Air-stable, all-dry transferred ReS2/GaSe heterostructure-based NO2 gas sensor

Two-dimensional (2D) materials have gained considerable attention in chemical sensing owing to their naturally high surface-to-volume ratio. However, the poor response time and incomplete recovery restrict their application in practical, high performance gas sensors. In this work, we fabricated air-stable ReS2/GaSe heterostructure-based NO2 gas sensors with excellent gas sensing response, recovery, selectivity and a low limit of detection (LOD) toward nitrogen dioxide (NO2). The ReS2/GaSe heterostructure was prepared via mechanical exfoliation and an all-dry transfer method. Before the sensing measurements, temperature-dependant transport measurements were carried out. The Schottky Barrier Height (SBH) of the ReS2 /GaSe heterostructure was calculated and the corresponding transport mechanisms were discussed. The fabricated gas sensors showed a significant response enhancement with full reversibility toward ppm-level NO2 (response of similar to 17% at 3 ppm, a LOD of similar to 556 ppb) at an operating temperature of (33 degrees C). In particular, the total response and recovery time of the ReS2/GaSe was revealed to be less than 4 min (similar to 38 s and similar to 174 s, respectively) for the 250 ppm concentration, which is one of the best response and recovery time toward ppm-level NO2. The excellent sensing performances and recovery characteristics of the ReS2/GaSe structure are attributed to its efficient charge separation, unique interlayer coupling and desirable band alignments. This atomically thin, ultrasensitive gas sensor that operates at room temperature is a strong technological contender to conventional metal oxide gas sensors, which often require elevated temperatures. (c) 2023 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science & Technology.