Room temperature ammonia sensing using MoSe2 nanostructures

Abstract

Two dimensional layered materials have become increasingly important due to their fascinating physical properties such as large electronic mobility, large surface-to-volume ratio and instantaneous response to the surrounding environment. Here, we report the successful use MoSe2 nanostructures as room temperature ammonia sensor. The two-terminal sensor device exhibited a relative response larger than 2% (10 ppm ammonia) together with quick on–off switching. When device was exposed to ammonia, electrical measurements revealed an increase of resistance, implying a p-type behavior of the MoSe2 nanostructures. The room temperature sensitivity is attributed to the electron transfer from adsorbed ammonia molecules, which leads to reduction in hole population inside p-type semiconducting MoSe2, thereby giving rise to increase in resistance of the underlying MoSe2 channel. These preliminary results indicate the importance of MoSe2 nanostructures as a sensitive room temperature probe for ammonia gas.