13.2: Electrochemical Deposition of Carbon Nanotube Films and Applications in Field Emission Display Devices

Abstract

AbstractAn electrochemical deposition (ECD) process for the formation of carbon nanotube (CNT) thin films on ITO coated glass is described. This simple and scalable process takes advantage of a highly stable aqueous dispersion of ribonucleic acids (RNA) wrapped CNTs reported previously. Thin films showing dense coverage of nanotubes can be prepared in a few minutes by the application of a few volts between a conductive substrate and a stainless steel counter electrode with both immersed in the RNA‐CNT aqueous dispersion. Patterned deposit with feature size of microns can be readily obtained by masking the conductive layer on the substrate. Since ECD is an additive process with efficient use of CNTs, it provides a cost effective alternative to photoimagable deposition. Unlike electrophoretic deposition, the ECD process is an aqueous, low voltage, and field independent process. Fringing field issues which can affect deposition uniformity on patterned surfaces are therefore avoided. for electron field emission applications such as display or backlight, ECD films can be sintered and surface treated to obtain highly emissive surfaces with low threshold voltage and high uniformity emission. The field emission performance of diode and triode devices prepared with ECD is discussed.