Collective transport in arrays of small metallic dots

Middleton, A. Alan; Wingreen, Ned S.

doi:10.1103/physrevlett.71.3198

Cited by 404 publications

(555 citation statements)

References 16 publications

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“…From the fits, we obtain α = 3.1, 3.3 and 3.4 at 4.2 K, 10 K, and 15 K respectively. For a twodimensional array of nanoparticles, the theoretical value of α was predicted as 1.6 while numerical simulations yielded as 2.0 [29]. However, in previous experimental studies of two dimensional metal nanocrystal arrays, the exponent α was reported to vary from 2 to 2.5 which depends on size distribution, while for quasi 2D system with multilayered nanoparticles the value was 2.6 to 3.0 [30][31][32][33][34].…”

Section: Theoretical Studies Of Qd Arrays By Middleton and Wingreen (mentioning

confidence: 99%

“…where E c is charging energy of a QD, β is a prefactor whose value depends on the dimensionality and arrays geometry (for a 2D array β = 0.3), and N is the number 7 of QDs in the conduction path [29,37]. From here, we can estimate the number of GQDs in our array contributing in the charge transport, however, we need to estimate E c first.…”

Section: Theoretical Studies Of Qd Arrays By Middleton and Wingreen (mentioning

confidence: 99%

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Coulomb blockade and hopping conduction in graphene quantum dots array

2011

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We show that the low temperature electron transport properties of chemically functionalized graphene can be explained as sequential tunneling of charges through a two dimensional array of graphene quantum dots (GQD). Below 15 K, a total suppression of current due to Coulomb blockade through GQD array was observed. Temperature dependent current-gate voltage characteristics show Coulomb oscillationswith energy scales of 6.2-10 meV corresponding to GQD sizes of 5-8 nm while resistance data exhibit an Efros-Shklovskii variable range hopping arising from structural and size induced disorder.

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Section: Theoretical Studies Of Qd Arrays By Middleton and Wingreen (mentioning

confidence: 99%

Section: Theoretical Studies Of Qd Arrays By Middleton and Wingreen (mentioning

confidence: 99%

Coulomb blockade and hopping conduction in graphene quantum dots array

2011

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“…Research on electronic properties of porous materials includes theoretical work on quantum percolation, [8][9][10] which applies when porosity has an atomic length scale, and studies of Coulomb-blockaded semiclassical transport on porous lattices that reveals analogies with phase transitions. [11][12][13] In the present paper, we study the diffusion of photogenerated electrons in mesoporous titania. The electrolyte, which fills the pores, is not only essential to the application of this material in solar cells, but also appears to passivate defects that greatly retard electron transport in "dry" mesoporous titania.…”

Section: Introductionmentioning

confidence: 99%

Temperature dependence of the electron diffusion coefficient in electrolyte-filledTiO2nanoparticle films: Evidence against multiple trapping in exponential conduction-band tails

et al. 2006

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The temperature and photoexcitation density dependences of the electron transport dynamics in electrolytefilled mesoporous TiO 2 nanoparticle films were investigated by transient photocurrent measurements. The thermal activation energy of the diffusion coefficient of photogenerated electrons ranged from 0.19-0.27 eV, depending on the specific sample studied. The diffusion coefficient also depends strongly on the photoexcitation density; however, the activation energy has little, if any, dependence on the photoexcitation density. The light intensity dependence can be used to infer temperature-independent dispersion parameters in the range 0.3-0.5. These results are inconsistent with the widely used transport model that assumes multiple trapping of electrons in an exponential conduction-band tail. We can also exclude a model allowing for widening of a band tail with increased temperature. Our results suggest that structural, not energetic, disorder limits electron transport in mesoporous TiO 2 . The analogy between this material and others in which charge transport is limited by structural disorder is discussed.

