BST/Si-NPA复合薄膜的湿敏电容特性研究

本文采用溶胶-凝胶法和旋涂工艺，以Si-NPA为衬底，制备了钛酸锶钡(BST)/Si-NPA复合薄膜，并对其形貌、结构及湿敏电容特性进行了研究。结果表明，环境的相对湿度(RH)、测试信号频率和退火温度均对湿敏电容特性具有较大影响。在100 Hz的测试信号频率下，当环境的相对湿度从11%上升到95%时，BST/Si-NPA湿敏元件的电容增量可达起始值的4 400%，显示出较高的湿度敏感性。同时，元件的响应时间和恢复时间均约为42 s，表现出较快的时间响应和均衡的吸附/脱附。最后，通过复阻抗法讨论了元件的感湿机理。

Capacitive Humidity Sensing Properties of BST/Si-NPA Composite Thin Films

BST/Si-NPA composite thin films were fabricated based on Si-NPA substrate using sol-gel method and spin-coating technology. The morphology,microstructure and capacitive humidity sensing properties were investigated. Experimental results show that the capacitance strongly depends on relative humidity (RH),measured frequency and annealing temperature. The capacitance increment was over 4 400% of its initial value when RH was increased from 11% to 95% at 100 Hz signal frequency,indicating high humidity sensitivity. At the same time,the response times both for RH-increasing process and RH-decreasing process were determined to be ~42 s,respectively,showing rapid time response as well as time proportion in adsorption and desorption. In the end,the humidity sensing mechanism of BST/Si-NPA humidity sensors is discussed by double impedance method.