| Abstract
| - The electronic properties of alkanethiolate [CH3(CH2)nS−, n = 9 and 11] and alkaneselenolate [CH3(CH2)nSe−, n = 9 and 11] self-assembled monolayers on Au{111} have been quantitatively compared. Simultaneouslyacquired apparent tunneling barrier height (ATBH) and scanning tunneling microscopy (STM) images revealthat alkanethiolate molecules have a lower barrier to tunneling, and therefore a higher conductance thanalkaneselenolates of the same alkyl chain length. Molecular and contact conductance differences were elucidatedby using observed STM topographic tunneling height differences between the analogous species. This apparenttopographic difference combined with comparative ATBH data indicate that the observed decrease inconductance for alkaneselenolates compared to alkanethiolates originates exclusively from the Au-chalcogenidephysical, chemical, and electronic contact.
|
