Abstract
Ionic-liquid gates have a high carrier density due to their atomically thin electric double layer (EDL) and extremely large geometrical capacitance C g. However, a high carrier density in graphene has not been achieved even with ionic-liquid gates because the EDL capacitance C EDL between the ionic liquid and graphene involves the series connection of C g and the quantum capacitance C q, which is proportional to the density of states. We investigated the variables that determine C EDL at the molecular level by varying the number of graphene layers n and thereby optimising C q. The C EDL value is governed by C q at n <4, and by C g at n > 4. This transition with n indicates a composite nature for C EDL. Our finding clarifies a universal principle that determines capacitance on a microscopic scale, and provides nanotechnological perspectives on charge accumulation and energy storage using an ultimately thin capacitor.
| Original language | English |
|---|---|
| Article number | 1595 |
| Journal | Scientific Reports |
| Volume | 3 |
| DOIs | |
| Publication status | Published - 2013 |
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ASJC Scopus subject areas
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Cite this
Electric double-layer capacitance between an ionic liquid and few-layer graphene. / Uesugi, Eri; Goto, Hidenori; Eguchi, Ritsuko; Fujiwara, Akihiko; Kubozono, Yoshihiro.
In: Scientific Reports, Vol. 3, 1595, 2013.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Electric double-layer capacitance between an ionic liquid and few-layer graphene
AU - Uesugi, Eri
AU - Goto, Hidenori
AU - Eguchi, Ritsuko
AU - Fujiwara, Akihiko
AU - Kubozono, Yoshihiro
PY - 2013
Y1 - 2013
N2 - Ionic-liquid gates have a high carrier density due to their atomically thin electric double layer (EDL) and extremely large geometrical capacitance C g. However, a high carrier density in graphene has not been achieved even with ionic-liquid gates because the EDL capacitance C EDL between the ionic liquid and graphene involves the series connection of C g and the quantum capacitance C q, which is proportional to the density of states. We investigated the variables that determine C EDL at the molecular level by varying the number of graphene layers n and thereby optimising C q. The C EDL value is governed by C q at n <4, and by C g at n > 4. This transition with n indicates a composite nature for C EDL. Our finding clarifies a universal principle that determines capacitance on a microscopic scale, and provides nanotechnological perspectives on charge accumulation and energy storage using an ultimately thin capacitor.
AB - Ionic-liquid gates have a high carrier density due to their atomically thin electric double layer (EDL) and extremely large geometrical capacitance C g. However, a high carrier density in graphene has not been achieved even with ionic-liquid gates because the EDL capacitance C EDL between the ionic liquid and graphene involves the series connection of C g and the quantum capacitance C q, which is proportional to the density of states. We investigated the variables that determine C EDL at the molecular level by varying the number of graphene layers n and thereby optimising C q. The C EDL value is governed by C q at n <4, and by C g at n > 4. This transition with n indicates a composite nature for C EDL. Our finding clarifies a universal principle that determines capacitance on a microscopic scale, and provides nanotechnological perspectives on charge accumulation and energy storage using an ultimately thin capacitor.
UR - http://www.scopus.com/inward/record.url?scp=84876549651&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84876549651&partnerID=8YFLogxK
U2 - 10.1038/srep01595
DO - 10.1038/srep01595
M3 - Article
C2 - 23549208
AN - SCOPUS:84876549651
VL - 3
JO - Scientific Reports
JF - Scientific Reports
SN - 2045-2322
M1 - 1595
ER -