纳米尖端场离子化气体传感器的动态测试方法研究

Study on the Dynamic Measurement of Nanotips Field Ionization Gas Sensor

制作了一种纳米尖端场离子化气体传感器,以氧化锌纳米尖端为阳极,钨针为阴极,采用皮安表向传感器提供输出波形可控的直流电源,测量流过器件的预击穿电流。由于采用了纳米尖端进行离子化,有效地降低了传感器的击穿电压,提高了传感器的离子化能力,而且避免了氧化锌材料以空气作为背景测试气体时的氧化问题。动态测试预击穿电流的方法提高了器件的实用性。实验结果显示该传感器对乙酸蒸气有较好的响应,而且可以做定量测量。所制场离子化气体传感器适于普通空气条件下的使用,具有良好的应用前景。

A field ionization gas sensor with ZnO nanotips was fabricated. The ZnO nanotips served as anode and the tungsten needle as cathode were separated and insulated by a glass insulator. The waveform controlled dc was applied to the sensor and the prebreakdown current flowing through the sensor was measured by the picoammeter. By using the nanotips field ionization technique, the breakdown voltage of the sensor was lowered and the ionizing ability was improved. In addition, the practicability of the field ionization gas sensor was further improved by using the dynamic measurement proposed in this paper. Experimental result showed that the field ionization sensor was sensitive to acetic acid gas, but not to acetone gas and could be quantitatively measured. This kind of nanotips field ionization gas sensor can be used appropriately in normal air.