Effect of Nb Doping on Chemical Sensing Performance of Two-Dimensional Layered MoSe.

Here, we report that Nb doping of two-dimensional (2D) MoSe layered nanomaterials is a promising approach to improve their gas sensing performance. In this study, Nb atoms were incorporated into a 2D MoSe host matrix, and the Nb doping concentration could be precisely controlled by varying the number of NbO deposition cycles in the plasma enhanced atomic layer deposition process. At relatively low Nb dopant concentrations, MoSe showed enhanced device durability as well as NO gas response, attributed to its small grains and stabilized grain boundaries. Meanwhile, an increase in the Nb doping concentration deteriorated the NO gas response. This might be attributed to a considerable increase in the number of metallic NbSe regions, which do not respond to gas molecules. This novel method of doping 2D transition metal dichalcogenide-based nanomaterials with metal atoms is a promising approach to improve the performance such as stability and gas response of 2D gas sensors.