Zhao Shufen, Li Zhengcao, Wang Guojing, Liao Jiecui, Lv Shasha, Zhu Zhenan
State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University Beijing 100084 China
Key Laboratory of Advanced Materials (MOE), School of Materials Science and Engineering, Tsinghua University Beijing 100084 China.
RSC Adv. 2018 Mar 21;8(20):11070-11077. doi: 10.1039/c7ra13484c. eCollection 2018 Mar 16.
Molybdenum disulfide/porous silicon nanowire (MoS/PSiNW) heterojunctions with different thicknesses as highly-responsive NO gas sensors were obtained in the present study. Porous silicon nanowires were fabricated using metal-assisted chemical etching, and seeded with different thicknesses. After that, MoS nanosheets were synthesized by sulfurization of direct-current (DC)-magnetic-sputtering Mo films on PSiNWs. Compared with the as-prepared PSiNWs and MoS, the MoS/PSiNW heterojunctions exhibited superior gas sensing properties with a low detection concentration of 1 ppm and a high response enhancement factor of ∼2.3 at room temperature. The enhancement of the gas sensitivity was attributed to the layered nanostructure, which induces more active sites for the absorption of NO, and modulation of the depletion layer width at the interface. Further, the effects of the deposition temperature in the chemical vapor deposition (CVD) process on the gas sensing properties were also discussed, and might be connected to the nucleation and growth of MoS nanosheets. Our results indicate that MoS/PSiNW heterojunctions might be a good candidate for constructing high-performance NO sensors for various applications.
在本研究中制备了具有不同厚度的二硫化钼/多孔硅纳米线（MoS₂/PSiNW）异质结作为高响应性NO气体传感器。多孔硅纳米线通过金属辅助化学蚀刻制备，并具有不同的厚度。之后，通过在PSiNWs上对直流（DC）磁控溅射Mo膜进行硫化来合成MoS₂纳米片。与制备的PSiNWs和MoS₂相比，MoS₂/PSiNW异质结在室温下具有优异的气敏性能，检测浓度低至1 ppm，响应增强因子高达约2.3。气敏性的增强归因于层状纳米结构，它诱导了更多用于吸收NO的活性位点，并调节了界面处的耗尽层宽度。此外，还讨论了化学气相沉积（CVD）过程中的沉积温度对气敏性能的影响，这可能与MoS₂纳米片的成核和生长有关。我们的结果表明，MoS₂/PSiNW异质结可能是构建用于各种应用的高性能NO传感器的良好候选材料。
