Electrostatic atomization of carbon nanotube (CNT) films for thin film transistor (TFT) gas sensors for defence applications

• Main Author: Ong, Weiying.
• Other Authors: Alfred Tok Iing Yoong
• Format: Final Year Project
• Language: English
• Published: 2009
• Subjects: DRNTU::Engineering::Mechanical engineering
• Online Access: http://hdl.handle.net/10356/19072
• Institution: Nanyang Technological University

Various research papers have shown that Electrostatic Atomization (EA) is capable of producing monodispersed and self-assembled nanostructures. These provided a platform for future exploration of its potential in creating a monodispersed SWCNTs based channel for transistor. In this report, the novel deposition of varying types of functionalized Single Walled Carbon Nanotubes (SWCNTs) on the silicon channel for thin film transistor for gas sensing application is accounted for. Stable dispersion of three different types of SWCNTs is achieved in both ethyl alcohol and water. Such dispersion is attained with via covalent functionalization, metal ion reduction or addition of surfactant. Intricate balance of liquid properties and experimental variables, namely flow rate and applied voltage, is achieved to obtain stable cone-jet mode for electrospraying of the experimental solutions. While applied voltage and flow rate is found to govern the establishment of cone-jet mode and droplet size respectively, nature of experimental solution and duration of spray determines the conduction pathway of the transistor. Resistance values and output characteristics were taken to ensure feasibility of EA deposited devices. Comparison with conventional drop cast and chemical vapor deposition was drawn to show how EA could possibly overcome their limitations.