SURFACE TERMINATION OF GAAS(001) BY SB DIMERS

Angle-integrated and angle-resolved (AR) photoelectron spectroscopy (P ES) experiments were performed on GaAs(001) 2 x 4 Sb surfaces. The res ults of angle-integrated PES show that only Sb atoms lie on the GaAs s urface and that they bond to Ga atoms. ARPES experiments revealed a su rface state whose dispersion is very similar to the As dimer dangling bond surface stare of As-terminated GaAs(001). These results suggested that Sb dimers terminate GaAs surfaces and bond to Ga atoms of the se cond top atomic layer.