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arXiv · 1111.0411

Single-layer behavior and slow carrier density dynamic of twisted graphene bilayer

Lan Meng·Yanfeng Zhang·Wei Yan·Lei Feng·Lin He·Rui-Fen Dou·Jia-Cai Nie
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Abstract

We report scanning tunneling microscopy (STM) and spectroscopy (STS) of twisted graphene bilayer on SiC substrate. For twist angle ~ 4.5o the Dirac point ED is located about 0.40 eV below the Fermi level EF due to the electron doping at the graphene/SiC interface. We observed an unexpected result that the local Dirac point around a nanoscaled defect shifts towards the Fermi energy during the STS measurements (with a time scale about 100 seconds). This behavior was attributed to the decoupling between the twisted graphene and the substrate during the measurements, which lowers the carrier density of graphene simultaneously.

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Lan Meng, Yanfeng Zhang, Wei Yan, Lei Feng, Lin He, Rui-Fen Dou, Jia-Cai Nie. 2011-11-02. Single-layer behavior and slow carrier density dynamic of twisted graphene bilayer. https://doi.org/10.1063/1.3691952

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