基于超长ZnO纳米线阵列的压电型次声传感器研究

Infrasonic transducers are widely utilized for monitoring earthquake, tsunami, nuclear explosion, environment noise, and so on. But most of the infrasonic transducers have a few disadvantages, such as low sensitivity, temperature drift instability, low compatibility and large volume. Considering the problems with the infrasonic transducer, we present here a novel piezoelectric infrasonic transducer based on ultra-long ZnO nanowire arrays, aiming for micromation, high sensitivity, wide response frequency and high stability. The outstanding performance of ZnO nanowire, such as large slenderness ratio, single crystal, high piezoelectricity, good flexibility and controllable synthesis, is applied to fabricating piezoelectric transducer. The piezoelectric potential created between two ends of ZnO nanowire when tensile strain is used as response signal, and the signal is enhanced by integrating huge nanowires. In our advanced project, we pay attention to some key technical matters, controllable synthesis of ultra-long ZnO nanowire arrays, transferring ZnO nanowire arrays dry contact printing method, neutralization oxygen vacancies of nanowires by oxygen plasma treatment, fabricating and testing the infrasonic transducer. In brief, we present a technical plan to achieve a high performance piezoelectric infrasonic transducer based on ultra-long ZnO nanowire arrays. Our researches to be carried out will greatly promote the application prospect of the transducer in geophysics, environmental monitoring and military field.

目前次声传感器已广泛应用在地震、海啸次声波检测，核爆炸次声波检测，环境次声污染监控等领域，而现有技术中的传感器大部分存在灵敏度低、温度漂移大、一致性差、体积较大等缺陷。本项目以微型化、灵敏度高、频率响应宽、工作稳定性好的次声传感器为研究目标，提出基于超长ZnO纳米线阵列的压电型次声传感器研究。利用ZnO纳米线高长径比、单晶结构、压电性能高、柔韧性好、可实现可控生长等优点，以纳米线响应振动时的径向压电输出作为响应信号，研制高灵敏的微型化次声传感器，并通过大量纳米线的并联提高压电信号的输出。重点解决超长ZnO纳米线阵列的可控生长技术，ZnO纳米线阵列的接触印刷转移技术，抑制纳米线表面氧空位的氧离子表面处理技术，以及器件的制作和测试等关键科学问题。通过本项目的研究，为实现微型化、高灵敏度的压电型次声传感器奠定基础，并为其在地球物理、环境监测和军事领域开辟广阔的应用前景。

目前次声传感器已广泛应用在地震、海啸次声波检测，核爆炸次声波检测，环境次声污染监控等领域，而现有技术中的传感器大部分存在灵敏度低、温度漂移大、一致性差、体积较大等不足，有待进一步的改进。本项目以微型化、灵敏度高、频率响应宽、工作稳定性好的次声传感器为研究目标，提出基于超长ZnO纳米线阵列的压电型次声传感器研究。利用ZnO纳米线高长径比、单晶结构、压电性能高、柔韧性好、可实现可控生长等优点，以纳米线响应振动时的径向压电输出作为响应信号，研制高灵敏的微型化次声传感器，并通过大量纳米线的并联提高压电信号的输出。. 项目重点解决超长ZnO纳米线阵列的可控生长技术，ZnO纳米线阵列的接触印刷转移技术，抑制纳米线表面氧空位的等离子表面处理技术，以及压电器件的制作和测试等关键科学问题。项目采用改进后的CVD方法在ZnO晶种修饰的硅沉底上生长出直径约400nm，长径比达1000的纳米线阵列；并通过接触印刷转移的方法将纳米线到聚酰亚胺柔性沉底上并且保持了纳米线的完整和平行排列；在光刻沉积金属电极的过程中解决了双层光刻胶制作厚电极的技术难题；采用等离子轰击的方式清除纳米线表面吸附物和部分氧空位，提高纳米线与金属电极的接触性能；从理论上分析了金属电极和半导体纳米线的接触势垒对压电电流输出的影响，很好地解释了压电器件内部工作机制与信号输出的关系；对制作的压电次声传感器进行了初步的测试，采用外界的轻微扰动模拟次声的作用，传感器能够实时输出相应的电流信号，电流信号强度在nA量级。该压电器件性能的准确测试以及响应能力的提升有待进一步的研究。. 通过本项目的研究，探索了基于超长ZnO纳米线阵列的压电型次声传感器的关键技术和可行性，为实现微型化、高灵敏度的压电型次声传感器提供了理论和实验基础，并为其在地球物理、环境监测和军事领域开辟广阔的应用前景。