Surface and interface phonon polaritons of wurtzite GaN thin film grown on 6H-SiC substrate

Surface and interface phonon polaritons of wurtzite GaN thin film grown on 6H-SiC substrate are investigated experimentally and theoretically. Two strong absorption peaks that correspond to the surface and interface phonon polaritons are clearly observed at 710 and 916 cm−1, respectively. This observation is in good agreement with the results simulated using an anisotropy model. Finally, the obtained surface phonon polariton (SPP) mode is compared with the reported result. It is revealed that the SPP mode in the wurtzite GaN thin film is shifted toward higher frequency as compared to that in the wurtzite bulk GaN.