Rectification of Current Responds to Incorporation of Fullerenes into Mixed-Monolayers of Alkanethiolates in Tunneling Junctions

Li Qiu, Yanxi Zhang, Theodorus Krijger, Xinkai Qiu, Patrick van 't Hof, Jan Hummelen, Ryan Chiechi

OnderzoeksoutputAcademicpeer review

26 Citaten (Scopus)
221 Downloads (Pure)


This paper describes the rectification of current through molecular junctions comprising self-assembled monolayers of decanethiolate through the incorporation of C60 fullerene moieties bearing undecanethiol groups in junctions using eutectic Ga–In (EGaIn) and Au conducting probe AFM (CP-AFM) top-contacts. The degree of rectification increases with increasing exposure of the decanethiolate monolayers to the fullerene moieties, going through a maximum after 24 h. We ascribe this observation to the resulting mixed-monolayer achieving an optimal packing density of fullerene cages sitting above the alkane monolayer. Thus, the degree of rectification is controlled by the amount of fullerene present in the mixed-monolayer. The voltage dependence of R varies with the composition of the top-contact and the force applied to the junction and the energy of the lowest unoccupied π-state determined from photoelectron spectroscopy is consistent with the direction of rectification. The maximum value of rectification R = |J(+)/J(−)| = 940 at ±1 V or 617 at ±0.95 V is in agreement with previous studies on pure monolayers relating the degree of rectification to the volume of the head-group on which the frontier orbitals are localized.
Originele taal-2English
Aantal pagina's8
TijdschriftChemical Science
StatusPublished - 20-dec-2016

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