POLARIZATION-DEPENDENT ANGLE-RESOLVED PHOTOEMISSION-STUDY OF A SURFACE-STATE ON GASB(110)

Using polarization-dependent, angle-resolved photoemission, a prominen t nondispersive structure in the normal emission spectra from GaSb(110 ) has been identified as being due to transitions from the Sb-derived dangling-bond surface state. The atomic-orbital character of the surfa ce state was confirmed to be mainly p(z)-like, and the dispersion of t he surface state along the GAMMABAR XBAR direction in the surface Bril louin zone was observed. Using symmetry selection rules, an accurate d etermination of GAMMA8v, the valence-band maximum (VBM), was made. The surface state was found to be 150+/-100 meV above the VBM, showing th at the surface state is indeed an intrinsic intergap surface state.