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Quantum capacitance

About: Quantum capacitance is a(n) research topic. Over the lifetime, 954 publication(s) have been published within this topic receiving 24165 citation(s). more


Open accessJournal ArticleDOI: 10.1126/SCIENCE.AAB3798
Tianquan Lin1, I-Wei Chen2, Fengxin Liu1, Chongyin Yang1  +4 moreInstitutions (3)
18 Dec 2015-Science
Abstract: Carbon-based supercapacitors can provide high electrical power, but they do not have sufficient energy density to directly compete with batteries. We found that a nitrogen-doped ordered mesoporous few-layer carbon has a capacitance of 855 farads per gram in aqueous electrolytes and can be bipolarly charged or discharged at a fast, carbon-like speed. The improvement mostly stems from robust redox reactions at nitrogen-associated defects that transform inert graphene-like layered carbon into an electrochemically active substance without affecting its electric conductivity. These bipolar aqueous-electrolyte electrochemical cells offer power densities and lifetimes similar to those of carbon-based supercapacitors and can store a specific energy of 41 watt-hours per kilogram (19.5 watt-hours per liter). more

Topics: Supercapacitor (59%), Carbon (55%), Electrochemical cell (53%) more

1,425 Citations

Journal ArticleDOI: 10.1038/NNANO.2009.177
Jilin Xia1, Fang Chen1, Jinghong Li2, Nongjian Tao1Institutions (2)
Abstract: Graphene has received widespread attention due to its unique electronic properties. Much of the research conducted so far has focused on electron mobility, which is determined by scattering from charged impurities and other inhomogeneities. However, another important quantity, the quantum capacitance, has been largely overlooked. Here, we report a direct measurement of the quantum capacitance of graphene as a function of gate potential using a three-electrode electrochemical configuration. The quantum capacitance has a non-zero minimum at the Dirac point and a linear increase on both sides of the minimum with relatively small slopes. Our findings -- which are not predicted by theory for ideal graphene -- suggest that charged impurities also influences the quantum capacitance. We also measured the capacitance in aqueous solutions at different ionic concentrations, and our results strongly indicate that the long-standing puzzle about the interfacial capacitance in carbon-based electrodes has a quantum origin. more

Topics: Quantum capacitance (73%), Electric Capacitance (66%), Differential capacitance (65%) more

1,307 Citations

Journal ArticleDOI: 10.1063/1.99649
Abstract: Two‐dimensional electron gas (2DEG) in a quantum well or inversion layer, unlike an ordinary grounded metallic plane, does not completely screen an applied transverse electric field. Owing to its Fermi degeneracy energy, a 2DEG manifests itself as a capacitor in series, whose capacitance per unit area equals CQ=me2/πℏ2, where m is the effective electron mass in the direction transverse to the quantum well. Partial penetration of an external field through a highly conducting 2DEG allows the implementation of several novel high‐speed devices, including a three‐terminal resonant‐tunneling transistor and a gate‐controlled thermionic emission transistor. more

Topics: Quantum capacitance (58%), Capacitance (56%), Field-effect transistor (55%) more

730 Citations

Journal ArticleDOI: 10.1109/TED.2003.815366
Abstract: Numerical simulations are used to guide the development of a simple analytical theory for ballistic field-effect transistors. When two-dimensional (2-D) electrostatic effects are small (and when the insulator capacitance is much less than the semiconductor (quantum) capacitance), the model reduces to Natori's theory of the ballistic MOSFET. The model also treats 2-D electrostatics and the quantum capacitance limit where the semiconductor quantum capacitance is much less than the insulator capacitance. This new model provides insights into the performance of MOSFETs near the scaling limit and a unified framework for assessing and comparing a variety of novel transistors. more

Topics: Quantum capacitance (63%), Capacitance (60%), MOSFET (51%) more

687 Citations

Open accessJournal ArticleDOI: 10.1063/1.2776887
Abstract: In this work, fundamental results for carrier statistics in graphene two-dimensional sheets and nanoscale ribbons are derived. Though the behavior of intrinsic carrier densities in two-dimennsional graphene sheets is found to differ drastically from traditional semiconductors, very narrow (sub-10nm) ribbons are found to be similar to traditional narrow-gap semiconductors. The quantum capacitance, an important parameter in the electrostatic design of devices, is derived for both two-dimensional graphene sheets and nanoribbons. more

Topics: Graphene nanoribbons (67%), Quantum capacitance (59%), Graphene (58%) more

604 Citations

No. of papers in the topic in previous years

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Topic's top 5 most impactful authors

Kosuke Nagashio

11 papers, 234 citations

Steven J. Koester

10 papers, 142 citations

Deji Akinwande

9 papers, 225 citations

Razali Ismail

9 papers, 62 citations

Mona A. Ebrish

6 papers, 85 citations

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