Field-Effect Control of Graphene-Fullerene Thermoelectric Nanodevices
arXiv:1710.08344 · doi:10.1021/acs.nanolett.7b03736
Abstract
Although it was demonstrated that discrete molecular levels determine the sign and magnitude of the thermoelectric effect in single-molecule junctions, full electrostatic control of these levels has not been achieved to date. Here, we show that graphene nanogaps combined with gold microheaters serve as a testbed for studying single-molecule thermoelectricity. Reduced screening of the gate electric field compared to conventional metal electrodes allows control of the position of the dominant transport orbital by hundreds of meV. We find that the power factor of graphene-fullerene junctions can be tuned over several orders of magnitude to a value close to the theoretical limit of an isolated Breit-Wigner resonance. Furthermore, our data suggest that the power factor of an isolated level is only given by the tunnel coupling to the leads and temperature. These results open up new avenues for exploring thermoelectricity and charge transport in individual molecules and highlight the importance of level alignment and coupling to the electrodes for optimum energy conversion in organic thermoelectric materials.
References in corpus (15)
- Spins in few-electron quantum dots
- Thermoelectric and Magnetothermoelectric Transport Measurements of Graphene
- Hot Carrier Transport and Photocurrent Response in Graphene
- Room-temperature gating of molecular junctions using few-layer graphene nanogap electrodes
- Giant thermopower and figure of merit in single-molecule devices
- Simultaneous Determination of Conductance and Thermopower of Single Molecule Junctions
- Modulation of Thermoelectric Power of Individual Carbon Nanotubes
- Molecular design and control of fullerene-based bi-thermoelectric materials
- Hierarchical Quantum Master Equation Approach to Electronic-Vibrational Coupling in Nonequilibrium Transport through Nanosystems
- Franck-Condon Blockade in a Single-Molecule Transistor
- Nonlinear thermovoltage and thermocurrent in quantum dots
- Nanoscale spatial resolution probes for Scanning Thermal Microscopy of solid state materials
- Quantum Interference in Graphene Nanoconstrictions
- On the Mott formula for thermopower of non-interactions electrons in quantum point contacts
- Three-terminal graphene single-electron transistor fabricated using feedback-controlled electroburning
Cited by in corpus (12)
- Thermoelectric Performance of 2D Tellurium with Accumulation Contacts
- Direct measurement of the Seebeck coefficient in a Kondo-correlated single-quantum-dot transistor
- Direct Mapping of Local Seebeck Coefficient in 2D Material Nanostructures via Scanning Thermal Gate Microscopy
- Marcus Theory of Thermoelectricity in Molecular Junctions
- Controlling the entropy of a single-molecule junction
- Magnetic Field Universality of the Kondo Effect Revealed by Thermocurrent Spectroscopy
- Efficient heating of single-molecule junctions for thermoelectric studies at cryogenic temperatures
- Electronic measurements of entropy in meso- and nanoscale systems
- The role of metallic leads and electronic degeneracies in thermoelectric power generation in quantum dots
- A Mechanically Tunable Quantum Dot in a Graphene Break Junction
- Thermoelectricity of near-resonant tunnel junctions and their near-Carnot efficiency
- Classifying destructive quantum interference in molecular junctions: Towards molecular quantum rulers