Fast response hydrogen sensors based on palladium and platinum/porous 3C-SiC Schottky diodes

Porous 3C-SiC (pSiC) samples with an average pore diameter of 30 nm were prepared by electrochemical anodization. Planar type Schottky diodes were fabricated using 1-mm diameter Au contact metal where the Au dot was chemically modified via the sputtering of Pd and Pt for use as a hydrogen catalyst. Changes in the current were monitored with respect to hydrogen concentration in the range of 10–40 ppm with a 3.7 V forward bias. The variations in current in the presence of hydrogen demonstrated that Pd and Pt/Au/pSiC samples have the ability to detect hydrogen. In the case of Pd, the response and recovery time at room temperature were 2.3 and 1.5 s, respectively. A large change in current was observed with the Pd catalyst, and the hydrogen sensing performance improved at high temperatures.