Experimental and Theoretical Investigation of the Conduction Band Edge of GaNxP1-x

We show that a two-level band-anticrossing (BAC) model fails to describe the evolution of N-related states in Ga Nx P1-x. Band structure calculations prove that a two-level model describes these states in ordered GaNP supercells. Photocurrent measurements support a BAC-related blueshift of the GaP-like direct band gap in disordered GaNP, but calculations and electromodulated absorption and pressure studies show that the wide energy distribution of the lower-lying N-related states leads to the anticrossing interaction involving many N levels in disordered GaNP.