High-Sensitivity Humidity Sensor Based on a Single Sb-Doped SnO2 Whisker

Sb-doped SnO2 whiskers were prepared by thermal evaporation of mixture of SnO and Sb2O3 powders Sb segregation to the surface of SnO2 whisker was demonstrated The humidity sensitive characteristics of single SnO2 whisker-based sensors have been investigated By monitoring the current through the SnO2 whisker at fixed voltage, relative humidity can be determined It is found that the current of the Sb-doped SnO2 whisker-based sensor increases by about five orders of magnitude with increasing relative humidity (RH) from 43.2 to 84 3% The response and recovery time of the sensor are approximate 12 and 8 s, respectively Compared to the pure SnO2 whisker, Sb-doped SnO2 whisker exhibits greatly improvement of sensitivity which could be explained by the surface-segregated Sb atoms This is the first step towards fundamental understanding of single-crystalline tin oxide whiskers for sensor applications, which could lead to integration in real devices.