Metal Inks
Metal films have numerous applications in devices manufactured through roll-to-roll process and for solar cells and printed electronics this is typically as a conductor. The work being undertaken at the Conn Center with this technology is geared towards developing stable inks of metal nanoparticles using water based solvents. These inks are capable of being processed using intense pulsed light and incorporated into devices such as flexible electronics and solar cells.
Schematic of CuO ink formulations. A) micellular preparation using copper salts and capping agent in a water dispersion, B) addition of sodium boro hydroxide as a reductant affect particle size
The push for distributed light weight and small devices invariably requires the use of metal traces as interconnects, antennas, and etc. Printing these materials using inks in high speed processes offers a huge opportunity to reduce costs. Metals such as copper have other challenges such as solution stability and oxidation that must be overcome to make them commercially viable in these applications. Our group is interested in developing metal nanoparticle inks for incorporation into printed electronic devices especially solar cells with current work focusing on:
- Water based copper inks,
- Rapid sintering using intense pulsed light,
- Application as a current collector for solar cells.
The nanoparticle inks we have developed rely on oxide shells that can be reduced during the post-processing. These can be simply synthesized using water based chemistries at ambient conditions where the products do not necessarily need to be separated from the vehicle to establish the ink. Other additives incorporated into the inks during synthesis and/or formulation will assist in the reduction of the oxides to form highly conductive patterned films.