TY - JOUR
T1 - Facile charge-displacement at silicon gives spaced-out reaction
AU - Ebrahimi, Maryam
AU - Huang, Kai
AU - Lu, Xuekun
AU - McNab, Iain R.
AU - Polanyi, John C.
AU - Waqar, Zafar
AU - Yang, Jody
AU - Lin, Haiping
AU - Hofer, Werner A.
N1 - Copyright:
Copyright 2012 Elsevier B.V., All rights reserved.
PY - 2011/10/19
Y1 - 2011/10/19
N2 - Adsorbates on metals, but not previously on semiconductors, have been observed to display long-range repulsive interactions. On metals, due to efficient dissipation, the repulsions are weak, typically on the order of 5 meV at 10 Å. On the 7×7 reconstruction of the Si(111) surface, charge transport through the surface has been demonstrated by others using charge injection by STM tips. Here we show that for both physisorbed brominated molecules, and for chemisorbed Br-atoms, induced charge-transfer in the Si(111)-7×7 surface can lead to a strong repulsive interaction between adsorbates, calculated as 200 meV at 13.4 Å. This large repulsive interaction must be channeled through the surface since it causes widely spaced "one-per-corner-hole" patterns of physisorption (three cases-directly observed here) and subsequent chemisorption (four cases observed). The patterns were observed by ultrahigh vacuum scanning tunneling microscopy for four different brominated hydrocarbon adsorbates; 1,2-dibromoethane, 1-bromopropane, 1-bromopentane, and bromobenzene, deposited individually on the surface. In every case, adsorbates were overwhelmingly more likely to be found singly than multiply adjacent to a corner-hole, constituting a distinctive pattern having a probability p = 7 × 10 -5 compared to a random distribution.
AB - Adsorbates on metals, but not previously on semiconductors, have been observed to display long-range repulsive interactions. On metals, due to efficient dissipation, the repulsions are weak, typically on the order of 5 meV at 10 Å. On the 7×7 reconstruction of the Si(111) surface, charge transport through the surface has been demonstrated by others using charge injection by STM tips. Here we show that for both physisorbed brominated molecules, and for chemisorbed Br-atoms, induced charge-transfer in the Si(111)-7×7 surface can lead to a strong repulsive interaction between adsorbates, calculated as 200 meV at 13.4 Å. This large repulsive interaction must be channeled through the surface since it causes widely spaced "one-per-corner-hole" patterns of physisorption (three cases-directly observed here) and subsequent chemisorption (four cases observed). The patterns were observed by ultrahigh vacuum scanning tunneling microscopy for four different brominated hydrocarbon adsorbates; 1,2-dibromoethane, 1-bromopropane, 1-bromopentane, and bromobenzene, deposited individually on the surface. In every case, adsorbates were overwhelmingly more likely to be found singly than multiply adjacent to a corner-hole, constituting a distinctive pattern having a probability p = 7 × 10 -5 compared to a random distribution.
UR - http://www.scopus.com/inward/record.url?scp=80054761996&partnerID=8YFLogxK
U2 - 10.1021/ja205716t
DO - 10.1021/ja205716t
M3 - 文章
C2 - 21879758
AN - SCOPUS:80054761996
VL - 133
SP - 16560
EP - 16565
JO - Journal of the American Chemical Society
JF - Journal of the American Chemical Society
SN - 0002-7863
IS - 41
ER -