Wang Bingjie, Li Juyao, Fang Zheng, Jiang Yifan, Li Shuo, Zhan Fangyuan, Dai Zhaohe, Chen Qing, Wei Xianlong
Key Laboratory for the Physics and Chemistry of Nanodevices, School of Electronics, Peking University, Beijing 100871, China.
Department of Mechanics and Engineering Science, College of Engineering, Peking University, Beijing 100871, China.
Nano Lett. 2024 Mar 25. doi: 10.1021/acs.nanolett.4c00687.
The axis piezoresistivity is a fundamental and important parameter of graphite, but its value near zero pressure has not been well determined. Herein, a new method for studying the axis piezoresistivity of van der Waals materials near zero pressure is developed on the basis of scanning electron microscopy and finite element simulation. The axis piezoresistivity of microscale highly oriented pyrolytic graphite (HOPG) is found to show a large value of 5.68 × 10 kPa near zero pressure and decreases by 2 orders of magnitude to the established value of ∼10 kPa when the pressure increases to 200 MPa. By modulating the serial tunneling barrier model on the basis of the stacking faults, we describe the axis electrical transport of HOPG under compression. The large axis piezoresistivity near zero pressure and its large decrease in magnitude with pressure are attributed to the rapid stiffening of the electromechanical properties under compression.
轴向压阻率是石墨的一个基本且重要的参数，但其在零压力附近的值尚未得到很好的确定。在此，基于扫描电子显微镜和有限元模拟，开发了一种研究范德华材料在零压力附近轴向压阻率的新方法。发现微尺度高定向热解石墨（HOPG）的轴向压阻率在零压力附近显示出5.68×10 kPa的较大值，当压力增加到200 MPa时，下降2个数量级至约10 kPa的既定值。通过基于堆垛层错调制串联隧穿势垒模型，我们描述了HOPG在压缩下的轴向电输运。零压力附近的大轴向压阻率及其随压力的大幅下降归因于压缩下机电性能的快速增强。
