电荷对磷烯力学行为的影响

来自武汉大学力学系的刘泽教授、高恩来副研究员与中国科学院半导体研究所的邓惠雄研究员合作研究发现，具有高度各项异性结构的磷烯表现出优异的电致驱动性能。向磷烯注入电荷后，其最大驱动应力达7.0 GPa，相应的最大驱动应变高达36.6%，这一致动应变与生物肌肉（20-40%）相当，超过石墨烯（4.7%）7倍。同时，磷烯的最大体积功密度（207.7 J/cm3）比天然肌肉（0.008-0.04 J/cm3）高出三个数量级，比石墨烯（35.3J/cm3）大近6倍。原子和电子结构分析揭示了磷烯具有这种优异电致驱动性能的内在机制。最后，通过力学测试探究了注入的电荷对磷烯力学行为的影响，结果表明在一定的力-电荷载共同作用下磷烯的结构仍保持结构完整。本工作为发展高性能纳米电致驱动器提供了理论参考。

该文近期发表于npj Computational Materials 6： 27 （2020），英文标题与摘要如下，点击左下角“阅读原文”可以自由获取论文PDF。

High-performance phosphorene electromechanical actuators

Bozhao Wu， Hui-Xiong Deng， Xiangzheng Jia， Langquan Shui， Enlai Gao* & Ze Liu*

Phosphorene， a two-dimensional material that can be exfoliated from black phosphorus， exhibits remarkable mechanical， thermal， electronic， and optical properties. In this work， we demonstrate that the unique structure of pristine phosphorene endows this material with exceptional quantum-mechanical performance by using first-principles calculations. Upon charge injection， the maximum actuation stress is 7.0 GPa， corresponding to the maximum actuation strain as high as 36.6% that is over seven times larger than that of graphene （4.7%） and comparable with natural muscle （20-40%）。 Meanwhile， the maximum volumetric work density of phosphorene （207.7 J/cm3） is about three orders of magnitude larger than natural muscle （0.008–0.04 J/cm3） and approximately six times larger than graphene （35.3 J/cm3）。 The underlying mechanism of this exceptional electromechanical performance in phosphorene is well revealed from the analysis of atomic structure and electronic structure. Finally， the influence of charge on the mechanical behaviors of phosphorene is examined by mechanical tests， indicating the sufficient structural integrity of phosphorene under the combined electromechanical loading. These findings shed light on phosphorene for promising applications in developing nanoelectromechanical actuators.

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