High-Resolution Self-Organized OLED Materials for Printable Electronic Devices – Resolve

The Resolve project brings together three complementary teams from France and Taiwan to tackle the future of large-area printable OLED devices. The project relies on the expertise in OLED materials and organic synthesis of K.T. Wong from NTU, one of the most successful teams worldwide in this field that has received numerous prizes for their achievements. They will prepare small molecule electroluminescent materials designed to self-assemble via hydrogen-bonding interactions thanks to biuret molecular recognition groups. These are capable of directing the formation of extended sheets that spontaneously form vesicles when dispersed in solution. Two teams from France, one specialized in supramolecular photochemistry (ISM) and one specialized in the fabrication and characterization of organic electronics devices (IMS). The ISM team is lead by D. Bassani, a recognized expert in the area of photochemistry (currently Editor-in-Chief for the RSC journal Photchem. Photobiol. Sci.), and widely known for his work on supramolecular systems. The IMS team is lead by L. Hirsh, who launched and directed the French GDR in organic electronics for several years. The three teams have a long history of collaborative work and were able, during the course of a previous international project, to demonstrate the fabrication of the first supramolecular OLED device in which the three RGB colors were co-deposited in very close proximity (< 1 µm2). This allows, in principle, to envision OLED devices whose resolution can reach 20000 dpi. In the Resolve project, we will take this much beyond the current state-of-the-art by developing systems that can spontaneously self-sort from the same solution into separate aggregates of different colors. This will not only allow us to prepare multi-color pixel active layers in one single deposition, but will also allow error correction during the deposition of individual colors, should any one color bleed into the adjacent pixel. Other advanced functionalities will also be implemented using supramolecular building blocks as a means to a functions-based approach to future OLED devices. These will be investigated at the photophysical level using advanced time- and spaced-resolved confocal microscopy. We have modified our instrument to collect electroluminescence mapping images and it is now coupled to a conductive AFM for in-depth measurements. Finally, we will concentrate on the development of solution-based printing techniques that are compatible with current manufacturing protocols. These include state-of-the-art ink-jet printing available at the ELORPrintTec clean room facilities that will allow us to prepare large-area devices and study the effects of ink composition and deposition conditions on the self-assembly processes and device performance. This project is directly linked to the LabEx AMADeus.