Abstract

Demand for the detection of carbon dioxide (CO₂) is increasing in various fields, including air-quality monitoring, health care, and agriculture. Smart gas sensors, in which micromachined gas sensors are integrated with driving circuits, are desirable for the social development of the internet of things. In this study, CO₂ sensors were fabricated and investigated. The sensors have LaNiSbWO₄-G-PPy (LNSW-G-Ppy) stacked layers as a sensing material in electrodes. A CO₂ response of 1.2 for a CO₂ concentration of 1800 ppm was obtained with a low power consumption (approximately 17 mW). This high response may have resulted from a significant contribution of the resistance component near the electrode. Optical characterizations confirmed that the LaNiSbWO₄-G-PPy gas sensor showed similar optical properties to a typical display device. From gas-sensing results, the LaNiSbWO₄-G-PPy gas sensor exhibited high response to CO₂ in concentration range of 200–4000 ppm at room temperature and high selectivity against CO₂. Furthermore, the LaNiSbWO₄-G-PPy gas sensors offer good repeatability, reproducibility, and measurement accuracy. A sensing mechanism of LaNiSbWO₄-G-PPy gas sensor was explained based on the resistance change of graphene sensing layer via a direct charge transfer process. These results could pave the way to develop a new type of gas sensor.

摘要

对二氧化碳 (CO ₂ )检测的需求在各个领域都在增加，包括空气质量监测、医疗保健和农业。将微机械气体传感器与驱动电路集成的智能气体传感器是物联网社会发展所需要的。在这项研究中，制造和研究了CO ₂传感器。传感器具有 LaNiSbWO ₄ -G-PPy (LNSW-G-Ppy) 堆叠层作为电极中的传感材料。甲CO ₂的1.2用于CO响应₂以低功耗（约 17 mW）获得 1800 ppm 的浓度。这种高响应可能是由于电极附近电阻分量的显着贡献造成的。光学特性证实，LaNiSbWO ₄ -G-PPy 气体传感器显示出与典型显示设备相似的光学特性。从气敏结果来看，LaNiSbWO ₄ -G-PPy 气体传感器在室温下对浓度范围为 200–4000 ppm 的CO ₂表现出高响应，并对 CO ₂具有高选择性。此外，LaNiSbWO ₄ -G-PPy 气体传感器具有良好的重复性、再现性和测量精度。LaNiSbWO _{4 的}传感机制-G-PPy 气体传感器基于石墨烯传感层通过直接电荷转移过程的电阻变化进行解释。这些结果可以为开发新型气体传感器铺平道路。