Piezoresistive strain sensor based on monolayer molybdenum disulfide continuous film deposited by chemical vapor deposition

In this paper, a centimeter-scale monolayer molybdenum disulfide (MoS₂) film deposition method has been developed through a simple low-pressure chemical vapor deposition (LPCVD) growth system. The growth pressure dependence on film quality is investigated in this LPCVD system. The layer nature, electrical characteristic of the as-grown MoS₂ films indicate that high quality films have been achieved. In addition, a hydrofluoric acid treated SiO₂/Si substrate is used to improve the quality of the MoS₂ films. Piezoresistive strain sensor based on the monolayer MoS₂ film elements is fabricated by directly patterning metal contact pads on MoS₂ films through a silicon stencil mask. A gauge factor of 104 - 26 under compressive strain is obtained by using a four-point bending method, which may inspire new possibilities for two-dimensional (2D) material-based microsystems and electronics.