Choi Hee-Jung, Kwon Soon-Hwan, Lee Won-Seok, Im Kwang-Gyun, Kim Tae-Hyun, Noh Beom-Rae, Park Sunghoon, Oh Semi, Kim Kyoung-Kook
Department of Advanced Convergence Technology, and Research Institute of Advanced Convergence Technology, Korea Polytechnic University, 237 Sangidaehak-ro, Siheung-si 15073, Korea.
Department of Nano & Semiconductor engineering, Korea Polytechnic University, 237 Sangidaehak-ro, Siheung-si 15073, Korea.
Nanomaterials (Basel). 2020 Mar 4;10(3):462. doi: 10.3390/nano10030462.
Prolonged exposure to NO can cause lung tissue inflammation, bronchiolitis fibrosa obliterans, and silo filler's disease. In recent years, nanostructured semiconducting metal oxides have been widely used to fabricate gas sensors because of their unique structure and surface-to-volume ratio compared to layered materials. In particular, the different morphologies of ZnO-based nanostructures significantly affect the detection property of NO gas sensors. However, because of the large interaction energy of chemisorption (1-10 eV), metal oxide-based gas sensors are typically operated above 100 °C, overcoming the energy limits to attain high sensitivity and fast reaction. High operating temperature negatively affects the reliability and durability of semiconductor-based sensors; at high temperature, the diffusion and sintering effects at the metal oxide grain boundaries are major factors causing undesirable long-term drift problems and preventing stability improvements. Therefore, we demonstrate NO gas sensors consisting of ZnO hemitubes (HTs) and nanotubes (NTs) covered with TiO nanoparticles (NPs). To operate the gas sensor at room temperature (RT), we measured the gas-sensing properties with ultraviolet illumination onto the active region of the gas sensor for photoactivation instead of conventional thermal activation by heating. The performance of these gas sensors was enhanced by the change of barrier potential at the ZnO/TiO interfaces, and their depletion layer was expanded by the NPs formation. The gas sensor based on ZnO HTs showed 1.2 times higher detection property than those consisting of ZnO NTs at the 25 ppm NO gas.
长时间暴露于一氧化氮会导致肺组织炎症、闭塞性细支气管炎和谷仓填充工病。近年来，纳米结构的半导体金属氧化物因其与层状材料相比具有独特的结构和表面积与体积比，已被广泛用于制造气体传感器。特别是，基于氧化锌的纳米结构的不同形态显著影响一氧化氮气体传感器的检测性能。然而，由于化学吸附的相互作用能较大（1-10电子伏特），基于金属氧化物的气体传感器通常在100°C以上工作，以克服能量限制以获得高灵敏度和快速反应。高工作温度对基于半导体的传感器的可靠性和耐久性有负面影响；在高温下，金属氧化物晶界处的扩散和烧结效应是导致不良长期漂移问题和阻碍稳定性提高的主要因素。因此，我们展示了由覆盖有二氧化钛纳米颗粒（NPs）的氧化锌半管（HTs）和纳米管（NTs）组成的一氧化氮气体传感器。为了在室温（RT）下操作气体传感器，我们通过对气体传感器的有源区域进行紫外线照射以进行光激活，而不是通过加热进行传统的热激活来测量气敏特性。这些气体传感器的性能通过氧化锌/二氧化钛界面处势垒的变化而增强，并且它们的耗尽层通过纳米颗粒的形成而扩展。在25 ppm的一氧化氮气体中，基于氧化锌半管的气体传感器的检测性能比由氧化锌纳米管组成的气体传感器高1.2倍。
