Fabrication and comparative analysis of the gas sensing devices based on individualized single-walled carbon nanotubes of four different types (pristine, boron doped, nitrogen doped, and semiconducting ones) for detection of low concentrations of ammonia is presented. The comparison of the detection performance of different devices, in terms of resistance change under exposure to ammonia at low concentrations combined with the detailed analysis of chemical bonding of dopant atoms to nanotube walls sheds light on the interaction of NH₃ with carbon nanotubes. Furthermore, chemoresistive measurements showed that the use of semiconducting nanotubes as conducting channels leads to the highest sensitivity of devices compared to the other materials. Electrical characterization and analysis of the structure of fabricated devices showed a close relation between amount and quality of the distribution of deposited nanotubes and their sensing properties. All measurements were performed at room temperature, and the power consumption of gas sensing devices was as low as 0.6 μW. Finally, the route toward an optimal fabrication of nanotube-based sensors for the reliable, energy-efficient sub-ppm ammonia detection is proposed, which matches the pave of advent of future applications.

中文翻译：

---

改进的单壁碳纳米管在室温下实现高灵敏度和高能效的氨气检测

介绍了基于四种不同类型（原始，掺杂硼，掺杂氮和半导体）的个性化单壁碳纳米管的气体传感装置的制造和比较分析，以检测低浓度的氨。比较不同设备的检测性能，就低浓度氨暴露下的电阻变化而言，以及对掺杂原子与纳米管壁化学键合的详细分析的结合，揭示了NH ₃的相互作用与碳纳米管。此外，化学电阻测量表明，与其他材料相比，使用半导体纳米管作为导电通道可导致器件的最高灵敏度。电学特征和对制成的器件结构的分析表明，沉积的纳米管分布的数量和质量与其感测特性之间存在密切的关系。所有测量均在室温下进行，气体传感设备的功耗低至0.6μW。最后，提出了一种优化制造基于纳米管的传感器以实现可靠，高能效的亚ppm级氨气检测的途径，这与将来的应用铺平了道路。