Hydrogen sensing characteristics of Pd- and Pt-Al_0.3Ga_0.7As metal–semiconductor (MS) Schottky diodes

Abstract

Pd- and Pt-Al0.3Ga0.7As metal–semiconductor (MS) Schottky diodes are fabricated and studied. The hydrogen-sensing characteristics including Schottky barrier height modulations and hydrogen detection sensitivity and transient responses are investigated and presented. Due to the formation of hydroxyl at higher temperature, different transient responses are found for the studied Pt- and Pd-MS Schottky diodes. According to the van't Hoff equation, the initial heat of adsorption for the Pd- and Pt-Al0.3Ga0.7As MS interfaces is calculated as −5.21 and −7.56 kJ mole−1, respectively.