Speaker
E.J. Choi
(Univ. of Seoul, Korea)
Description
Joo Youn Kim (University of Seoul, Seoul 130-743, Republic of Korea)
Kwangnam Yu (University of Seoul, Seoul 130-743, Republic of Korea)
Chul Lee (University of Seoul, Seoul 130-743, Republic of Korea)
Sukang Bae (Sungkyunkwan University, Suwon 440-746, Republic of Korea)
Sang Jin Kim (Sungkyunkwan University, Suwon 440-746, Republic of Korea)
Keun Soo Kim (Sejong University, Graphene Research Institute, Seoul 143-747, Republic of Korea)
Byung Hee Hong (Seoul National University, Seoul 151-742, Republic of Korea)
E. J. Choi (University of Seoul, Seoul 130-743, Republic of Korea)
We determined carrier scattering rate (Γ) of grapheme from Far-IR transmission measurement on CVD-graphene/SiO2/p-Si field effect device. As carrier density (n) is varied by applying the gate voltage exhibits distinct n-dependent change which is represented by two polynomial scatterings as Γ(n) = A/n + B∙√n. The A/n-scattering and B∙√n-scattering plays dominant role in the low-n and high-n regime respectively, whereas they have equal strength at n = nc = 2×10^12 cm-2 . We calculated dc-conductivity (σ0(n)) from Γ(n) finding that σ0(n) exhibits the linear-to-sublinear crossover at n = nc due to that Γ(n) switches from A/n to B∙√n at this density. It accounts for the sub-linear behavior of I-V curve, long-standing puzzle in graphene physics. We discuss possible origin of the A/n and B∙√n scattering in terms of the charged-impurity, phonon, and short-range adatom scattering.
Primary author
E.J. Choi
(Univ. of Seoul, Korea)
