Correspondence of experimental surface electronic structure of the Si(1 1 3)3×2 with structure models

The surface electronic structures of the Si(1 1 3)3×2 surface are studied in detail with angle-resolved photoelectron spectroscopy. Two surface states are observed in the [1 1 0] direction. A single dangling bond state having a broad line shape and large intensity at about 0.95 eV in normal emission spectrum is separated to two states, S1 and S2, at higher emission angles, different from the previous study. The dispersions of two states in the [1 1 0] direction are less than about 0.2 and 0.35 eV, respectively. Valence band spectra and LEED observations by Na adsorption on the 3×2 surface at room temperature show that the S1 state is preferentially quenched with the phase transition from the 3×2 to 3×1-Na surface. On the other hand, the S2 state starts to change after the complete quenching of S1 state and the phase transition. From these results, the origins of two dangling bond states are discussed based on Ranke’s and the puckering structural model for the 3×2 surface.