Surface-Site-Selective Study of Valence Electronic Structures of Clean Si(100)-2×1 Using Si-L₂₃VVAuger Electron–Si-2pPhotoelectron Coincidence Spectroscopy

Surface-site-selective study of valence electronic states of a clean Si(111)-7×7 surface using SiL23VVAuger electron and Si 2Kakiuchi1, Tahara2, Hashimoto3 et al. 2011Phys. Rev. BSelf Cite

“…I, the AeKE of the highest peak (AeKE HP ) in Si L 23 VV-Si 2p APECS provides information on the BE of the valence band at the highest DOS (BE VH ) associated with the surface site taken as the trigger. 18 The AeKE in a Si L 23 VV peak is generally given by the following equation: 18…”

“…where the superscripts S1 and S2 denote the two specific surface sites. 18 BE S1 2p and BE S2 2p can be estimated from Si 2p PES (see Fig. 1), while AeKE S1 HP and AeKE S2 HP are obtained from the surface-site-selective Si L 23 VV-Si 2p APECS (see 24 First-principles calculations 26 and a CITS study 3 ascribed them to the adatom dangling bonds, the rest-atom dangling bonds, and the adatom back bonds, respectively.…”

“…16,17 Very recently, we studied a clean Si(100)-2×1 surface in a surface-site-selective way using high-resolution Si L 23 VV Auger electron Si 2p photoelectron coincidence spectroscopy (Si L 23 VV-Si 2p APECS), and obtained information on the energy level where the valenceband density of states (DOS) is highest, and the valence-band maximum (VBM) in the vicinity of the Si up-atoms and the Si second layer. 18 In Si L 23 VV-Si 2p APECS, Si 2p photoelectrons with a fixed kinetic energy corresponding to specific sites are detected by an electron energy analyzer, while Auger electrons in the Si L 23 VV Auger electron region are measured by another analyzer. The intensity of an Si L 23 VV Auger peak (I L 23 V V ) is given by the equation…”

“…As the first step of discussing the local valence electronic structures, we assume that the highest peak of the Si L 23 VV-Si 2p APECS reflects the binding energy of the Si valence band at the highest DOS in the vicinity of the associated Si 2p sites, because e 2 /r V 1 V 2 is expected to be largest when the DOS becomes highest. 18 We can also discuss the binding energy of the VBM in the vicinity of a specific Si surface site based on APECS. The cutoff energy at the high Auger electron kinetic energy side of Si L 23 VV-Si 2p APECS corresponds to the VBM at the specific site.…”

“…The cutoff energy at the high Auger electron kinetic energy side of Si L 23 VV-Si 2p APECS corresponds to the VBM at the specific site. 18 Si L 23 VV-Si 2p APECS can probe any valence states, but is most suitable for investigations of local surface states because of the short ED APECS . Because Si 2p photoelectron peaks of silicon surface sites can be resolved in high-resolution SR-CL-PES, 19,20 Si L 23 VV-Si 2p APECS provides information on local valence electronic states in the vicinity of individual surface sites.…”