Room-temperature hydrogen-sensitive characteristics of Pd/boron doped amorphous carbon film/n-Si structure

We prepared Pd/boron doped amorphous carbon film/n-Si (Pd/B:a-C/n-Si) structure using direct current magnetron sputtering method. Capacitance–frequency curves of the as-prepared structure were investigated in air and hydrogen (H2) at room temperature (RT). It is found that the Pd/B:a-C/n-Si structure exhibits excellent H2 sensing properties such as high response (∼15%) and fast response time (∼170 s) and recovery time (∼325 s) for 100 ppm H2 in air at RT. The influence of n-Si resistivity and deposition temperature was also investigated. The sensing mechanism of the Pd/B:a-C/n-Si structure has also been discussed.