Highly Enhanced H(2) Sensing Performance of Few-Layer MoS(2)/SiO(2)/Si Heterojunctions by Surface Decoration of Pd Nanoparticles

A novel few-layer MoS(2)/SiO(2)/Si heterojunction is fabricated via DC magnetron sputtering technique, and Pd nanoparticles are further synthesized on the device surface. The results demonstrate that the fabricated sensor exhibits highly enhanced responses to H(2) at room temperature due to the decoration of Pd nanoparticles. For example, the Pd-decorated MoS(2)/SiO(2)/Si heterojunction shows an excellent response of 9.2 × 10(3)% to H(2), which is much higher than the values for the Pd/SiO(2)/Si and MoS(2)/SiO(2)/Si heterojunctions. In addition, the H(2) sensing properties of the fabricated heterojunction are dependent largely on the thickness of the Pd-nanoparticle layer and there is an optimized Pd thickness for the device to achieve the best sensing characteristics. Based on the microstructure characterization and electrical measurements, the sensing mechanisms of the Pd-decorated MoS(2)/SiO(2)/Si heterojunction are proposed. These results indicate that the Pd decoration of few-layer MoS(2)/SiO(2)/Si heterojunctions presents an effective strategy for the scalable fabrication of high-performance H(2) sensors. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1186/s11671-017-2335-y) contains supplementary material, which is available to authorized users.