High-Performance Atomically-Thin Room-Temperature NO2 Sensor

• DOI: 10.1021/acs.nanolett.0c02221
• Publication Date: 2020-07-17T19:03:30Z
• Authors: Amin Azizi; Mehmet Dogan; Hu Long; Jeffrey D. Cain; Kyunghoon Lee; Rahmatollah Eskan...; Alessandro Varieschi; Emily C. Glazer; Marvin L. Cohen; Alex Zettl
• Keywords: Condensed Matter - Materials Science; Data Management and Data Science; Nitrogen Dioxide; Temperature; 500; Materials Science (cond-mat.mtrl-sci); FOS: Physical sciences; Humidity; layer-dependent electrical properties; 530; cond-mat.mtrl-sci; Engineering; Information and Computing Sciences; transition-metal dichalcogenides; Gases; Electronics; Sensors and Digital Hardware; two-dimensional materials; Nanoscience & Nanotechnology; room-temperature sensor

The development of room-temperature sensing devices for detecting small concentrations of molecular species is imperative for a wide range of low-power sensor applications. We demonstrate a room-temperature, highly sensitive, selective, and reversible chemical sensor based on a monolayer of the transition metal dichalcogenide Re0.5Nb0.5S2. The sensing device exhibits thickness dependent carrier type, and upon exposure to NO2 molecules, its electrical resistance considerably increases or decreases depending on the layer number. The sensor is selective to NO2 with only minimal response to other gases such as NH3, CH2O, and CO2. In the presence of humidity, not only are the sensing properties not deteriorated, but also the monolayer sensor shows complete reversibility with fast recovery at room temperature. We present a theoretical analysis of the sensing platform and identify the atomically-sensitive transduction mechanism.