Impact of defects in self-assembled monolayer on humidity sensing by molecular functionalized transistors. (13th April 2020)

• Record Type: Journal Article
• Authors: Tanaka, Takahisa; Yajima, Takeaki; Uchida, Ken
• Is Part Of: Japanese journal of applied physics. Volume 59:Number SI(2020)
• Publication Date: 2020-04-13
• Subjects: gas sensor -- molecular dynamics -- transistor; Physics -- Periodicals; 621.05
• DOI: 10.35848/1347-4065/ab80dc
• Languages: English
• ISSNs: 0021-4922

Abstract

Abstract: For highly sensitive and selective sensors, numerical study of transistors functionalized with a defected self-assembled monolayer (SAM) was performed. Adsorption of water molecules on the defected SAM was treated by molecular dynamics (MD) calculations. Based on time dependent atomic positions and charges derived from the MD calculations, carrier concentration and threshold voltage of defected-SAM-functionalized transistors were derived from the Poisson equation. The defects of the SAM caused a penetration of water molecules. Due to a strong polarization of water molecules, the water molecules penetrating the defects were stacked in the same direction. The alignment of the water molecules in the defects generated a large electrical dipole, and the threshold voltage of the transistors were shifted.