Simultaneous Determination of Conductance and Thermopower of Single Molecule Junctions

Citations Over TimeTop 1% of 2011 papers

Abstract

We report the first concurrent determination of conductance (G) and thermopower (S) of single-molecule junctions via direct measurement of electrical and thermoelectric currents using a scanning tunneling microscope-based break-junction technique. We explore several amine-Au and pyridine-Au linked molecules that are predicted to conduct through either the highest occupied molecular orbital (HOMO) or the lowest unoccupied molecular orbital (LUMO), respectively. We find that the Seebeck coefficient is negative for pyridine-Au linked LUMO-conducting junctions and positive for amine-Au linked HOMO-conducting junctions. Within the accessible temperature gradients (<30 K), we do not observe a strong dependence of the junction Seebeck coefficient on temperature. From histograms of thousands of junctions, we use the most probable Seebeck coefficient to determine a power factor, GS(2), for each junction studied, and find that GS(2) increases with G. Finally, we find that conductance and Seebeck coefficient values are in good quantitative agreement with our self-energy corrected density functional theory calculations.

Related Papers

• → Single‐Molecule Conductance of π‐Conjugated Rotaxane: New Method for Measuring Stipulated Electric Conductance of π‐Conjugated Molecular Wire Using STM Break Junction(2012)76 cited
• → Thermoelectric Properties of 2,7-Dipyridylfluorene Derivatives in Single-Molecule Junctions(2018)44 cited
• → An electrochemically assisted mechanically controllable break junction approach for single molecule junction conductance measurements(2011)29 cited
• → Charge Transport through a Single Molecule of trans-1-bis-Diazofluorene [60]fullerene(2017)5 cited
• → Molecular break-junctions: interaction with light and conductance switching(2005)