High Performance SnO₂/MoS₂-Based Surface Acoustic Wave Humidity Sensor With Good Linearity

Abstract

In this work, we developed a high-performance SAW humidity sensor based on SnO ₂ /MoS ₂ nanocomposite as the sensitive layer while PMN-PT as the piezoelectric layer. The SAW device was fabricated via thinning bulk PMN-PT and standard photolithography and ion beam etching process. After that, the humidity sensor was assembled by drop-casting hydrothermal synthetic SnO ₂ /MoS ₂ composite on the SAW device. The exploit of sensing layer SnO ₂ /MoS ₂ result in the high performance of the sensor because of its excellent humidity sensing behavior. Therefore, this humidity sensor exhibited both an excellent linearity of R ² > 0.98 in all detecting range (10-90%RH) and high sensitivity of 0.78 kHz/%RH and 8.87 ppm/%RH. Meanwhile, low hysteresis characteristic, good repeatability and long-term stability were also achieved, indicating that this developed sensor is a favourable candidate for humidity detection.