Electrodeposited Pt/InP Schottky barriers with large barrier heights and large hydrogen sensitivity for sensor chips using InP-based uantum wire networks [uantum read quantum]

Pt Schottky diodes were fabricated on n-InP by pulsed electrodeposition, and their H₂ sensing properties were investigated. Deposition resulted in formation of Pt nanoparticles. As compared with diodes by vacuum deposition, electrodeposited diodes gave much higher Schottky barrier heights (SBHs) of 810 meV. They showed marked increase of the reverse current on exposure to H₂ gas in air. The magnitudes of current change and on-off transients depended on the partial pressure of H₂. The detection mechanism is explained in terms of SBH change caused by adsorption/desorption of atomic hydrogen at the Pt/semiconductor interface. Its behavior was strongly affected by the presence of oxygen in the atmosphere. Integration of the present sensor with a hexagonal quantum wire network is proposed for realization of a wireless hydrogen sensor chip