Electronic band structure of wurtzite GaP nanowires via temperature dependent resonance Raman spectroscopy

Resonance Raman measurements are carried out on defect-free wurtzite GaP nanowires over the excitation energy range between 2.19 and 2.71 eV. Resonances of the E-1(LO) and A(1)(LO) modes demonstrate the existence of energy states with Gamma(9hh) and Gamma(7V) (Gamma(7C)) symmetries of the valence (conduction) band and enable us to measure wurtzite phase GaP band energies. In addition, we have performed temperature dependent resonant Raman measurements, which allowed us to extrapolate the zero temperature values of Gamma point energies. Our results provide the necessary feedback required for refining the available theoretical calculations to derive the correct wurtzite III-V semiconductor band structure.