Development of Pd-Pt functionalized high performance H2 gas sensor based on silicon carbide coated porous silicon for extreme environment applications

Present work demonstrates the hydrogen gas (H-2) sensing characteristics of palladium-platinum (Pd-Pt) functionalized silicon carbide (SiC) thin film grown on porous silicon (PSi) substrate for high temperature applications. Nano-crystalline SiC thin film was deposited by RF magnetron sputtering on anodized PSi substrate. The loading of discrete ultra-thin Pd-Pt bimetallic catalytic layer was carefully controlled by varying the sputtering parameters. The proposed device architecture (Pd-Pt/SiC/PSi) revealed significant advantages, such as stable high sensing response, large tunable detection range (5-500 ppm), fast response/recovery time, excellent reproducibility, high selectivity, wide operating temperature regime (25-500 degrees C) and good durability. The observed high response may be ascribed to the combined effect of enhanced catalytic activity of bimetallic Pd-Pt layer and increased surface area of the proposed sensor.