Solution Deposition Methods for Carbon Nanotube Field-Effect Transistors

摘要

This study evaluated different methods for controlled deposition of carbon nanotubes (CNTs) from solution onto a silicon substrate to make CNT field-effect transistors (FETs). The goal of this deposition was to achieve reproducible device properties through more uniform CNT densities and other traits. This method serves as an easier, room temperature alternative to chemical vapor deposition growth. Three different types of CNT solutions were spun onto substrates: pristine tubes solubilized with surfactant, COOH- functionalized tubes, and aminopyrene non-covalently functionalized tubes. Characterization of the CNT films was done with scanning electron microscopy. The CNTs were processed into FETs using standard microelectronics processing techniques. The resulting devices were characterized using a semiconductor parameter analyzer to measure their electrical properties. Preliminary results showed that the aminopyrene non-covalently functionalized CNTs were better dispersed and centrifugation could remove agglomerated tubes from the solution prior to spin-coating. A comparison of the results for each deposition method will help to determine which conditions are useful for producing CNT devices for chemical sensing and electronic applications.