Observation of an inverted band structure near the surface of InN

The dispersion of the valence band within the electron accumulation layer of n-type has been directly measured using angle-resolved photoemission spectroscopy. Intermixing between the heavy-hole and light-hole valence bands in the intrinsic quantum well potential associated with the near-surface electron accumulation layer results in an inverted band structure, with the valence band maximum lying away from the Brillouin zone center. Such an inverted band structure has not previously been observed in an intrinsic accumulation layer.