Enhanced sensing performance of relative humidity sensors using laterally grown ZnO nanosheets

This study investigates the effectiveness of using laterally oriented zinc oxide (ZnO) nanosheets (NSs) grown by the hydrothermal growth (HTG) method for relative humidity (RH) sensing at room temperature (RT). A sensing response (R12%/R96%) at RT of as high as 220, good sensing linearity in the range of 12–96% RH, a fast sensing response time of as low as 600 s, and a recovery time of 3 s are achieved. Compared to conventional ZnO-nanowire-based humidity sensors, a 100-fold improvement in the sensing response at RT was obtained, which is mainly attributed to the ZnO NSs having a much higher surface-to-volume ratio and a porous-like surface.