Valence Band Splitting in Wurtzite InP Nanowires Observed by Photoluminescence and Photoluminescence Excitation Spectroscopy

We have investigated individual bulk-like wires of wurtzite InP using photoluminescence, photoluminescence excitation spectroscopy and transmission electron microscopy. Using two different methods we find that the top of the valence band is split, as expected theoretically. This splitting of the valence band is peculiar to wurtzite InP and does not occur in zinc blende InP. We find the energy difference between the two bands to be 40 meV.