The low-frequency noise is of special interest for carbon nanotubes devices, which are building blocks for a variety of sensors, including radio frequency and terahertz detectors. We studied noise in as-fabricated and aged carbon nanotube networks (CNNs) field-effect transistors. Contrary to the majority of previous publications, as-fabricated devices demonstrated the superposition of generation-recombination (GR) and 1/f noise spectra at a low-frequency range. Although all the devices revealed identical current–voltage characteristics, GR noise was different for different transistors. This effect is explained by the different properties and concentrations of trap levels responsible for the noise. Unexpectedly, exposure of these devices to the atmosphere reduced both the resistance and GR noise due to nanotube's p-doping by adsorbed water molecules from the ambient atmosphere. The presence of the generation recombination noise and its dependences on the environment provides the basis for selective gas sensing based on the noise measurements. Our study reveals the noise properties of CNNs that need to be considered when developing carbon nanotubes-based selective gas sensors.

中文翻译：

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碳纳米管网络中的生成-重组和 1/fnoise

低频噪声对碳纳米管器件特别感兴趣，碳纳米管器件是各种传感器的构建块，包括射频和太赫兹探测器。我们研究了制造和老化的碳纳米管网络 (CNN) 场效应晶体管中的噪声。与以前的大多数出版物相反，制造的设备证明了生成重组 (GR) 和 1/ f低频范围内的噪声频谱。尽管所有器件都显示出相同的电流-电压特性，但不同晶体管的 GR 噪声是不同的。这种效应是由引起噪声的陷阱级别的不同属性和浓度来解释的。出乎意料的是，由于从环境大气中吸附的水分子对纳米管进行p掺杂，因此将这些器件暴露在大气中会降低电阻和 GR 噪声。生成重组噪声的存在及其对环境的依赖性为基于噪声测量的选择性气体传感提供了基础。我们的研究揭示了在开发基于碳纳米管的选择性气体传感器时需要考虑的 CNN 的噪声特性。