Zhang Zheng, Liao Qingliang, Zhang Xiaohui, Zhang Guangjie, Li Peifeng, Lu Shengnan, Liu Shuo, Zhang Yue
State Key Laboratory for Advanced Metals and Materials, School of Materials Science and Engineering, University of Science and Technology Beijing, China.
Nanoscale. 2015 Feb 7;7(5):1796-801. doi: 10.1039/c4nr05597g.
Piezotronic strain sensors have drawn a lot of attention since the piezotronic theory was established. In this work, we developed a flexible piezotronic strain sensor based on an indium-doped ZnO nanobelt, of which the top surface was the monopolar surface. By connecting two electrodes with the two ends of the top surface of the nanobelt, the strain sensor was constructed. Compared with a nanorod/nanowire based strain sensor, this monopolar surface device avoids the need to identify the polar direction. Under strain, a static potential with the same value and polarity was generated by the coupling effect of the piezoelectric effect and the Poisson effect. This induced piezopotential influenced the Schottky barrier heights at the interfaces of both the source and drain electrodes, resulting in current changes with the same trend at forward and reverse biases. By applying a series of periodical strains, the sensor showed clear, fast and accurate current responses. The gauge factor achieved for compressive strain was 4036. This type of piezotronic strain sensor with a polar surface facing upward presented a high performance and easier fabrication, showing promise for applications in electrical mechanical sensors and MEMS.
自从压电子理论建立以来，压电子应变传感器就备受关注。在这项工作中，我们基于铟掺杂的氧化锌纳米带开发了一种柔性压电子应变传感器，其顶面为单极表面。通过将两个电极与纳米带顶面的两端相连，构建了应变传感器。与基于纳米棒/纳米线的应变传感器相比，这种单极表面器件无需确定极性方向。在应变作用下，压电效应和泊松效应的耦合作用产生了具有相同值和极性的静态电势。这种感应压电势影响了源极和漏极电极界面处的肖特基势垒高度，导致在正向和反向偏置下电流变化趋势相同。通过施加一系列周期性应变，该传感器显示出清晰、快速且准确的电流响应。压缩应变下的应变系数达到了4036。这种顶面朝上的极性表面的压电子应变传感器具有高性能且易于制造，在机电传感器和微机电系统中显示出应用前景。
