Probing the electronic structures of III–V-nitride semiconductors by x-ray photoelectron spectroscopy

The electronic structures of III–V-nitride semiconductors, including InGaAsN, GaAsN, and InAsN grown by molecular beam epitaxy, were investigated by high-resolution x-ray photoelectron spectroscopy using synchrotron radiation beam and low energy Ar+ sputtering. The N(1s) core-level photoelectron spectra show a single peak with a binding energy (Eb)∼398.0 eV of N–Ga bonding for GaAsN sample. For the InAsN samples, a single N(1s) peak at Eb∼397.0 eV of N–In bonding is observed. For the InGaAsN samples, the N(1s) spectra exhibit two peaks with a major component corresponding to N–In bonding, and a minor one to N–Ga bonding. The integrated N(1s) intensity of N–In bonding has a higher value than that of N–Ga bonding, in spite of the lower mole fraction of In for the InGaAsN sample. The data indicate that N has a bonding configuration with In-rich nearest neighbors in the InGaAsN samples.