Valence band splitting in wurtzite InGaAs nanoneedles studied by photoluminescence excitation spectroscopy.

We use low-temperature microphotoluminescence and photoluminescence excitation spectroscopy to measure the valence band parameters of single wurtzite InGaAs nanoneedles. The effective indium composition is measured by means of polarization-dependent Raman spectroscopy. We find that the heavy-hole and light-hole splitting is ∼95 meV at 10 K and the Stokes shift is in the range of 35-55 meV. These findings provide important insight in the band structure of wurtzite InGaAs that could be used for future bandgap engineering.