Gogneau Noelle, Chrétien Pascal, Sodhi Tanbir, Couraud Laurent, Leroy Laetitia, Travers Laurent, Harmand Jean-Chistophe, Julien François H, Tchernycheva Maria, Houzé Frédéric
Centre de Nanosciences et Nanotechnologies, Université Paris-Saclay, CNRS, UMR9001, Boulevard Thomas Gobert, 91120 Palaiseau, France.
Université Paris-Saclay, CentraleSupélec, Sorbonne Université, CNRS, Laboratoire de Génie électrique et électronique de Paris, 11 rue Joliot-Curie, 91190 Gif sur Yvette, France.
Nanoscale. 2022 Mar 31;14(13):4965-4976. doi: 10.1039/d1nr07863a.
The piezoelectric nanowires (NWs) are considered as promising nanomaterials to develop high-efficient piezoelectric generators. Establishing the relationship between their characteristics and their piezoelectric conversion properties is now essential to further improve the devices. However, due to their nanoscale dimensions, the NWs are characterized by new properties that are challenging to investigate. Here, we use an advanced nano-characterization tool derived from AFM to quantify the piezo-conversion properties of NWs axially compressed with a well-controlled applied force. This unique technique allows to establish the direct relation between the output signal generation and the NW stiffness and to quantify the electromechanical coupling coefficient of GaN NWs, which can reach up to 43.4%. We highlight that this coefficient is affected by the formation of the Schottky nano-contact harvesting the piezo-generated energy, and is extremely sensitive to the surface charge effects, strongly pronounced in sub-100 nm wide GaN NWs. These results constitute a new building block in the improvement of NW-based nanogenerator devices.
压电纳米线（NWs）被认为是开发高效压电发电机的有前途的纳米材料。建立它们的特性与其压电转换特性之间的关系对于进一步改进器件至关重要。然而，由于其纳米尺度尺寸，NWs具有一些难以研究的新特性。在此，我们使用一种源自原子力显微镜（AFM）的先进纳米表征工具，以量化在精确控制的外力作用下轴向压缩的NWs的压电转换特性。这种独特的技术能够建立输出信号产生与NW刚度之间的直接关系，并量化GaN NWs的机电耦合系数，该系数可达43.4%。我们强调，该系数受用于收集压电产生能量的肖特基纳米接触形成的影响，并且对表面电荷效应极其敏感，在宽度小于100 nm的GaN NWs中表现得尤为明显。这些结果构成了改进基于NW的纳米发电机器件的一个新基石。
