Polarized photoreflectance spectroscopy of strained A-plane GaN films on R-plane sapphire

Polarized photoreflectance (PR) spectroscopy is used to investigate a [1120]- oriented A-plane GaN film on R-plane sapphire, where the c axis of GaN lies in the film plane. The results indicate that the observed transition energies and polarization properties of the three transitions can be used to describe the presence of an overall compressive, anisotropic in-plane strain in the film.