Realization of a Flexible Humidity Sensor Based on alpha-In2Se3 Nanosheets

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, alpha-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 alpha-In2Se3 nanosheets, the flexible humidity sensor based on alpha-In2Se3 nanosheet exhibits higher sensitivity of 2.38x10(3)%, shorter response and recovery time of 9s 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 alpha-In2Se3 nanosheet may be a potential humidity-sensing material for fabricating humidity sensors with high performance, and the flexible humidity sensor based on alpha-In2Se3 nanosheet has great potential in flexible wearable electronic devices.