Electrohydrodynamic printing for scalable MoS₂ flake coating: Application to gas sensing device

Scalable sub-micrometer molybdenum disulfide (MoS₂) flake films with highly uniform coverage were created using a systematic approach. An electrohydrodynamic (EHD) printing process realized a remarkably uniform distribution of exfoliated MoS₂ flakes on desired substrates. In combination with a fast evaporating dispersion medium and an optimal choice of operating parameters, the EHD printing can produce a film rapidly on a substrate without excessive agglomeration or cluster formation, which can be problems in previously reported liquid-based continuous film methods. The printing of exfoliated MoS₂ flakes enabled the fabrication of a gas sensor with high performance and reproducibility for NO₂ and NH₃.