Realization of a Flexible Humidity Sensor Based on α‐In₂Se₃ Nanosheets

Abstract Humidity sensors are widely used in domestic and industrial environments. The humidity sensing requires a sensor to be both flexible and stable. However, challenges still exist for the realization of efficient flexible humidity sensors. Herein, α‐In₂Se₃ nanosheet‐based humidity sensors both on PET and SiO₂/Si substrates are fabricated. The humidity sensing behaviors are investigated in a wide relative humidity (RH) range from 11% RH to 97% RH at room temperature. Compared with a silicon‐based humidity sensor based on α‐In₂Se₃ nanosheets, the flexible humidity sensor based on α‐In₂Se₃ nanosheet exhibits higher sensitivity of 2.38×10³%, shorter response and recovery time of 9 s and 13 s. Due to the lower activation energy of the flexible humidity sensor, the sensitivity of the flexible humidity sensor being 25 times higher than that of the silicon‐based humidity sensor. These results indicate that α‐In₂Se₃ nanosheet may be a potential humidity‐sensing material for fabricating humidity sensors with high performance, and the flexible humidity sensor based on α‐In₂Se₃ nanosheet has great potential in flexible wearable electronic devices.