Anomalous kink behavior in the current-voltage characteristics of suspended carbon nanotubes

Amer, Moh. R.; Bushmaker, Adam; Cronin, Stephen B.

doi:10.1007/s12274-012-0197-2

Cited by 16 publications

(22 citation statements)

References 23 publications

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“…Characterization : Devices are considered by measuring the I–V bias characteristics under high bias for each device. Devices that show a maximum current I max ≈ 10/ L, where L is the trench width in micrometer and I max is in microampere, correspond to individual carbon nanotubes and are selected for further study . Raman spectra of these individual quasi‐metallic nanotubes along with photocurrent spectra are measured as shown in the (Figures S1,S2, Supporting Information).…”

Section: Methodsmentioning

confidence: 99%

Competing Photocurrent Mechanisms in Quasi‐Metallic Carbon Nanotube pn Devices

Amer

Chang

Cronin

2015

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Photodetectors based on quasi-metallic carbon nanotubes exhibit unique optoelectronic properties. Due to their small bandgap, photocurrent generation is possible at room temperature. The origin of this photocurrent is investigated to determine the underlying mechanism, which can be photothermoelectric effect or photovoltaic effect, depending on the bandgap magnitude of the quasi-metallic nanotube.

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Section: Methodsmentioning

confidence: 99%

Competing Photocurrent Mechanisms in Quasi‐Metallic Carbon Nanotube pn Devices

Amer

Chang

Cronin

2015

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“…With these properties applied in integrated circuits and in the field effect transistors' gate electrodes metallic CNTs lead the minituarisation race at the nanoscale [4]. However experimental and theoretical studies show that electronic transport in metallic CNTs undergoes a dramatic decrease beyond a bias of ≈ 0.2 eV due to scattering of conduction electrons from a population of high frequency phonons [5][6][7][8]. Under bias voltage, the process of electron scattering excites new phonons into this population an order of magnitude faster than their decay via thermalisation [9].…”

mentioning

confidence: 99%

“…tal and theoretical studies show that electronic transport in metallic CNTs undergoes a dramatic decrease beyond a bias of ≈ 0.2 eV due to scattering of conduction electrons from a population of high frequency phonons. [5][6][7][8] Under bias voltage, the process of electron scattering excites new phonons into this population an order of magnitude faster than their decay via thermalisation. 9 This dominance of excitation over deexcitation results in a growing population of athermal "hot" phonons and consequently a non-equilibrium phonon distribution.…”

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confidence: 99%

Encapsulated nanowires: Boosting electronic transport in carbon nanotubes

et al. 2017

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The electrical conductivity of metallic carbon nanotubes (CNTs) quickly saturates with respect to bias voltage due to scattering from a large population of optical phonons. Decay of these dominant scatterers in pristine CNTs is too slow to offset an increased generation rate at high voltage bias. We demonstrate from first principles that encapsulation of 1D atomic chains within a single-walled CNT can enhance decay of "hot" phonons by providing additional channels for thermalisation. Pacification of the phonon population growth reduces electrical resistivity of metallic CNTs by 51% for an example system with encapsulated beryllium.Carbon Nanotubes (CNTs) are the most promising candidates for nanoelectronics applications due to their excellent electrical conductivity [1][2][3]. With these properties applied in integrated circuits and in the field effect transistors' gate electrodes metallic CNTs lead the minituarisation race at the nanoscale [4]. However experimental and theoretical studies show that electronic transport in metallic CNTs undergoes a dramatic decrease beyond a bias of ≈ 0.2 eV due to scattering of conduction electrons from a population of high frequency phonons [5][6][7][8]. Under bias voltage, the process of electron scattering excites new phonons into this population an order of magnitude faster than their decay via thermalisation [9]. This dominance of excitation over deexcitation results in a growing population of athermal "hot" phonons and consequently a non-equilibrium phonon distribution [10,11]. Under such conditions, these hot phonons constitute the dominant source of electron scattering, and hence resistivity, in metallic CNTs. A mechanism for increasing the rate of phonon thermalisation will therefore enhance the electrical performance of CNTs.The process of phonon deexcitation involves anharmonic phonon-phonon scattering, hence its rate is dependent on the number of available channels for phonon decay. Previously, several possible solutions for introduction of additional thermalisation channels were suggested that considered a supporting substrate or isotopic disorder [12][13][14].In this letter we show that reduction of the hot phonon population under bias is readily achievable via encapsulation of 1D nanowires in single-walled CNTs (SWCNT). We consider phonon-phonon relaxation from first principles and demonstrate that an encapsulated one-dimensional crystal creates additional channels for hot phonon thermalisation, increasing the decay rate. This results in a significant improvement of the voltage-current ratio at high bias voltage. Transport is studied by solving the set of parameter-free Boltzmann transport equations (BTE) for coupled dynamics of electrons and phonons, whilst all relevant scattering rates are calculated ab initio with densityfunctional perturbational theory (DFPT). This route to enhanced transport is attractive due to increasingly well-established methods for growth of 1D crystals inside CNTs [15][16][17][18][19] and assembly of nanowires into integrated devices [...

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“…By contrast, highfield measurements carried out on suspended carbon nanotubes (CNTs) had previously revealed a wealth of new physical phenomena, including negative differential conductance, 14,15 thermal light emission, 16 and the presence of non-equilibrium optical phonons. 14,17 In this letter we examine the intrinsic transport properties of suspended graphene devices at high fields and high temperatures. This approach enables us to extract both the drift (saturation) velocity of charge carriers and the thermal conductivity of graphene up to higher temperatures than previously possible (>1000 K).…”

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confidence: 99%

High-Field Electrical and Thermal Transport in Suspended Graphene

Dorgan¹,

Behnam²,

et al. 2013

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We study the intrinsic transport properties of suspended graphene devices at high fields (≥1 V/μm) and high temperatures (≥1000 K). Across 15 samples, we find peak (average) saturation velocity of 3.6 × 10(7) cm/s (1.7 × 10(7) cm/s) and peak (average) thermal conductivity of 530 W m(-1) K(-1) (310 W m(-1) K(-1)) at 1000 K. The saturation velocity is 2-4 times and the thermal conductivity 10-17 times greater than in silicon at such elevated temperatures. However, the thermal conductivity shows a steeper decrease at high temperature than in graphite, consistent with stronger effects of second-order three-phonon scattering. Our analysis of sample-to-sample variation suggests the behavior of "cleaner" devices most closely approaches the intrinsic high-field properties of graphene. This study reveals key features of charge and heat flow in graphene up to device breakdown at ~2230 K in vacuum, highlighting remaining unknowns under extreme operating conditions.

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Anomalous kink behavior in the current-voltage characteristics of suspended carbon nanotubes

Cited by 16 publications

References 23 publications

Competing Photocurrent Mechanisms in Quasi‐Metallic Carbon Nanotube pn Devices

Competing Photocurrent Mechanisms in Quasi‐Metallic Carbon Nanotube pn Devices

Encapsulated nanowires: Boosting electronic transport in carbon nanotubes

High-Field Electrical and Thermal Transport in Suspended Graphene

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