Phonon-Assisted Resonant Tunneling of Electrons in Graphene–Boron Nitride Transistors

Вдовин, Е. Е.; Mishchenko, Artem; Greenaway, M. T.; Zhu, Mengjian; Ghazaryan, Davit; Misra, Abhishek; Cao, Yang; Морозов, С. В.; Makarovsky, O.; Fromhold, T. M.; Patanè, A.; Slotman, Guus J.; Katsnelson, M. I.; Geǐm, A. K.; Новоселов, К. С.; Eaves, L.

doi:10.1103/physrevlett.116.186603

Cited by 85 publications

(86 citation statements)

References 36 publications

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“…At typical device operated at room temperature and above, electrons in graphene are expected to undergo strong scatterings with phonons and impurities. Thus, at the high-temperature thermionic emission regime, kconservation is expected to be strongly violated due to phonon [29] and impurity scattering [30] effects, which immediately implies the breakdown of assumption (i). Secondly, as the interface potential exceeds Φ B ≈ 1 eV, the thermionic emission should be dominantly contributed by energetic carriers with ε > 1 eV, where the band structure deviates significantly from the simple Dirac cone approximation.…”

Section: Introductionmentioning

confidence: 99%

Generalized High-Energy Thermionic Electron Injection at Graphene Interface

et al. 2019

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Graphene thermionic electron emission across high-interface-barrier involves energetic electrons residing far away from the Dirac point where the Dirac cone approximation of the band structure breaks down. Here we construct a full-band model beyond the simple Dirac cone approximation for the thermionic injection of high-energy electrons in graphene. We show that the thermionic emission model based on the Dirac cone approximation is valid only in the graphene/semiconductor Schottky interface operating near room temperature, but breaks down in the cases involving highenergy electrons, such as graphene/vacuum interface or heterojunction in the presence of photon absorption, where the full-band model is required to account for the band structure nonlinearity at high electron energy. We identify a critical barrier height, Φ (c) B ≈ 3.5 eV, beyond which the Dirac cone approximation crosses over from underestimation to overestimation. In the high-temperature thermionic emission regime at graphene/vacuum interface, the Dirac cone approximation severely overestimates the electrical and heat current densities by more than 50% compared to the more accurate full-band model. The large discrepancies between the two models are demonstrated using a graphene-based thermionic cooler. These findings reveal the fallacy of Dirac cone approximation in the thermionic injection of high-energy electrons in graphene. The full-band model developed here can be readily generalized to other 2D materials, and shall provide an improved theoretical avenue for the accurate analysis, modeling and design of graphene-based thermionic energy devices.

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Section: Introductionmentioning

confidence: 99%

Generalized High-Energy Thermionic Electron Injection at Graphene Interface

et al. 2019

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“…Recently, several papers have examined inelastic signals due to vibrational excitations in the second derivative of the current-voltage characteristics, so-called inelastic electron transport spectroscopy (IETS), of gated pristine graphene [22][23][24][25][26][27], and heterostructures of graphene and hexagonal boron nitride [28,29]. With the rapid development in fabrication and electronic characterization of nanostructured graphene [19,20,30] it is interesting to investigate the presence of inelastic vibrational signals for GNCs.…”

Section: Introductionmentioning

confidence: 99%

Inelastic vibrational signals in electron transport across graphene nanoconstrictions

et al. 2016

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We present calculations of the inelastic vibrational signals in the electrical current through a graphene nanoconstriction. We find that the inelastic signals are only present when the Fermi-level position is tuned to electron transmission resonances, thus, providing a fingerprint which can link an electron transmission resonance to originate from the nanoconstriction. The calculations are based on a novel first-principles method which includes the phonon broadening due to coupling with phonons in the electrodes. We find that the signals are modified due to the strong coupling to the electrodes, however, still remain as robust fingerprints of the vibrations in the nanoconstriction. We investigate the effect of including the full self-consistent potential drop due to finite bias and gate doping on the calculations and find this to be of minor importance.

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“…There is also significant interest in Gr/BN/Gr heterostructures for electronic device applications [14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30][31][32][33] . Gr/BN/Gr structures display negative differential resistance (NDR), 20,24,27,[30][31][32]34 and theoretical calculations predict maximum frequencies of several hundred GHz.…”

Section: Introductionmentioning

confidence: 99%

“…Gr/BN/Gr structures display negative differential resistance (NDR), 20,24,27,[30][31][32]34 and theoretical calculations predict maximum frequencies of several hundred GHz. 26 The NDR arises from the line-up of the source and drain graphene Dirac cones combined with the conservation of in-plane momentum.…”

Section: Introductionmentioning

confidence: 99%

Interlayer transport through a graphene/rotated boron nitride/graphene heterostructure

Habib

et al. 2017

Phys. Rev. B

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Interlayer electron transport through a graphene / hexagonal boron-nitride (h-BN) / graphene heterostructure is strongly affected by the misorientation angle θ of the h-BN with respect to the graphene layers with different physical mechanisms governing the transport in different regimes of angle, Fermi level, and bias. The different mechanisms and their resulting signatures in resistance and current are analyzed using two different models, a tight-binding, non-equilibrium Green function model and an effective continuum model, and the qualitative features resulting from the two different models compare well. In the large-angle regime (θ > 4• ), the change in the effective h-BN bandgap seen by an electron at the K point of the graphene causes the resistance to monotonically increase with angle by several orders of magnitude reaching a maximum at θ = 30• . It does not affect the peak-to-valley current ratios in devices that exhibit negative differential resistance. In the small-angle regime (θ < 4• ), Umklapp processes open up new conductance channels that manifest themselves as non-monotonic features in a plot of resistance versus Fermi level that can serve as experimental signatures of this effect. For small angles and high bias, the Umklapp processes give rise to two new current peaks on either side of the direct tunneling peak.

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Phonon-Assisted Resonant Tunneling of Electrons in Graphene–Boron Nitride Transistors

Cited by 85 publications

References 36 publications

Generalized High-Energy Thermionic Electron Injection at Graphene Interface

Generalized High-Energy Thermionic Electron Injection at Graphene Interface

Inelastic vibrational signals in electron transport across graphene nanoconstrictions

Interlayer transport through a graphene/rotated boron nitride/graphene heterostructure

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