Odd–Even Effects in Charge Transport across n-Alkanethiolate-Based SAMs

• DOI: 10.1021/ja509436k
• Publication Date: 2014-11-07T18:18:43Z
• Authors: Mostafa Baghbanzadeh; Felice C. Simeone; Carleen M. Bowers; Kung-Ching Liao; Martin Thuo; Mahdi Baghbanzadeh; Michael S. Miller; Tricia Breen Carm...; George M. Whitesides
• Keywords: Self-assembled monolayer; Charge density

This paper compares rates of charge transport across self-assembled monolayers (SAMs) n-alkanethiolates having odd and even numbers carbon atoms (nodd neven) using junctions with the structure M(TS)/SAM//Ga2O3/EGaIn (M = Au or Ag). Measurements current density, J(V), SAMs on Au(TS) Ag(TS) demonstrated a statistically significant odd-even effect Au(TS), but not Ag(TS), that could be detected this technique. Statistical analysis showed values tunneling density nodd neven belonging to two separate sets, while there is difference between injection J0, for these series (log|J0Au,even| 4.0 ± 0.3 log|J0Au,odd| 4.5 0.3), decay constant, β, alkyl chains are indistinguishable (βAu,even 0.73 0.02 Å(-1), βAu,odd= 0.74 Å(-1)). A comparison electrical characteristics n-alkanethiolate gold silver electrodes yields β J0 indicates change substantially alters tilt angle chain (and, therefore, thickness SAM) has no influence n-alkanethiolates.