A sensitive NH3 sensor using MoSe2/SnO2 composite

In this paper, we show how to employ a sensitive and selective chemiresistive ammonia sensor based on p-MoSe2/n-SnO2 heterojunctions at ambient temperature. Significantly, when compared to MoSe2 (p-type) and SnO2 (n-type) counterparts, the composite-based sensor demonstrated n-type sensing behaviour and a considerable improvement in ammonia sensing. The device also demonstrated outstanding response-recovery characteristics throughout a wider range of ammonia concentrations, as well as a highly selective nature toward ammonia as compared to other analytes such as acetone, ethanol, and formaldehyde. Superior signal to noise ratio enabled ammonia detection down to 25 ppm and with advanced type device structures, detection far below this level can be achieved. Composite based device has shown a faster response of 63% for 100 ppm of ammonia. The current study demonstrates the possible use of composite-based heterojunctions for monitoring ammonia gas in real-world applications. (C) 2022 Elsevier Ltd. All rights reserved.