Photoluminescence of Mn-catalyzed GaAs nanowires grown by molecular beam epitaxy

We present photoluminescence spectra of GaAs nanowires and nanoleaves grown by molecular beam epitaxy using Mn as growth catalyst. At low temperature and low excitation intensity the spectra are characterized by several narrow peaks superimposed onto a broader band. The peak at the highest energy is located at 1.522 eV, i.e. 7 meV above the free exciton position in GaAs, irrespective of growth conditions and of the shape and size of the nanostructures. We suggest that this peak originates from electron-hole recombination in wurtzite-type GaAs.