Three-terminal-controlled resistor-type hydrogen sensor

A novel and interesting three-terminal-controlled active resistor-type hydrogen sensor, based on good properties in the linear region of an AlGaAs-based pseudomorphic high electron mobility transistor in combination with the catalytic Pd metal, is demonstrated. The experimental results show that the gate-source voltage V_GS exhibits significant influence on the hydrogen-sensing properties, including resistance sensitivity, detection limit of hydrogen concentration, conductance variation, current variation and dynamic response. Consequently, under an appropriate applied V_GS bias, a smart active resistor-type hydrogen sensor can be achieved.