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Volumn 125, Issue 19, 2003, Pages 5948-5953

Long-range electron transfer through monolayers and bilayers of alkanethiols in electrochemically controlled Hg-Hg tunneling junctions

Author keywords

[No Author keywords available]

Indexed keywords

ELECTRON TRANSFER;

EID: 0038295856     PISSN: 00027863     EISSN: None     Source Type: Journal    
DOI: 10.1021/ja0211353     Document Type: Article
Times cited : (86)

References (78)
  • 49
    • 0038756571 scopus 로고    scopus 로고
    • note
    • The formation of a junction is accompanied by a small but sudden change in the shape of the Hg drop. This process may result in the formation of defects (cracks) within the monolayer outside the junction area. It was postulated that the alkanethiols present in the solution heal the defects created within the monolayer on Hg, thus making the junction more stable (see ref 6e).
  • 55
    • 0038418473 scopus 로고    scopus 로고
    • note
    • The differential capacitance measured at -0.75 V is independent of the presence of alkanethiol in a solution, thus indicafing that no physical adsorption occurs at this potential.
  • 56
    • 0038756568 scopus 로고    scopus 로고
    • note
    • The diameter of a Hg drop varied between 0.84 and 1 mm. The final diameter of a spontaneously formed tunneling junction was always ca. 26% of a drop diameter for both monolayer and bilayer junctions. The current density was independent of the junction radius.
  • 57
    • 0038756529 scopus 로고    scopus 로고
    • note
    • The bias voltage can be varied by changing the potential of one drop while keeping the potential of the second drop constant. The symmetric currentvoltage dependences, for both monolayer and bilayer junctions, are analogous to that reported earlier for two-electrode Hg-Hg junctions (see refs 6a-c). Within the voltage bias range of ±0.4 V we did not observe any rectification behavior.
  • 58
    • 0037742366 scopus 로고    scopus 로고
    • note
    • The stability of a junction depends on the chain length of the alkanethiol and not on the total number of carbon atoms across the junction. For example the octadecanethiol monolayer junction is more stable (the steadystate current is observed for a longer time) than the decanethiol monolayer junction. On the other hand, an octadecanethiol monolayer junction is more stable than a nonanethiol bilayer junction.
  • 59
    • 0038756530 scopus 로고    scopus 로고
    • note
    • For longer times, beyond the steady-state conditions, the current decreases or increases in an irreproducible manner. Clearly, the electrostatic squeezing changes tunneling efficiency (gauche defects formation), and it also changes the junction thickness (see ref 6b). Only steady-state current values are used in our data analysis.
  • 61
    • 0038756531 scopus 로고    scopus 로고
    • note
    • 4; lower concentrations of a salt caused a large IR drop, and the measurements were not reproducible.
  • 62
    • 0038756533 scopus 로고    scopus 로고
    • note
    • 2 must be kept at potentials more negative then -0.7 V to ensure that no self-assembly process occurs.
  • 70
    • 0038079882 scopus 로고    scopus 로고
    • note
    • We note that the attempts to form Hg-Hg junctions in the presence of 1-hexanol but in the absence of n-alkanethiol resulted in a coalescence of a junction regardless of the applied potentials.
  • 71
    • 0038756528 scopus 로고    scopus 로고
    • note
    • 2-group results in the constant change in the Hg-Hg distance. The argument can be made that shorter thiols form more "liquidlike" and less ordered monolayers. This scenario would result in a more shallow In i vs n dependence for shorter thiols.


* 이 정보는 Elsevier사의 SCOPUS DB에서 KISTI가 분석하여 추출한 것입니다.