Capacitive humidity-sensing properties of Zn2SiO4 film grown on silicon nanoporous pillar array

A Zn2SiO4 thin film was grown on silicon nanoporous pillar array (Si-NPA) via a chemical vapor deposition method, and the capacitive humidity-sensing properties of Zn2SiO4/Si-NPA were investigated at room temperature. With the relative humidity (RH) changing from 11% to 95%, the capacitance of the sensor increased from 1.67 to 135.97 nF at the testing frequency of 20 Hz, and an overall increment of 8042% was obtained. The response and recovery time was measured to be 48 and 32 s, respectively. The sensor showed a maximum humidity hysteresis of 1.99% at 75% RH. These results indicated that Zn2SiO4/Si-NPA might be a promising material for fabricating high-performance capacitive humidity sensors.