The evolution of the band structure of the ${\mathrm{GaN}}_x{\mathrm{P}}_{1-x}$ alloy, under dilute nitrogen concentrations $(x=0,$ 0.0028, 0.0086, 0.0210, and 0.0310), is investigated using ballistic electron emission spectroscopy (BEES). The observation of fine structure in the BEES spectra of GaNP samples is discussed in terms of a possible splitting in the degeneracy of the X valley due to the nitrogen induced intense perturbation in the GaP lattice. For an incorporation of 3% of N, the reduction in the band gap is approximately measured to be 300 meV. The data are qualitatively described by the recent perturbed host states model of Kent and Zunger.

• Received 24 July 2002

DOI:https://doi.org/10.1103/PhysRevB.66.235313