INP(100)-(2X4) SURFACE ELECTRONIC-STRUCTURE STUDIED BY ANGLE-RESOLVEDPHOTOELECTRON-SPECTROSCOPY

The InP(100)-(2 x 4) surface electronic structure was studied using an gle-resolved photoelectron spectroscopy together with synchrotron radi ation. We identify three surface states occurring in the gaps of the p rojected bulk bands. The highest level state, located at binding energ y E-B = 1.0 eV, is consistent with previous findings, The second and t hird states, located at E-B = 1.8 eV and E-B = 4.3 eV, have not been r eported previously. All three of these surface states show no discerni ble dispersion compared with the surface states on InAs(100)-(2 x 4) a nd GaAs(100)-(2 x 4). This result suggests that the elements of the In P(100)-(2 x 4) surface unit cells are more isolated from each other th an they are for the InAs(100)-(2 x 4) or the GaAs(100)-(2 x 4) surface s. (C) 1998 Elsevier Science B.V.