Chau Tuan Khanh, Suh Dongseok, Kang Haeyong
Department of Energy Science, Sungkyunkwan University, Suwon 16419, Korea.
Department of Physics, Pusan National University, Busan 46241, Korea.
Materials (Basel). 2021 Dec 21;15(1):8. doi: 10.3390/ma15010008.
Charge carrier scattering at grain boundaries (GBs) in a chemical vapor deposition (CVD) graphene reduces the carrier mobility and degrades the performance of the graphene device, which is expected to affect the quantum Hall effect (QHE). This study investigated the influence of individual GBs on the QH state at different stitching angles of the GB in a monolayer CVD graphene. The measured voltage probes of the equipotential line in the QH state showed that the longitudinal resistance () was affected by the scattering of the GB only in the low carrier concentration region, and the standard QHE of a monolayer graphene was observed regardless of the stitching angle of the GB. In addition, a controlled device with an added metal bar placed in the middle of the Hall bar configuration was introduced. Despite the fact that the equipotential lines in the controlled device were broken by the additional metal bar, only the was affected by nonzero resistance, whereas the Hall resistance () revealed the well-quantized plateaus in the QH state. Thus, our study clarifies the effect of individual GBs on the QH states of graphenes.
化学气相沉积（CVD）石墨烯中晶界（GBs）处的载流子散射会降低载流子迁移率并降低石墨烯器件的性能，预计这会影响量子霍尔效应（QHE）。本研究调查了单层CVD石墨烯中单个晶界在不同拼接角度下对量子霍尔态的影响。在量子霍尔态下对等势线的测量电压探针显示，纵向电阻（）仅在低载流子浓度区域受晶界散射的影响，并且无论晶界的拼接角度如何，都观察到了单层石墨烯的标准量子霍尔效应。此外，还引入了一种在霍尔条形结构中间放置附加金属条的受控器件。尽管受控器件中的等势线被附加金属条破坏，但只有受到非零电阻的影响，而霍尔电阻（）在量子霍尔态中显示出良好的量子化平台。因此，我们的研究阐明了单个晶界对石墨烯量子霍尔态的影响。
