A new Pd-InP Schottky hydrogen sensor fabricated by electrophoretic deposition with Pd nanoparticles

In this letter, a new Pd-InP Schottky diode hydrogen sensor fabricated by electrophoretic deposition (EPD) combined with nanosized Pd particles is first proposed and demonstrated. Experimentally, the studied device exhibited excellent current-voltage rectifying characteristics with a large Schottky barrier height (SBH) of 829 meV. At 303 K, a high saturation sensitivity ratio of 38 was found under a very low hydrogen concentration of 15 ppm H/sub 2//air. As raising the hydrogen concentration to 1.0% H/sub 2//air, the SBH lowering of the studied devic"dq"e reached to 307 meV and the sensitivity ratio was high as 1.29/spl times/10/sup 5/ with a very rapid response, which far prevailed over those fabricated by the conventional thermal evaporation and electroless plating techniques. Consequentially, the EPD Pd-InP Schottky diode with extremely effective Pd gate is promising for the fabrication of high-performance hydrogen sensors.