A high-resolution photoemission study of ethanol adsorption on Si(111)-(7×7)

Adsorption of 2,3-butanediol on Si(1 0 0)

“…It is worthwhile to compare the current experimental spectrum with the calculated results especially due to the fact that there has been no MO calculation or spectroscopic measurement even for the free 2,3-butanediol molecule so far. The theoretical values for ethanol are nearly identical to the spectrum observed by Carbone et al [6] or Casaletto et al [7] as shown on the top of Fig. 1.…”

“…The adsorption of 2,3-butanediol causes a remarkable change where the whole range of the spectrum exhibits peaks due to molecular orbitalrelated transitions labeled A through G. Many peaks show a close similarity to previous results on ethanol adsorption [6,7], probably because the 2,3-butanediol has a molecular structure of two added units of ethanol. However, there remains a broad bulk peak at 2.5 eV, while all the Si features are reduced for ethanol.…”

“…O 2p), it is assumed that a significant change occurs on those MO's from the interaction between the molecule and substrate. As a second comparison, the feature at 12-13 eV is absent in the top spectrum for ethanol adsorption at RT, which is due to the O-H bond cleavage of the ethanol [5,6]. This has been the most obvious change in the valence band upon chemisorption of simple alcohols on the Si substrate.…”

“…Fig. 1 shows such spectra taken before and after exposure of 2,3-butanediol on a Si(1 0 0) surface, including a previous spectrum for ethanol adsorption on the top [6]. Clean Si(1 0 0) shows two clear features at 0.8 and 2.0 eV due to surface and bulk states, respectively, though the latter peak at 2.0 eV has bulk and surface resonance character [12].…”

“…Methanol or ethanol adsorption on a Si(1 0 0) or (1 1 1) surface has been studied by reflection IR spectroscopy and photoemission [5][6][7][8][9]. They react in a very similar fashion, i.e.…”