Kholkin Andrei L, Ushakov Andrei D, Chuvakova Maria A, Kosobokov Mikhail S, Akhmatkhanov Andrey R, Turutin Andrei V, Chichkov Maxim V, Kravchenko Ivan I, Kopelevich Yakov, Shur Vladimir Ya
IEEE Trans Ultrason Ferroelectr Freq Control. 2020 Oct;67(10):2142-2147. doi: 10.1109/TUFFC.2020.2998976. Epub 2020 Jun 3.
Ferroelectric materials based on lead zirconate titanate (PZT) are widely used as sensors and actuators because of their strong piezoelectric activity. However, their application is limited because of the high processing temperature, brittleness, lack of conformal deposition, and a limited possibility to be integrated with the microelectromechanical systems (MEMS). Recent studies on the piezoelectricity in the 2-D materials have demonstrated their potential in these applications, essentially due to their flexibility and integrability with the MEMS. In this work, we deposited a few layer graphene (FLG) on the amorphous oxidized SiN membranes and studied their piezoelectric response by sensitive laser interferometry and rigorous finite-element modeling (FEM) analysis. Modal analysis by FEM and comparison with the experimental results show that the driving force for the piezoelectric-like response can be a polar interface layer formed between the residual oxygen in SiN and the FLG. The response was about 14 nm/V at resonance and could be further enhanced by adjusting the geometry of the device. These phenomena are fully consistent with the earlier piezoresponse force microscopy (PFM) observations of the piezoelectricity of the graphene on SiO and open up an avenue for using graphene-coated structures in the MEMS.
基于锆钛酸铅（PZT）的铁电材料因其强大的压电活性而被广泛用作传感器和致动器。然而，由于其加工温度高、脆性大、缺乏保形沉积以及与微机电系统（MEMS）集成的可能性有限，其应用受到限制。最近关于二维材料中压电性的研究表明了它们在这些应用中的潜力，这主要归因于它们的灵活性以及与MEMS的可集成性。在这项工作中，我们在非晶氧化氮化硅膜上沉积了几层石墨烯（FLG），并通过灵敏的激光干涉测量法和严格的有限元建模（FEM）分析研究了它们的压电响应。有限元模态分析以及与实验结果的比较表明，类似压电响应的驱动力可能是氮化硅中的残余氧与FLG之间形成的极性界面层。在共振时，响应约为14纳米/伏，并且可以通过调整器件的几何形状进一步增强。这些现象与早期关于石墨烯在SiO上的压电性的压电力显微镜（PFM）观察结果完全一致，并为在MEMS中使用石墨烯涂层结构开辟了一条途径。
