Sensing properties and mechanism of SnO2 room temperature gas sensors on nanostructured surfaces.

摘要

A novel SnO2 based carbon monoxide gas sensor that can work at room temperature was successfully fabricated on a nanostructured silicon surface. The local electrical field distribution was investigated with an electrostatic force microscope. The sensing mechanism was attributed to the local electrical field enhancement on the nanostructure. When different biases were applied to the sensor, it showed different responses to carbon monoxide gas and ammonia gas. The nanostructured sensor also works at temperatures between 100°C to 200°C similar to the traditional gas sensor presently used. Sensor surface treatment has been carried with femtosecond laser irradiation, and the experiments have shown that the irradiation further increases the gas sensitivity from 0.89% to 1.59% for CO gas concentration as low as 18 ppm.