A Field Effect Based Hydrogen Sensor for Low and High Concentrations

Abstract

A silicon based semiconductor sensor structure Pd/LaF3/Si3N4/SiO2/Si was prepared using thin layer technology. The sensor can be used for hydrogen detection at room temperature. Therefore, the power consumption is reduced by a factor 106 compared to the best low power consumption hydrogen sensors. In contrast to other sensors it can be used for measurements at very low and high hydrogen partial pressure. The limit of detection was determined to be 0.5 ppm. Measurements at high concentrations near to and above the Lower Explosion Level (LEL) of 4 % hydrogen in air are demonstrated. A method to achieve long lifetime of the sensor was developed.