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arXiv · 1510.08262

Negative Compressibility in Graphene-terminated Black Phosphorus Heterostructures

Yingying Wu·Xiaolong Chen·Zefei Wu·Shuigang Xu·Tianyi Han·Jiangxiazi Lin·Yuan Cai·Yuheng He·Chun Cheng·Ning Wang
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Abstract

Negative compressibility generated by many-body effects in 2D electronic systems can enhance gate capacitance. We observe capacitance enhancement in a newly emerged 2D layered material, atomically thin black phosphorus (BP). The encapsulation of BP by hexagonal boron nitride sheets with few-layer graphene as a terminal ensures ultraclean heterostructure interfaces, allowing us to observe negative compressibility at low hole carrier concentrations. We explained the negative compressibility based on the Coulomb correlation among in-plane charges and their image charges in a gate electrode in the framework of Debye screening.

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Yingying Wu, Xiaolong Chen, Zefei Wu, Shuigang Xu, Tianyi Han, Jiangxiazi Lin, Yuan Cai, Yuheng He, Chun Cheng, Ning Wang. 2015-10-28. Negative Compressibility in Graphene-terminated Black Phosphorus Heterostructures. https://doi.org/10.1103/physrevb.93.035455

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