scispace - formally typeset
Search or ask a question
Topic

Quantum capacitance

About: Quantum capacitance is a research topic. Over the lifetime, 954 publications have been published within this topic receiving 24165 citations.


Papers
More filters
Journal ArticleDOI
TL;DR: In this paper, the ballistic current of n-MOSFETs was analyzed as a function of the transport direction, the channel material, and the technological parameters, and it was shown that the use of channel materials with very small transport masses implies a tradeoff between the electron velocity and the gate drive capacitance, because of the finite capacitance of the inversion layer.
Abstract: This paper presents new analytical derivations for the ballistic current of n-MOSFETs as a function of the transport direction, of the properties of the channel material, and of the technological parameters. The main purpose of the analytical expressions is to provide an insight into the optimization of the transistors with alternative channel materials. Our results simply explain why, for a given two-dimensional (2-D) density of states, an elliptic 2-D minimum can provide a current larger than a circular minimum if the best transport direction is selected. Furthermore, we analytically show that the use of channel materials with very small transport masses implies a tradeoff between the electron velocity and the gate drive capacitance, because of the finite capacitance of the inversion layer. This latter effect should be seriously considered in the context of the aggressive scaling of the equivalent oxide thickness enforced by the introduction of high-K dielectrics and multigate MOSFETs

46 citations

Journal ArticleDOI
TL;DR: In this paper, it was shown that at finite frequency, a quantum capacitance can be characterized by a classical $RLC$ circuit with three parameters: a static electrochemical capacitance, a charge relaxation resistance, and a quantum inductance.
Abstract: We report on theoretical investigations of frequency-dependent quantum capacitance. It is found that at finite frequency, a quantum capacitor can be characterized by a classical $RLC$ circuit with three parameters: a static electrochemical capacitance, a charge relaxation resistance, and a quantum inductance. The quantum inductance is proportional to the characteristic time scale of electron dynamics, and due to its existence, the time-dependent current can accumulate a phase delay and lags behind the applied ac voltage, leading to a negative effective capacitance.

45 citations

Journal ArticleDOI
TL;DR: In this paper, the effects of co-doping of transition metal (Mn, Fe, Co, Ni) and N atoms on the structural stability, quantum capacitance and surface storage charge of graphene using density functional theory calculations were explored.

45 citations

Journal ArticleDOI
TL;DR: The lesser diffusion energy barrier for K+ ions of the K2SO4 electrolyte in the NiCo2O4 layer contributes toward higher energy storage capacity, and can serve as a high-performance electrode material for supercapacitor applications.
Abstract: In this work, we demonstrated the supercapacitor performance of pristine and composites of spinel NiCo2O4 with a multi-walled carbon nanotube (MWCNT) assembled in a two-electrode cell configuration. Spinel NiCo2O4 and NiCo2O4@MWCNT composites were synthesized via a facile hydrothermal method. The supercapacitive performance of as-synthesized NiCo2O4 and NiCo2O4@MWCNT fabricated on Ni-foam was studied in a 0.5M K2SO4 electrolyte using electrochemical measurement techniques. The symmetric cell configuration of NiCo2O4@MWCNT delivers high specific capacitance (374 F/g at 2 A/g) with high energy density and power density (95 Wh/kg and 3 964 W/kg, respectively) compared to that of pristine NiCo2O4 electrodes (137 F/g at 0.6 A/g). Furthermore, the energy storage performance of the asymmetric cells of NiCo2O4//MWCNT and NiCo2O4@MWCNT//MWCNT was studied to enhance cycling stability (retention of 74.85% over 3000 cycles). We have also theoretically studied the supercapacitance performance of pristine NiCo2O4 and NiCo2O4@SWCNT hybrid structures through its structural and electronic properties using density functional theory predictions. The higher specific capacitance of the NiCo2O4@SWCNT hybrid system with high power density and energy density is supported by the enhanced density of states near the Fermi level and increased quantum capacitance of the hybrid structure. We have theoretically computed the diffusion energy barrier of K+ ions of the K2SO4 electrolyte in the NiCo2O4 layer and compared it with the diffusion barrier for Na+ ions. The lesser diffusion energy barrier for K+ ions in the NiCo2O4 layer contributes toward higher energy storage capacity. Thus, owing to superior electrochemical performance of NiCo2O4 composites with MWCNTs, it can serve as a high-performance electrode material for supercapacitor applications.

45 citations

Journal ArticleDOI
TL;DR: In this article, the authors reported the existence of quantum capacitance or electrochemical capacitance like phenomenon effect in the improvement of the performance of the DSSC device in the presence of Au nanoparticles.

44 citations


Network Information
Related Topics (5)
Silicon
196K papers, 3M citations
85% related
Quantum dot
76.7K papers, 1.9M citations
85% related
Band gap
86.8K papers, 2.2M citations
85% related
Graphene
144.5K papers, 4.9M citations
83% related
Thin film
275.5K papers, 4.5M citations
83% related
Performance
Metrics
No. of papers in the topic in previous years
YearPapers
202331
202238
202162
202062
201965
201858