Song, Young Geun Shim, Young-Seok Suh, Jun Min Noh, Myoung-Sub Kim, Gwang Su Choi, Kyoung Soon Jeong, Beomgyun Kim, Sangtae Jang, Ho Won Ju, Byeong-Kwon Kang, Chong-Yun 2024-01-19T19:03:57Z 2024-01-19T19:03:57Z 2021-09-02 2019-10 1613-6810 https://pubs.kist.re.kr/handle/201004/119545 The development of high performance gas sensors that operate at room temperature has attracted considerable attention. Unfortunately, the conventional mechanism of chemiresistive sensors is restricted at room temperature by insufficient reaction energy with target molecules. Herein, novel strategy for room temperature gas sensors is reported using an ionic-activated sensing mechanism. The investigation reveals that a hydroxide layer is developed by the applied voltages on the SnO2 surface in the presence of humidity, leading to increased electrical conductivity. Surprisingly, the experimental results indicate ideal sensing behavior at room temperature for NO2 detection with sub-parts-per-trillion (132.3 ppt) detection and fast recovery (25.7 s) to 5 ppm NO2 under humid conditions. The ionic-activated sensing mechanism is proposed as a cascade process involving the formation of ionic conduction, reaction with a target gas, and demonstrates the novelty of the approach. It is believed that the results presented will open new pathways as a promising method for room temperature gas sensors. English WILEY-V C H VERLAG GMBH HUMIDITY SENSORS SENSITIVITY PRINCIPLE INTERNET THINGS Ionic-Activated Chemiresistive Gas Sensors for Room-Temperature Operation Article 10.1002/smll.201902065 1 SMALL, v.15, no.40 SMALL 15 40 scie scopus 000478826800001 2-s2.0-85070489817 Chemistry, Multidisciplinary Chemistry, Physical Nanoscience & Nanotechnology Materials Science, Multidisciplinary Physics, Applied Physics, Condensed Matter Chemistry Science & Technology - Other Topics Materials Science Physics Article HUMIDITY SENSORS SENSITIVITY PRINCIPLE INTERNET THINGS gas sensors humidity ionic conduction NO2 room temperature