Inverse photoemission study of InP, InAs, and InSb

Unoccupied bulk and surface electronic states of InP, InAs, and InSb are determined via inverse photoemission from their cleaved (110) surfaces. With use of a tunable photon detector, the band dispersion of the lowest p-like bands along the ΓΣKX line is mapped and the critical points ${\Gamma }_{15}$ and $X_1$ of the conduction band are determined (${\Gamma }_{15}$=5.3, 4.5, and 4.2 eV and $X_1$=2.8, 1.9, and 1.8 eV, for InP, InAs, InSb, respectively). Surface resonances are found in the region 1.9–2.7 eV above the valence-band maximum. Resonance effects near the In 4d core-level threshold and the onset of In 4d luminescence are studied.