Sreejivungsa Kaniknun, Thanamoon Noppakorn, Phromviyo Nutthakritta, Jarernboon Wirat, Takesada Masaki, Thongbai Prasit
Giant Dielectric and Computational Design Research Group (GD-CDR), Department of Physics, Faculty of Science, Khon Kaen University, Khon Kaen, 40002, Thailand.
Department of Physics, Hokkaido University, Sapporo, 060-0810, Japan.
Sci Rep. 2024 Apr 27;14(1):9726. doi: 10.1038/s41598-024-60421-y.
This research explores the capacitive humidity sensing properties of CuO ceramic, selected for its simplicity as an oxide and ease of fabrication, in addition to its remarkable dielectric properties. The CuO sample was fabricated by sintering at 980 °C for 5 h. A microstructure with a relative density of 88.9% was obtained. X-ray diffraction confirmed the formation of a pure CuO phase. Broadband dielectric spectroscopy revealed that the observed giant dielectric properties at room temperature (RT) were attributed to extrinsic effects, including the internal barrier layer capacitor and sample-electrode contact effects. A key focus of this study was to examine the giant dielectric properties of CuO ceramic as a function of relative humidity (RH) at RT and frequencies of 10 and 10 Hz. It was observed that the capacitance of CuO continuously increased with rising RH levels, ranging from 30 to 95%. Notably, the maximum hysteresis errors were constrained to 2.3 and 3.3% at 10 and 10 Hz, respectively. Additionally, the CuO ceramic demonstrated very fast response and recovery times, approximately 2.8 and 0.95 min, respectively. The repeatability of the humidity response of the capacitance was also established. Overall, this research highlights the high potential of CuO as a giant dielectric material for application in humidity sensors.
本研究探索了CuO陶瓷的电容式湿度传感特性。选择CuO陶瓷是因其作为氧化物结构简单、易于制备，此外还具有卓越的介电性能。CuO样品通过在980℃烧结5小时制备而成。获得了相对密度为88.9%的微观结构。X射线衍射证实形成了纯CuO相。宽带介电谱表明，在室温（RT）下观察到的巨大介电性能归因于外部效应，包括内部势垒层电容器和样品-电极接触效应。本研究的一个关键重点是研究CuO陶瓷在室温及10和10Hz频率下作为相对湿度（RH）函数的巨大介电性能。观察到CuO的电容随着RH水平从30%升至95%而持续增加。值得注意的是，在10和10Hz时，最大滞后误差分别限制在2.3%和3.3%。此外，CuO陶瓷表现出非常快的响应和恢复时间，分别约为2.8和0.95分钟。还确定了电容湿度响应的可重复性。总体而言，本研究突出了CuO作为湿度传感器应用的巨大介电材料的高潜力。
