A vacuum pressure sensor based on ZnO nanobelt film.

A vacuum pressure sensor was fabricated by assembling ZnO nanobelt film on the interdigital electrodes, and the current–voltage characteristics were measured with an Agilent semiconductor parameter tester. Under different pressures of 1.0 × 10(3), 6.7 × 10(−3), 8.2 × 10(−4) and 9.5 × 10(−5) mbar, the currents are 8.71, 28.1, 46.1 and 89.6 nA, and the pressure sensitive resistances are 1150, 356, 217 and 112 MΩ, respectively. In the range of 10(−5)–10(3) mbar the smaller the pressure is, the higher the current is. The pressure sensitive resistance of the vacuum pressure sensor increases linearly with the logarithmic pressure, and the measurement range is at least one order of magnitude wider than that of the previous sensors. Under the final pressure, the vacuum pressure 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 single nanowire at that pressure, and the power consumption is much lower than that for the sensor based on a ZnO nanowire array. The pressure sensitive mechanism is reasonably explained by using oxygen chemisorption and energy band theory.