Hydrogen gas sensor of Pd-functionalised AlGaN/GaN heterostructure with high sensitivity and low-power consumption

A Pd-functionalised hydrogen gas sensor based on an AlGaN/GaN heterostruture platform was investigated. The optimum bias voltage and reaction temperature were 0.1 V and 200°C, respectively, with which a wide range of hydrogen concentration from 0.1-4% in the air (i.e. 1000-40,000 ppm) was detectable. Not only low-power consumption but also high sensitivity with fast response was achieved due to the excellent properties of the AlGaN/GaN heterostructure platform. The sensitivity was 72.8% with a response time of ∼3 s in 4% hydrogen concentration.