to bear on structures from simple core-shell structures, to axial heterostructures, to core-multiple-shell heterostructures. The physics that is illuminated ranges from localization of excitons in GaAs quantum well tubes, to strain in GaAs/GaP axial heterostructures, to carrier relaxation dynamics in GaAs/AlGaAs core-shell NWs probed by the new technique of transient Rayleigh scattering