A vacuum pressure sensor based on ZnO nanobelt film

Abstract

A vacuum pressure sensor was fabricated by assembling ZnO nanobelt film on theinterdigital electrodes, and the current–voltage characteristics were measuredwith an Agilent semiconductor parameter tester. Under different pressures of1.0 × 103,6.7 × 10 − 3,8.2 × 10 − 4 and9.5 × 10 − 5 mbar, thecurrents are 8.71, 28.1, 46.1 and 89.6 nA, and the pressure sensitive resistances are 1150, 356, 217 and 112 MΩ, respectively. Inthe range of 10 − 5–103 mbar the smaller the pressure is, the higher the current is. The pressure sensitiveresistance of the vacuum pressure sensor increases linearly with the logarithmicpressure, and the measurement range is at least one order of magnitude widerthan that of the previous sensors. Under the final pressure, the vacuumpressure sensor has maximum sensitivity (9.29) and power consumption of 0.9 µW. The sensitivity is larger than that of the previous sensor based on a ZnO singlenanowire at that pressure, and the power consumption is much lower than that forthe sensor based on a ZnO nanowire array. The pressure sensitive mechanism isreasonably explained by using oxygen chemisorption and energy band theory.