Ma Hailong, Fang Huajing, Wu Wenting, Zheng Cheng, Wu Liangliang, Wang Hong
State Key Laboratory for Mechanical Behavior of Materials, School of Material Science and Engineering, Xi'an Jiaotong University Xi'an 710049 China
School of Electronic and Information Engineering, State Key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University Xi'an 710049 China.
RSC Adv. 2020 Jul 6;10(43):25467-25474. doi: 10.1039/d0ra03958f. eCollection 2020 Jul 3.
Metal oxide based humidity sensors are important indicators in environmental monitoring. However, most of them are non-transparent and have a long response time, which cannot meet the application of real-time humidity sensing in transparent electronics. Here, we report a metal oxide humidity sensor based on chemically synthesized molybdenum oxide (α-MoO) thin films. By a green reaction in an ice water bath, the stable precursor containing nanocrystalline colloids was obtained. Molybdenum oxide films with controllable morphology were fabricated through one-step spin coating. The α-MoO based humidity sensor exhibits extremely high transparency (85%) in the visible region and has short response and recovery times (0.97 and 12.11 s). In addition, it also shows high sensitivity, good logarithmic linearity and selectivity in a wide relative humidity range of 11% to 95%. The mechanism of humidity sensing was further studied by complex impedance spectroscopy. This novel metal oxide humidity sensor combined with high transparency and fast response speed is expected to broaden the application ranges of humidity sensors.
基于金属氧化物的湿度传感器是环境监测中的重要指标。然而，它们大多不透明且响应时间长，无法满足透明电子器件中实时湿度传感的应用需求。在此，我们报道了一种基于化学合成氧化钼（α-MoO）薄膜的金属氧化物湿度传感器。通过在冰水浴中的绿色反应，获得了含有纳米晶胶体的稳定前驱体。通过一步旋涂制备了形貌可控的氧化钼薄膜。基于α-MoO的湿度传感器在可见光区域具有极高的透明度（85%），且响应和恢复时间短（分别为0.97秒和12.11秒）。此外，在11%至95%的宽相对湿度范围内，它还表现出高灵敏度、良好的对数线性和选择性。通过复阻抗谱进一步研究了湿度传感机制。这种结合了高透明度和快速响应速度的新型金属氧化物湿度传感器有望拓宽湿度传感器的应用范围。
