Abstract
Junctions with the structure AgTS/S(CH2) nT//Ga2O3/EGaIn (where S(CH2) nT is a self-assembled monolayer, SAM, of n-alkanethiolate bearing a terminal functional group T) make it possible to examine the response of rates of charge transport by tunneling to changes in the strength of the interaction between T and Ga2O3. Introducing a series of Lewis acidic/basic functional groups (T = -OH, -SH, -CO2H, -CONH 2, and -PO3H) at the terminus of the SAM gave values for the tunneling current density, J(V) in A/cm2, that were indistinguishable (i.e., differed by less than a factor of 3) from the values observed with n-alkanethiolates of equivalent length. The insensitivity of the rate of tunneling to changes in the terminal functional group implies that replacing weak van der Waals contact interactions with stronger hydrogen- or ionic bonds at the T//Ga2O3 interface does not change the shape (i.e., the height or width) of the tunneling barrier enough to affect rates of charge transport. A comparison of the injection current, J0, for T = -CO2H, and T = -CH2CH3-two groups having similar extended lengths (in Å, or in numbers of non-hydrogen atoms)-suggests that both groups make indistinguishable contributions to the height of the tunneling barrier.
Original language | English |
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Pages (from-to) | 3521-3526 |
Number of pages | 6 |
Journal | Nano Letters |
Volume | 14 |
Issue number | 6 |
DOIs | |
Publication status | Published - 2014 Jun 11 |
Externally published | Yes |
Keywords
- EGaIn
- Tunneling
- charge transport
- interfaces
- molecular electronics
- self-assembled monolayers
ASJC Scopus subject areas
- Bioengineering
- Chemistry(all)
- Materials Science(all)
- Condensed Matter Physics
- Mechanical Engineering