A hydrogen sensing Pd/InGaP metal-semiconductor (MS) Schottky diode hydrogen sensor

Abstract

An interesting hydrogen sensing Pd/InGaP metal-semiconductor (MS) Schottky diode has been fabricated and studied. Both the steady state and the transient condition of the hydrogen adsorption process are investigated. Even at room temperature, an extremely low hydrogen concentration of 15 ppm H2/air can be detected. In addition, the wide operating temperature range of 250 K of the studied Pd/InGaP hydrogen sensor is found. From experimental results, it is shown that the variation of Schottky barrier height increases with the increase of the operating temperature and hydrogen concentration. As the operation temperature is elevated, the water formation effect is also studied in the quasi-equilibrium region under the transient condition.