S. Ichikawa et al., Electronic states for InAs(111)A-(2 x 2)S surface studied by angle-resolved photoemission spectroscopy, SURF SCI, 454, 2000, pp. 509-513
Valence electronic states for an Inns(111)A-(2 x 2)S surface are investigat
ed by using synchrotron radiation angle-resolved photoemission spectroscopy
(SRARPES). Three bands at 1.0-1.2, 3.3, and 4.6-4.7 eV below the Fermi lev
el are found outside the projection of bulk bands along the (M) over bar-<(
Gamma)over bar>-(M) over bar and <(Gamma)over bar>-(K) over bar-(M) over ba
r azimuths. A band at 2.8 eV below the Fermi level is found in the normal e
mission spectra for the (2 x 2)S surface. This band is located within the p
rojection of bulk bands and independent of the momentum component normal to
the surface, k(perpendicular to). The four bands are ascribed to surface s
tates or surface resonances for the (2 x 2)S surface. The origin of the sur
face bands is discussed. (C) 2000 Elsevier Science B.V. All rights reserved
.