Khan Md Ashfaque Hossain, Rao Mulpuri V
Department of Electrical and Computer Engineering, George Mason University, Fairfax, VA 22030, USA.
Sensors (Basel). 2020 Jul 13;20(14):3889. doi: 10.3390/s20143889.
In the last two decades, GaN nanostructures of various forms like nanowires (NWs), nanotubes (NTs), nanofibers (NFs), nanoparticles (NPs) and nanonetworks (NNs) have been reported for gas sensing applications. In this paper, we have reviewed our group's work and the works published by other groups on the advances in GaN nanostructures-based sensors for detection of gases such as hydrogen (H), alcohols (R-OH), methane (CH), benzene and its derivatives, nitric oxide (NO), nitrogen dioxide (NO), sulfur-dioxide (SO), ammonia (NH), hydrogen sulfide (HS) and carbon dioxide (CO). The important sensing performance parameters like limit of detection, response/recovery time and operating temperature for different type of sensors have been summarized and tabulated to provide a thorough performance comparison. A novel metric, the product of response time and limit of detection, has been established, to quantify and compare the overall sensing performance of GaN nanostructure-based devices reported so far. According to this metric, it was found that the InGaN/GaN NW-based sensor exhibits superior overall sensing performance for H gas sensing, whereas the GaN/(TiO-Pt) nanowire-nanoclusters (NWNCs)-based sensor is better for ethanol sensing. The GaN/TiO NWNC-based sensor is also well suited for TNT sensing. This paper has also reviewed density-functional theory (DFT)-based first principle studies on the interaction between gas molecules and GaN. The implementation of machine learning algorithms on GaN nanostructured sensors and sensor array has been analyzed as well. Finally, gas sensing mechanism on GaN nanostructure-based sensors at room temperature has been discussed.
在过去二十年中，已报道了各种形式的氮化镓纳米结构，如纳米线（NWs）、纳米管（NTs）、纳米纤维（NFs）、纳米颗粒（NPs）和纳米网络（NNs），用于气体传感应用。在本文中，我们回顾了我们团队的工作以及其他团队发表的关于基于氮化镓纳米结构的传感器在检测氢气（H）、醇类（R-OH）、甲烷（CH）、苯及其衍生物、一氧化氮（NO）、二氧化氮（NO₂）、二氧化硫（SO₂）、氨（NH₃）、硫化氢（H₂S）和二氧化碳（CO₂）等气体方面的进展。总结并列出了不同类型传感器的重要传感性能参数，如检测限、响应/恢复时间和工作温度，以进行全面的性能比较。建立了一个新的指标，即响应时间与检测限的乘积，用于量化和比较迄今为止报道的基于氮化镓纳米结构的器件的整体传感性能。根据这个指标，发现基于InGaN/GaN NW的传感器在氢气传感方面表现出卓越的整体传感性能，而基于GaN/(TiO-Pt)纳米线-纳米团簇（NWNCs）的传感器在乙醇传感方面表现更好。基于GaN/TiO NWNC的传感器也非常适合三硝基甲苯传感。本文还回顾了基于密度泛函理论（DFT）的关于气体分子与氮化镓相互作用的第一性原理研究。还分析了机器学习算法在氮化镓纳米结构传感器和传感器阵列上的应用。最后，讨论了基于氮化镓纳米结构的传感器在室温下的气敏机理。
