SURFACE ELECTRONIC-STRUCTURE OF MONOLAYER BI ON INP(110)

The two-dimensional electronic bandstructure of monolayer Bi on InP(11 0) has been mapped by angle resolved ultra violet photoelectron spectr oscopy using synchrotron radiation. The dispersion of the features in the valence band spectra was followed along the four symmetry directio ns of the surface Brillouin zone. It is possible to distinguish five s tates as surface related. The topmost band is found to be inside the f undamental band gap, at about 0.45 eV above the valence band maximum. Limited application of polarisation effects was made to probe the natu re of the states. In the absence of a suitable calculation, the result s are compared to measurements and calculations of other V/III-V(110) systems.