Enhancing thermoelectric properties of graphene quantum rings

Saiz-Bretín, M.; Малышев, А. В.; Orellana, P. A.; Domı́nguez-Adame, F.

doi:10.1103/physrevb.91.085431

Cited by 44 publications

(47 citation statements)

References 34 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…To understand the observed smoothening of the conductance plateaus we also carried out numerical simulations within the nearest neighbor tight-binding approach for p z electrons of C atoms in graphene. [9,10,26,27] Simulations of GNCs samples without edge roughness do not show abrupt plateaus which, however, are revealed in long GNRs. The good agreement between theory and experiment leads us to the conclusion that quantum interference is responsible for the smooth plateaus observed in the conductance while edge disorder does not play any relevant role.…”

Section: Introductionmentioning

confidence: 93%

Quantized Electron Transport Through Graphene Nanoconstrictions

Clericò

Delgado-Notario

Saiz-Bretín

et al. 2018

Physica Status Solidi (a)

View full text Add to dashboard Cite

Here, the quantization of Dirac fermions in lithographically defined graphene nanoconstrictions is studied. Quantized conductance is observed in single nanoconstrictions fabricated on top of a thin hexamethyldisilazane layer over a Si/SiO2 wafer. This nanofabrication method allows to obtain well defined edges in the nanoconstrictions, thus reducing the effects of edge roughness on the conductance. The occurrence of ballistic transport is proved and several size quantization plateaus are identified in the conductance at low temperature. Experimental data and numerical simulations show good agreement, demonstrating that the smoothening of the plateaus is not related to edge roughness but to quantum interference effects.

show abstract

Section: Introductionmentioning

confidence: 93%

Quantized Electron Transport Through Graphene Nanoconstrictions

Clericò

Delgado-Notario

Saiz-Bretín

et al. 2018

Physica Status Solidi (a)

View full text Add to dashboard Cite

show abstract

“…For more complex geometries, the Hamiltonian should be numerically diagonalized. For this purpose, a convenient approach is the quantum transmitting boundary method, which can deal with small conductors of arbitrary shape and couplings [207] and has been recently applied to thermoelectric transport [58,208].…”

Section: Electron Transport In Nanowiresmentioning

confidence: 99%

Nanowires: A route to efficient thermoelectric devices

Domı́nguez-Adame

Martín‐González

Sánchez

et al. 2019

Physica E: Low-dimensional Systems and Nanostructures

View full text Add to dashboard Cite

Miniaturization of electronic devices aims at manufacturing ever smaller products, from mesoscopic to nanoscopic sizes. This trend is challenging because the increased levels of dissipated power demands a better understanding of heat transport in small volumes. A significant amount of the consumed energy in electronics is transformed into heat and dissipated to the environment. Thermoelectric materials offer the possibility to harness dissipated energy and make devices less energy-demanding. Heat-to-electricity conversion requires materials with a strongly suppressed thermal conductivity but still high electronic conduction. Nanowires can meet nicely these two requirements because enhanced phonon scattering at the surface and defects reduces the lattice thermal conductivity while electric conductivity is not deteriorated, leading to an overall remarkable thermoelectric efficiency. Therefore, nanowires are regarded as a promising route to achieving valuable thermoelectric materials at the nanoscale. In this paper, we present an overview of key experimental and theoretical results concerning the thermoelectric properties of nanowires. The focus of this review is put on the physical mechanisms by which the efficiency of nanowires can be improved. Phonon scattering at surfaces and interfaces, enhancement of the power factor by quantum effects and topological protection of electron states to prevent the degradation of electrical conductivity in nanowires are thoroughly discussed.

show abstract

“…One expects that the interedge coupling of states and enhanced size effects in a GQR will lead to some new physical properties, therefore, it may be one of the most novel building blocks for future nanodevices. Currently, there are several groups contributing their work to studies of GQRs, either experimentally [5,16,17] or theoretically [18][19][20][21][22][23][24]. The experimental investigations mainly focus on external magnetically induced Aharonov-Bohm (AB) effects [5,16,17] and Shubnikov-de Haas (SdH) oscillations [16] in GQRs, and theoretical studies basically concentrate on using the usual tight-binding (TB) model to explore the AB oscillation [18][19][20], persistent currents [21], and energy spectra as a function of the magnetic flux [22].…”

Section: Introductionmentioning

confidence: 99%