表面SiO_2改性高选择性MOS氢气传感器

Highly Selective MOS Hydrogen Gas Sensor Using the SiO_2 Modified Layers

以十甲基环五硅氧烷(D5)为硅源,采用化学气相沉积法(CVD)在SnO_2气体传感器表面沉积SiO_2膜作为改性层,研究了CVD处理过程中温度和处理时间对传感器的选择性和灵敏性影响。通过对乙醇、丙酮、苯和氢气的气敏性能测试,得出在500℃下CVD处理8 h后的SnO_2传感器对氢气具有最好的选择性和灵敏性。同时讨论了Si O2改性层提高SnO_2传感器选择性和灵敏性的机理。

The surface modification of ordinary SnO 2 sensors were prepared by chemical vapor deposition（CVD）method,and the SiO 2 film was deposited on the SnO 2 sensor surface as the modified layers which came from the high temperature decomposition of decamethylcyclopentasiloxane（D5）. The effects of the different temperature and processing time of the CVD process on the hydrogen selectivity and sensitivity of the gas sensors were studied by measuring ethanol,acetone,benzene and hydrogen. It can be concluded that the SnO 2 sensor,processed by CVD method at 500 ℃ for 8 hours,has the best selectivity and sensitivity to hydrogen. The mechanism of the selectivity and sensitivity improvement of the gas sensors to hydrogen was also discussed.