Design of MoS2/graphene heterostructure thin film sensors for high performance NO2 gas sensor applications

Abstract

In this paper, we fabricate a large-area chemiresitive type MoS2/graphene films sensor is grown by spray pyrolysis technique. The prepared sensor films were characterization by XRD, SEM, TEM Raman and BET analysis. The synergistic effect between MoS2 and graphene through the CVD method produces such a hierarchical layer-by-layer assembly of the thin film structure. MoS2/graphene hybrid films not only show enhanced NO2 sensitivity compared to NO2 sensitivity alone. Graphene or MoS2 films, but they also exhibit characteristics of rapid response and strong reproducibility. Selectiveness and stability findings demonstrate the outstanding sensing properties of the MoS2 thin film sensor. The MoS2/G showed higher sensitivity (81%) towards NO2 gas at the concentration of 1000 ppm followed by graphene (22 %) and MoS2 (45 %) based sensors in sequence. The MoS2/G sensor also exhibits fast response (12 s) and recovery time (17 s) than other sensor samples. The concept of operation and sensing mechanism behind their impressive results has also been studied in depth. The effect of humidity on the performance of gas sensing was also discussed in the point of practical device applications.