Enhanced piezo-humidity sensing of Sb-doped ZnO nanowire arrays as self-powered/active humidity sensor

•New portable room-temperature humidity sensor is realized, and no external electric power is needed.•Sb-doped ZnO nanowire arrays are synthesized via a very facile way.•The device has high sensitivity against humidity.•New piezo-sensing mechanism with element doping for humidity detecting is established.

Room-temperature self-powered/active humidity sensing has been realized from Sb-doped ZnO nanowire (NW) arrays by coupling their piezoelectric and gas sensing characteristics. The piezoelectric output of the device acts as both the power source and the response signal against relative humidity (RH). Upon exposure to 70% RH, the piezoelectric output of Sb-doped ZnO NWs decreases from 1.35 V (10% RH) to 0.22 V, and the response is 83.70 (much higher than that of undoped ZnO).