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“…In the presence of both charge and structural disorder this interplay leads to highly nonOhmic current-voltage (I-V) characteristics. Coulomb blockade theory predicts that at low temperatures, there is no current below a specific threshold voltage, V t , while above V t the current follows a power law:with ζ ~ 1 in one dimensional (1D) and 5/3 or 2 in twodimensional (2D) systems [2]. V t depends on the nanocrystal number, the capacitance of the conducting regions and the capacitance between the each region and the back gate.…”

mentioning

confidence: 99%

“…with ζ ~ 1 in one dimensional (1D) and 5/3 or 2 in twodimensional (2D) systems [2]. V t depends on the nanocrystal number, the capacitance of the conducting regions and the capacitance between the each region and the back gate.…”

mentioning

confidence: 99%

Coulomb-blockade transport in quasi-one-dimensional polymer nanofibers

et al. 2005

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We report the low temperature current-voltage (I-V) characteristics studies in quasi one-dimensional conducting polymer nanofibers. We find a threshold voltage V t below which little current flows at temperatures below 30 -40 K. For V > V t current scales as (V/V t -1) ζ , where ζ ~ 1.8 -2.1 at high biases. Differential conductance oscillations are observed whose magnitude increases as temperature decreases below 10 K. We attributed the observed low temperature I-V behavior to Coulomb blockade effects with a crossover to Luttinger liquid-like behavior at high temperature. We demonstrate that at low temperatures such a doped conjugated polymer fiber can be considered as an array of small conducting regions separated by nanoscale barriers, where the Coulomb blockade tunneling is the dominant transport mechanism.PACS numbers: 71.30.+h, 72.20.Ee, 72.80.Le Complex structures built of nanosize conducting objects provide model systems for investigation of transport phenomena on the mesoscopic scale, where quantum confinement and Coulomb charging play an important role [1]. Electronic transport through an array of metallic nanocrystals separated by nanobarriers is determined by the interplay between single-electron charging of an individual conducting region and tunneling between adjacent islands. In such systems both the tunneling resistance between neighboring regions is large, R T >> h/e 2 and the charging energy E C = e 2 /2C of an excess electron on a site is larger than k B T (C is the capacitance of the region). In the presence of both charge and structural disorder this interplay leads to highly nonOhmic current-voltage (I-V) characteristics. Coulomb blockade theory predicts that at low temperatures, there is no current below a specific threshold voltage, V t , while above V t the current follows a power law:with ζ ~ 1 in one dimensional (1D) and 5/3 or 2 in twodimensional (2D) systems [2]. V t depends on the nanocrystal number, the capacitance of the conducting regions and the capacitance between the each region and the back gate. Such a behavior with scaling exponents between 1 and 2.3 has been found, for example, in narrow chains of carbon nanoparticles [3], and in 100 nm wide multilayer of gold particles which exhibited ζ ~ 1.6 [4]. Coulomb-blockade effects have also been observed in multiwalled carbon nanotubes [5], organic thin-film transistors based on highly ordered molecular materials [6] as well as in single-molecular transistor structures [7]. It is evident that the nature of the individual regions: metallic, semiconducting, quantum dots -is irrelevant for this phenomenon to be observed [8]. In view of these results the question arises whether Coulomb-blockade effects can also be observed in such inherent quasi-1D systems as conducting polymer nanofibers. In this connection polyacetylene (PA) nanofibers are of particular interest as the model system for nanotransport studies because of the simple chemical structure, well defined polycrystallinity [9], and good ability for doping [10][11][12]. It is...

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Collective transport in arrays of small metallic dots

Cited by 404 publications

References 16 publications

Coulomb blockade and hopping conduction in graphene quantum dots array

Coulomb blockade and hopping conduction in graphene quantum dots array

Temperature dependence of the electron diffusion coefficient in electrolyte-filledTiO2nanoparticle films: Evidence against multiple trapping in exponential conduction-band tails

Coulomb-blockade transport in quasi-one-dimensional polymer nanofibers

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