Theory of heat dissipation in molecular electronics

Pecchia, Alessandro; Romano, Giuseppe; Carlo, Aldo Di

doi:10.1103/physrevb.75.035401

Cited by 92 publications

(101 citation statements)

References 25 publications

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“…The reason is that the energy exchange between the electron and the phonon system is only a small fraction of the total electrical energy current. Equation (B5) is the difference between two large numbers, so our numerical integration has to be accurate enough to get a reasonable result 30 . On the contrary, Eq.…”

Section: Heat Generation In Current Carrying 1d Atomic Junctionsmentioning

confidence: 99%

“…II, we study the heat dissipation in current-carrying 1D atomic junctions 18,25,26,27,28,29,30,31 . In the presence of potential difference between the two leads, there will be electrical current flowing between them.…”

Section: Heat Generation In Current Carrying 1d Atomic Junctionsmentioning

confidence: 99%

“…Some simply assume that the phonons are in their thermal equilibrium states 31 . Some take into account the phonon transport by using the rate equations 30 or other semi-classical models 26,27,32 . Few of them take into account the quantum effect in heat transport 18,34 .…”

Section: Heat Generation In Current Carrying 1d Atomic Junctionsmentioning

confidence: 99%

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Coupled electron and phonon transport in one-dimensional atomic junctions

2007

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Employing the nonequilibrium Green's function method, we develop a fully quantum mechanical model to study the coupled electron-phonon transport in one-dimensional atomic junctions in the presence of a weak electron-phonon interaction. This model enables us to study the electronic and phononic transport on an equal footing. We derive the electrical and energy currents of the coupled electron-phonon system and the energy exchange between them. As an application, we study the heat dissipation in current carrying atomic junctions within the self-consistent Born approximation, which guarantees energy current conservation. We find that the inclusion of phonon transport is important in determining the heat dissipation and temperature change of the atomic junctions.

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Section: Heat Generation In Current Carrying 1d Atomic Junctionsmentioning

confidence: 99%

Section: Heat Generation In Current Carrying 1d Atomic Junctionsmentioning

confidence: 99%

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Coupled electron and phonon transport in one-dimensional atomic junctions

2007

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“…The temperature at the junction is a consequence of an equilibrium between heating due to electron flow and heat dissipation out of the junction. The former is dominated by the coupling of electronic molecular states with molecular vibrons [2,3,4]. The latter depends on the strength of the vibrational coupling between the "hot" molecular vibrons and the bath degrees of freedom of the "cold" electrodes.…”

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confidence: 99%

Resonant Electron Heating and Molecular Phonon Cooling in SingleC60Junctions

et al. 2008

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We study heating and heat dissipation of a single C60 molecule in the junction of a scanning tunneling microscope (STM) by measuring the electron current required to thermally decompose the fullerene cage. The power for decomposition varies with electron energy and reflects the molecular resonance structure. When the STM tip contacts the fullerene the molecule can sustain much larger currents. Transport simulations explain these effects by molecular heating due to resonant electronphonon coupling and molecular cooling by vibrational decay into the tip upon contact formation.The paradigm of molecular electronics is the use of a single molecule as an electronic device [1]. This concept is sustained on the basis that a single molecule (or a molecular thin film) should withstand the flow of electron current densities as large as 10 10 A/m 2 without degrading. A fraction of these electrons heat the molecular junction through inelastic scattering with the molecule [2]. The temperature at the junction is a consequence of an equilibrium between heating due to electron flow and heat dissipation out of the junction. The former is dominated by the coupling of electronic molecular states with molecular vibrons [2,3,4]. The latter depends on the strength of the vibrational coupling between the "hot" molecular vibrons and the bath degrees of freedom of the "cold" electrodes.Theoretical studies predicted that current-induced heating in molecular junctions can be large enough to affect the reliability of molecular devices [2]. However, experimental access to this information is very limited. Recent studies of the thermally activated force during molecular detachment from a lead [5,6] and of structural fluctuation during attachment to it [7] reveal that the temperature of a molecular junction can reach several hundred degrees under normal working conditions, thus revealing that present devices work on the limit of practical operability [8]. Heat dissipation away from the junction becomes an important issue.In this work, we characterize the mechanisms of heating and heat dissipation induced by the flow of current across a single molecule. Our approach is based on detecting the limiting electron current inducing molecular decomposition at varying applied source-drain bias (i.e. the maximum power one molecule can sustain). We use a low temperature scanning tunneling microscope (STM) to control the flow of electrons through a single C 60 molecule at an increasing rate until the molecule decomposes. By comparing the power applied for decomposition (P dec ) in tunneling regime and in contact with the STM tip we find that it depends significantly on two factors: i) P dec decreases when molecular resonances participate in the transport, evidencing that they enhance the heating; ii) P dec increases as the molecule is contacted to the source and drain electrodes, revealing the heat dissipation by phonon coupling to the leads. A good contact between the single-molecule (SM) device and the leads is hence an important requirement for its ope...

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“…On the other hand, the presence of interface critically defines underlying physical processes at atomic-scale, such as heat or electronic transport across the tip-sample contact in the scanning thermal microscope (SThM) 9,10 , scanning tunnelling microscope (STM) 11 , as well as thermoelectric energy conversion in molecular junctions 12 . Although limited by technical challenges, there are increasing activities focusing on the structural, electronic and thermal behaviours of atomic-scale junctions through experimental and theoretical approaches [12][13][14][15][16][17][18][19][20] , as well as mechanistic studies of SThM and STM 10,[21][22][23] . For example, Huang et al 24 probed the effective temperature of single-molecule junctions with currentinduced local heating as a function of molecular length and applied bias voltage.…”

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confidence: 99%

The critical power to maintain thermally stable molecular junctions

Wang

2014

Nat Commun

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With the rise of atomic-scale devices such as molecular electronics and scanning probe microscopies, energy transport processes through molecular junctions have attracted notable research interest recently. In this work, heat dissipation and transport across diamond/ benzene/diamond molecular junctions are explored by performing atomistic simulations. We identify the critical power P cr to maintain thermal stability of the junction through efficient dissipation of local heat. We also find that the molecule-probe contact features a powerdependent interfacial thermal resistance R K in the order of 10 9 kW À 1 . Moreover, both P cr and R K display explicit dependence on atomic structures of the junction, force and temperature. For instance, P cr can be elevated in multiple-molecule junctions, and streching the junction enhances R K by a factor of 2. The applications of these findings in molecular electronics and scanning probing measurements are discussed, providing practical guidelines in their rational design.

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Theory of heat dissipation in molecular electronics

Cited by 92 publications

References 25 publications

Coupled electron and phonon transport in one-dimensional atomic junctions

Coupled electron and phonon transport in one-dimensional atomic junctions

Resonant Electron Heating and Molecular Phonon Cooling in SingleC60Junctions

The critical power to maintain thermally stable molecular junctions

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