First-principles quantum transport modeling of thermoelectricity in single-molecule nanojunctions with graphene nanoribbon electrodes

Abstract

We overview nonequilibrium Green function combined with density functional theory (NEGF-DFT) modeling of independent electron and phonon transport in nanojunctions with applications focused on a new class of thermoelectric devices where a single molecule is attached to two metallic zigzag graphene nanoribbons (ZGNRs) via highly transparent contacts. Such contacts make possible injection of evanescent wavefunctions from ZGNRs, so that their overlap within the molecular region generates a peak in the electronic transmission. Additionally, the spatial symmetry properties of the transverse propagating states in the ZGNR electrodes suppress hole-like contributions to the thermopower. Thus optimized thermopower, together with diminished phonon conductance through a ZGNR/molecule/ZGNR inhomogeneous structure, yields the thermoelectric figure of merit ZT~0.5 at room temperature and 0.5<ZT<2.5 below liquid nitrogen temperature. The reliance on evanescent mode transport and symmetry of propagating states in the electrodes makes the electronic-transport-determined power factor in this class of devices largely insensitive to the type of sufficiently short conjugated organic molecule, which we demonstrate by showing that both 18-annulene and C10 molecule sandwiched by the two ZGNR electrodes yield similar thermopower. Thus, one can search for molecules that will further reduce the phonon thermal conductance (in the denominator of ZT) while keeping the electronic power factor (in the nominator of ZT) optimized. We also show how often employed Brenner empirical interatomic potential for hydrocarbon systems fails to describe phonon transport in our single-molecule nanojunctions when contrasted with first-principles results obtained via NEGF-DFT methodology.

20 pages, 6 figures; mini-review article prepared for the special issue of the Journal of Computational Electronics on "Simulation of Thermal, Thermoelectric, and Electrothermal Phenomena in Nanostructures", edited by I. Knezevic and Z. Aksamija

References in corpus (28)

• Molecular Transport Junctions: Vibrational Effects
• Thermoelectric and Magnetothermoelectric Transport Measurements of Graphene
• Magnetic Correlations at Graphene Edges
• Quantum thermal transport in nanostructures
• Edge-functionalized and substitutional doped graphene nanoribbons: electronic and spin properties
• Inelastic transport theory from first-principles: methodology and applications for nanoscale devices
• Charge Transport in Disordered Graphene-Based Low Dimensional Materials
• Room-temperature gating of molecular junctions using few-layer graphene nanogap electrodes
• Giant thermopower and figure of merit in single-molecule devices
• Optimal thermoelectric figure of merit of a molecular junction
• Violation of the Wiedemann-Franz Law in a Single-Electron Transistor
• Tunneling through molecules and quantum dots: master-equation approaches
• Electron- and phonon transport in silicon nanowires: an atomistic approach to thermoelectric properties
• Giant Thermoelectric Effect from Transmission Supernodes
• First-principles study of heat transport properties of graphene nanoribbons
• Vibrational modes and low-temperature thermal properties of graphene and carbon nanotubes: A minimal force-constant model
• Length-dependent conductance and thermopower in single-molecule junctions of dithiolated oligophenylene derivatives
• Coupled electron and phonon transport in one-dimensional atomic junctions
• The transfer of energy between electrons and ions in solids
• Multiterminal single-molecule--graphene-nanoribbon thermoelectric devices with gate-voltage tunable figure of merit ZT
• Inelastic effects in molecular junction transport: Scattering and self-consistent calculations for the Seebeck coefficient
• Quantum-interference-controlled three-terminal molecular transistors based on a single ring-shaped-molecule connected to graphene nanoribbon electrodes
• Seebeck coefficient of thermoelectric moleculat junction: First-principles calculations
• Current noise in molecular junctions: effects of the electron-phonon interaction
• Joule heating and thermoelectric properties in short single-walled carbon nanotubes: electron-phonon interaction effect
• The Phonon Drag Effect in Single-Walled Carbon Nanotubes
• Seebeck Coefficients in Nanoscale Junctions: Effects of Electron-vibration Scattering and Local Heating
• Quantum Interference Controlled Molecular Electronics

Cited by in corpus (24)

• Nonequilibrium Green's function method for quantum thermal transport
• Giant thermoelectric effect in graphene-based topological insulators with nanopores
• Edge currents and nanopore arrays in zigzag and chiral graphene nanoribbons as a route toward high-$ZT$ thermoelectrics
• First-principles calculation of the thermoelectric figure of merit for [2,2]paracyclophane-based single-molecule junctions
• Efficiency fluctuations in quantum thermoelectric devices
• Scattering Theory of Nonlinear Thermoelectricity in Quantum Coherent Conductors
• Mechanical Tuning of Thermal Transport in a Molecular Junction
• Manipulating the voltage drop in graphene nanojunctions using a gate potential
• Thermoelectric efficiency of nanoscale devices in the linear regime
• Spin-Seebeck effect on the surface of topological insulator due to nonequilibrium spin-polarization parallel to the direction of thermally driven electronic transport
• Molecular Heat Engines: Quantum Coherence Effects
• Origin of thermoelectric response fluctuations in single-molecule junctions
• Interband tunneling effects on materials transport properties using the first principles Wigner distribution
• Bilayer graphene nanoribbons junction with aligned holes exhibiting high ZT values
• The effect of fluctuations - thermal and otherwise - on the temperature dependence of thermopower in aromatic chain single-molecule junctions
• Theoretical insight into the thermoelectric behavior of tri-nuclear metal-string complexes laced with gold nanoelectrodes: A first-principles study
• Odd-even phonon transport effects in strained carbon atomic chains bridging graphene nanoribbon electrodes
• Electron Transport in Molecular Junctions with Graphene as Protecting Layer
• Heat, particle and chiral currents in a boundary driven bosonic ladders in presence of gauge fields
• Atomistic modeling of dynamical quantum transport
• Interplay of electron and phonon channels in the refrigeration through molecular junctions
• Non-equilibrium boundary driven quantum systems: models, methods and properties
• Thermoelectric efficiency in multiterminal quantum thermal machines from steady-state density functional theory
• Thermopower in a boundary driven bosonic ladder in the presence of a gauge field