Measurement of electronic heat dissipation in highly disordered graphene

Hemsworth, N.; Mahvash, Farzaneh; Lévesque, Pierre L.; Siaj, Mohamed; Martel, Richard; Szkopek, Thomas

doi:10.1103/physrevb.92.241411

Cited by 6 publications

(9 citation statements)

References 34 publications

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“…1a) for the representative sample HG18. Strong insulating behaviour, ∂R 2pt /∂T < 0, is observed, indicative of the onset of electron localization by the introduction of neutral point defects into the graphene lattice via hydrogenation, as previously reported [3,4,24,26]. The field effect corresponds to hole conduction, ∂R 2pt /∂V G > 0, with a field effect mobility µ ∝ ∂(1/R)/∂V G → 0 as T → 0.…”

supporting

confidence: 77%

“…Atomic hydrogen adsorbates create C-H bonds that disrupt the sp 2 lattice of graphene to create localized sp 3 distortions, with a profound effect on graphene's electronic properties [24,25]. The neutral point defect density per carbon atom induced by hydrogenation in our samples is on the order of parts per thousand, as inferred from Raman spectroscopy [3,4,26]. Direct experimental evidence for band gap opening and the appearance of localized states in hydrogenated graphene has reported using angle-resolved photoemission spectroscopy (ARPES) and scanning tunnelling spectroscopy [28][29][30][31].…”

mentioning

confidence: 83%

“…The model of Matveev et al assumes a constant density of localized states, thus leading to a temperature dependent conductivity σ xx = σ 0 exp −(T /T 0 ) 1/d+1 F (x) , where d = 2, 3 is the dimension of the conductor, T 0 is the characteristic Mott temperature, and F (x) is a universal function of a dimensionless magnetic field parameter x = µ B B/k B T (T 0 /T ) 1/d+1 . Experimentally measured hydrogenated graphene resistivity does not follow a simple Mott variable range hopping law [3,4,26] (see Supplemental Material [33]). The measured resistance of HGT2 in logarithmic scale versus reciprocal temperature 1/T at zero magnetic field is shown in Fig.…”

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confidence: 99%

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Large magnetoresistance by Pauli blockade in hydrogenated graphene

et al. 2018

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We report the observation of a giant positive magnetoresistance in millimetre scale hydrogenated graphene with magnetic field oriented in the plane of the graphene sheet. A positive magnetoresistance in excess of 200% at a temperature of 300 mK was observed in this configuration, reverting to negative magnetoresistance with the magnetic field oriented normal to the graphene plane. We attribute the observed positive, in-plane, magnetoresistance to Pauli-blockade of hopping conduction induced by spin polarization. Our work shows that spin polarization in concert with electron-electron interaction can play a dominant role in magnetotransport within an atomic monolayer.

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confidence: 77%

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confidence: 83%

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confidence: 99%

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Large magnetoresistance by Pauli blockade in hydrogenated graphene

et al. 2018

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“…[5][6][7][8][9] The energy loss can occur through the emission of several types of phonons depending on the temperature range. Longitudinal and transverse types of acoustic, [8,13] optic, [14][15][16] substrate surface, [17,18] piezoelectric, [19,20] and flexural phononic modes can appear as modes of el-ph scattering [12] under different environments (suspended, substrated, etc.) and different transport regimes (Bloch-Gruneisen, Equipartition, etc.).…”

Section: Introductionmentioning

confidence: 99%

“…A limited number of studies in BLG for hot electron cooling are theoretically investigated. [38,39] There are many theoretical methods apart from simulation [40] (such as Boltzmann Transport theory, [11,23] Green's function-based Kubo method, [16] and the hydrodynamic approach [3,41] ) are used to explain electron transport properties of the disordered materials. Among these approaches, the simplest one is that of Boltzmann transport theory, which treats the scattering of electrons within the Fermi golden rule, but it is suitable only for a pure system in thermal equilibrium and for scattering from charged impurities.…”

Section: Introductionmentioning

confidence: 99%

Energy Relaxation and Cooling in Impure Bilayer Graphene at Low Temperatures

Obaidurrahman

Ashraf

2022

Physica Status Solidi (b)

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Understanding the physical mechanism of heat dissipation is a matter of increasing concern from the perspective of waste heat management in nanostructure‐based devices. The impurity‐driven electron–phonon scattering is a significant channel for energy relaxation in graphene and its bilayer. The recently developed Keldysh formalism for single‐layer graphene (SLG) is extended to investigate the transport phenomena due to phonon interaction via the deformation potential in disordered bilayer graphene (BLG) at low temperatures within the impure limit, . It is observed that in the BLG system also, the temperature dependence of the relaxation rate and the cooling power are affected by the occurrence of disorder and screening, with the temperature exponent of pure BLG modified to in impure BLG. A comparison with the temperature and mean free path exponents of SLG reveals that the exponents in BLG turn out to be the same, but they both differ from the conventional 2DEG. However, the magnitude of the scattering rate and cooling power is more pronounced in BLG in a low‐temperature regime. As the magnitude of the relaxation rate and the cooling rate varies with impurity, the impurity‐assisted electron–phonon scattering has rich implications on hot carrier transport in BLG devices.

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Supercollision cooling effects on the hot photoluminescence emission of graphene

2016

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We report on hot photoluminescence measurements that show the effects of acoustic phonon supercollision processes in the intensity of graphene light emission. We use a simple optical method to induce defects on single layer graphene in a controlled manner to study in detail the light emission dependence on the sample defect density. It is now well accepted that the graphene photoluminescence is due to black-body thermal emission from the quasi-equilibrium electrons at a temperature well above the lattice temperature. Our results show that as the sample defect density is increased the electrons relax energy more efficiently via acoustic phonon supercollision processes leading to lower electron temperatures and thus lower emission intensities. The calculated intensity decrease due to supercollision energy relaxation agrees well with the experimental data.

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Measurement of electronic heat dissipation in highly disordered graphene

Cited by 6 publications

References 34 publications

Large magnetoresistance by Pauli blockade in hydrogenated graphene

Large magnetoresistance by Pauli blockade in hydrogenated graphene

Energy Relaxation and Cooling in Impure Bilayer Graphene at Low Temperatures

Supercollision cooling effects on the hot photoluminescence emission of graphene

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