Zhun Yong Ong

Atomic-scale evidence for potential barriers and strong carrier scattering at graphene grain boundaries: a scanning tunneling microscopy study.

We use scanning tunneling microscopy and spectroscopy to examine the electronic nature of grain boundaries (GBs) in polycrystalline graphene grown by chemical vapor deposition (CVD) on Cu foil and transferred to SiO(2) substrates. We find no preferential orientation angle between grains, and the GBs are continuous across graphene wrinkles and SiO(2) topography. Scanning tunneling spectroscopy shows enhanced empty states tunneling conductance for most of the GBs and a shift toward more n-type behavior compared to the bulk of the graphene. We also observe standing wave patterns adjacent to GBs propagating in a zigzag direction with a decay length of ~1 nm. Fourier analysis of these patterns indicates that backscattering and intervalley scattering are the dominant mechanisms responsible for the mobility reduction in the presence of GBs in CVD-grown graphene.

Mobility enhancement and temperature dependence in top-gated single-layer MoS2

The deposition of a high-

Topography and refractometry of nanostructures using spatial light interference microscopy

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Pseudopotential-based studies of electron transport in graphene and graphene nanoribbons

oxide overlayer is known to significantly enhance the room-temperature electron mobility in single-layer MoS

Theory of interfacial plasmon-phonon scattering in supported graphene

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Theoretical analysis of high-field transport in graphene on a substrate

(SLM) but not in single-layer graphene. We give a quantitative account of how this mobility enhancement is due to the nondegeneracy of the two-dimensional electron gas system in SLM at accessible temperatures. Using our charged impurity scattering model [Ong and Fischetti, Phys. Rev. B 86, 121409 (2012)] and temperature-dependent polarizability, we calculate the charged impurity-limited mobility (

Charged impurity scattering in top-gated graphene nanostructures

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Top oxide thickness dependence of remote phonon and charged impurity scattering in top-gated graphene

) in SLM with and without a high-

Atomic-scale study of scattering and electronic properties of CVD graphene grain boundaries

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Effect of interfacial phonon-plasmon modes on electrical transport in supported graphene

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