ELECTRONINKS INCORPORATED — Department of Energy STTR Phase I: 09b

Description

Currently, indium tin oxide (ITO) is used as the transparent conductive anode in all commercial organic light emitting diodes (OLEDs). However, ITO has economic and technological limitations for OLEDs such as high cost, brittleness, and poor performance. The primary objective of this Small Business Technology Transfer (STTR) Phase I proposal is to demonstrate the microfluidic printing of substrate embedded metal microgrids with transmission over 90% in the visible range and sheet resistance less than 1 Ω/square over a 10 x 10 cm area with all processing at low temperatures (< 120◦ C). The approach will be to develop a microfluidic printing technology, which utilizes selective hydrophobic and hydrophilic areas in the substrate, to pattern the metal ink into high performance, flexible transparent electrodes. The technical tasks of Phase I are to (1) develop high performance metal inks and stretchable metal inks, (2) develop microfluidic printing methods that pattern metal inks directly into rigid glass and flexible plastic substrates,(3) perform simulations to design metal microgrids for high performance, and (4) characterize manufactured samples optically and electronically and characterize performance under repeated bending and stretching. The results of this work will target the commercial application of OLEDs. This technology may lower the costs and improve the efficiencies of OLEDs used in displays, wearables, and lighting. The transparent electrode technology may also be applicable to RF-ID tags, artificial skin, and the Internet of Things. This proposed substrate embedded microgrids are a new disruptive technology that has the potential to exceed the performance of ITO, the standard for commercial transparent conductors. The main innovation of the proposed technology is that grids with small widths (< 10 µm) and large thicknesses (> 10 µm) can all be printed at low temperatures with high throughput embedded into substrates that allow for subsequent organic layer deposition. The PIs will collaborate with OLEDWorks in Phase II on integrating, testing, and characterizing the microgrids with state-of-the-art OLEDs.