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Voltage Scaling of Graphene Device on SrTiO3 Epitaxial Thin Film
journal contribution
posted on 2016-02-08, 00:00 authored by Jeongmin Park, Haeyong Kang, Kyeong Tae Kang, Yoojoo Yun, Young Hee Lee, Woo Seok Choi, Dongseok SuhElectrical
transport in monolayer graphene on SrTiO3 (STO) thin film
is examined in order to promote gate-voltage scaling using a high-k dielectric material. The atomically flat surface of thin
STO layer epitaxially grown on Nb-doped STO single-crystal substrate
offers good adhesion between the high-k film and
graphene, resulting in nonhysteretic conductance as a function of
gate voltage at all temperatures down to 2 K. The two-terminal conductance
quantization under magnetic fields corresponding to quantum Hall states
survives up to 200 K at a magnetic field of 14 T. In addition, the
substantial shift of charge neutrality point in graphene seems to
correlate with the temperature-dependent dielectric constant of the
STO thin film, and its effective dielectric properties could be deduced
from the universality of quantum phenomena in graphene. Our experimental
data prove that the operating voltage reduction can be successfully
realized due to the underlying high-k STO thin film,
without any noticeable degradation of graphene device performance.