Pure In2O3 NBs and Er-In2O3 NBs have been successfully synthesized by carbon thermal reduction. The doping of Er leads the optimal temperature of the In2O3 to decrease. The response of the Er-In2O3 sensor to 100 ppm of alcohol is 4.8 at 220 degrees C, which is twice larger than that of the pure In2O3 sensor. It is also found that the doping of Er has increased the performance of the sensors. Moreover, Er-In2O3 sensor has a fast response (recovery) time to different concentration of alcohol at 220 degrees C. In addition, the mechanism of pure In2O3 sensor and Er-In2O3 sensor are discussed. (C) 2016 Elsevier B.V. All rights reserved.