High-Performing Polycrystalline MoS2-Based Microelectromechanical Piezoresistive Pressure Sensor

Abstract

The research toward high-performing pressure sensors has been going on for more than two decades, with the goal of improving key parameters, namely the high gauge factor (GF) and device stability for future applications. In the present work, the piezoresistivity of the polycrystalline molybdenum disulfide (MoS2) is harnessed for pressure sensing applications with very low noise levels. The fabricated microelectromechanical systems (MEMS) pressure sensor exhibits a high GF of ~92 with pressure sensitivity of ~ <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$0.46 \mu \text{A}$ </tex-math></inline-formula> /Pa and a low nonlinearity of ~12% in the applied pressure range 0–20 kPa. This exceptional performance is explained based on fluctuation-induced tunneling in the polycrystalline MoS2-based pressure sensor. The tunneling barrier between two grains gets modified with the application of external pressure. Furthermore, the noise analysis of the fabricated MEMS pressure sensor shows that the noise level gets altered with the applied stress due to the modified barrier potential.