Ultrathin silicon nanowires (SiNWs), grown via a high-yield and low-cost catalytic approach, are ideal building blocks for the construction of highly sensitive field-effect transistor (FET) sensors. In this work, we demonstrate a high-density growth integration of an ultrathin SiNW array, with diameter down to D_NW = 24 ± 3 nm and narrow NW-to-NW spacing of only 120 nm, fabricated via an in-plane solid–liquid–solid (IPSLS) approach. Junctionless bottom-gated SiNW FETs are successfully constructed, exhibiting a high on/off current ratio of >10⁷ and a sharp subthreshold swing of 156 mV/dec These provide an excellent platform for realizing high-performance NH₃ sensing at room temperature, with a high response of 96.9% at 25 ppm and 38.6% at 2.5 ppm, rapid response time of 7.9 s for 5% response (or 85.8 s for 50% response), and superior selectivity against common volatile organic compound gases in ambient environments. Finally, the field-effect sensing mechanism is attributed to the Schottky barrier modulation by the adsorbed NH₃ molecules at the metal/SiNW interface, as confirmed through an epoxy-masked selective region comparative analysis. These results provide a solid basis for the ultrathin catalytic IPSLS-SiNWs to serve as advantageous one-dimensional (1D) channels for the scalable integration of various high-performance and flexible gas sensing applications.

中文翻译：

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基于高密度和超薄硅纳米线通道的高性能氨场效应传感


超薄硅纳米线 （SiNW） 通过高产量和低成本的催化方法生长，是构建高灵敏度场效应晶体管 （FET） 传感器的理想构建模块。在这项工作中，我们展示了超薄 SiNW 阵列的高密度生长集成，直径低至 D_NW = 24 ± 3 nm，NW 到 NW 间距仅为 120 nm，通过面内固-液-固 （IPSLS） 方法制造。成功构建了无结底部门控 SiNW FET，具有 >10⁷ 的高开/关电流比和 156 mV/dec 的急剧亚阈值摆幅这些为在室温下实现高性能 NH₃ 传感提供了出色的平台，在 25 ppm 时具有 96.9% 的高响应，在 2.5 ppm 时具有 38.6% 的高响应，5% 响应时的快速响应时间为 7.9 秒（或 50% 响应时为 85.8 秒）， 对周围环境中常见的挥发性有机化合物气体具有卓越的选择性。最后，场效应感应机制归因于金属/SiNW 界面处吸附的 NH₃ 分子的肖特基势垒调制，这通过环氧树脂掩蔽的选择性区域比较分析得到证实。这些结果为超薄催化 IPSLS-SiNW 作为有利的一维 （1D） 通道，用于各种高性能和灵活的气体传感应用的可扩展集成提供了坚实的基础。