Multi‐Length Engineering of (K, Na)NbO3 Films for Lead‐Free Piezoelectric Acoustic Sensors with High Sensitivity
Multi‐Length Engineering of (K, Na)NbO3 Films for Lead‐Free Piezoelectric Acoustic Sensors with High Sensitivity
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DOI：
10.1002/adfm.202312699
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发表时间：
2023-12
影响因子：
19
通讯作者：
Yi‐Xuan Liu;Jinling Zhou;Yuqi Jiang;Chen-Bo-Wen Li;Chao Li;Jingwen Lu;Ze Xu;Fang-Zhou Yao;Hu Nan;Dawei Wang;Liqiang Xu;Yicheng Wang;Yijia Du;Jingkai Nie;Zhixiang Zhu;Wen Gong;Bing Han;Ke Wang
中科院分区：
文献类型：
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作者：
Yi‐Xuan Liu;Jinling Zhou;Yuqi Jiang;Chen-Bo-Wen Li;Chao Li;Jingwen Lu;Ze Xu;Fang-Zhou Yao;Hu Nan;Dawei Wang;Liqiang Xu;Yicheng Wang;Yijia Du;Jingkai Nie;Zhixiang Zhu;Wen Gong;Bing Han;Ke Wang
随着人们对噪声污染的日益关注，追求高可靠性的压电声传感器实时监测噪声已经走到了科学研究的前沿。以锆钛酸铅(PZT)为代表的铅基钙钛矿压电薄膜在压电性能上超过了传统的氧化锌和氮化铝等压电材料，有望在下一代声学传感器技术中取得实质性的进步。然而，PZT材料中铅的有毒性质对环境和人类健康构成了巨大的风险。这是一项前所未有的突破，它提出了一种基于Nb酸钾钠(K，Na)NbO_3(KNN)薄膜的环保型无铅压电微机电系统(MEMS)声传感器的开创性开发。高质量织构的3微米厚的KNN薄膜被成功地集成到商业使用的硅衬底中，呈现出出色的压电性(横向压电系数e31*≈8.5Cm−2)，并具有令人满意的热稳定性。原子尺度的Z衬度成像和压电响应力显微镜表征表明，多相的局域共存和面内极化各向异性对非本征压电体贡献的增强是产生显著的压电响应的原因。采用有限元模拟的方法设计了三角形悬臂梁结构和环形膜片结构，分别对应不同的工作带宽。由于KNN薄膜具有良好的压电性，所得到的MEMS声学传感器具有突出的声学性能(高灵敏度和大接收视场)，这归功于多长度尺度的微结构工程。这些功能可以在各种环境中进行灵敏的声学监测，包括大规模电网和城市交通。
With increasing concerns about noise pollution, the pursuit of highly dependable piezoelectric acoustic sensors for real‐time noise monitoring has come to the forefront of scientific research. Lead‐based perovskite piezoelectric films, exemplified by lead zirconate titanate Pb(Zr,Ti)O3 (PZT), surpass traditional piezoelectric materials such as ZnO and AlN in their piezoelectric properties, promising substantial advancements in next‐generation acoustic sensor technologies. However, the toxic nature of lead in PZT materials poses formidable environmental and human health risks. In an unprecedented breakthrough, it presents the pioneering development of an environmentally benign lead‐free piezoelectric Micro‐Electro‐Mechanical System (MEMS) acoustic sensor based on potassium sodium niobate (K,Na)NbO3 (KNN) film. High‐quality textured 3 µm‐thick KNN film is successfully integrated into commercially used Si substrate, rendering exceptional piezoelectricity (transverse piezoelectric coefficients e31* of ≈8.5 C m−2) with satisfactory thermal stability. The atomic‐scale Z‐contrast imaging and piezoresponse force microscopy characterizations reveal that the outstanding piezoresponse originates from the local coexistence of multiple phases and the enhancement of extrinsic piezoelectric contributions from in‐plane polarization anisotropy. Finite element simulation is employed to design the triangular cantilever structure and annular diaphragm structure, each corresponding to different operating bandwidths. The resultant MEMS acoustic sensors stand out with outstanding acoustic performance (the high sensitivity and expansive receiving field of view), which are attributed to the microstructural engineering at multi‐length scales for the excellent piezoelectric properties of KNN film. These features enable sensitive acoustic monitoring in various environments, including large‐scale power grids and urban traffic.