Evidence of type-II band alignment at the ordered GaInNP to GaAs heterointerface



Polarized piezoreflectance (PzR) and photoreflectance (PR) are employed to study band alignment in Ga0.46In0.54Ny P1–y/GaAs heterostructures grown by gas-source molecular-beam epitaxy. The features near the band edge of Ga0.46In0.54Ny P1–y show strong polarization dependence, indicating the existence of some degree of ordering of these samples. The PR spectra exhibit Franz–Keldysh Oscillations (FKOs) above the band edge of GaAs. The electric fields in the GaAs region are evaluated by analyzing the FKOs and found to decrease with increasing nitrogen content. The type-II band alignment at the Ga0.46In0.54Ny P1–y/GaAs interface is concluded for the alloys with nitrogen content y larger than 0.5% based on the appearance of additional features below band edge of GaAs. These features are attributed to the spatially indirect type-II transitions in the vicinity of interface region between Ga0.46In0.54Ny P1–y and GaAs. (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)