Efficient, durable, and reliable light emitting diodes (LEDs) of desired shape, size, color and flexibility for solid-state lighting is a major area of current research and industrial interest. In particular, Polymer Light Emitting Diodes (PLEDs), show great promise as candidates for future lighting applications due to their high processability, simple construction and large-area coverage.
Serving this purpose, we have [1,2] concentrated on the development of soluble, scalable, high molecular weight and film-forming fluorescent aromatic polyethers without the use of precious metal catalysts during the polymerization or the need for tedious purification processes. Using combinations of blue, yellow, and orange-red fluorescent organic semiconductors, polymers of controllable and stable light emissions are obtained. Additionally, high molecular weight polymeric phosphors based on iridium complexes have been developed [3] to exploit the triplet excitons of Ir-based complexes.
To enhance the sustainability of these fluorescent polysulfones, water/alcohol solubilizing units are utilized to meet the green and eco-friendly solubility requirements for the fabrication of PLED devices. In all cases, the polymers’ solubility in polar non-chlorinated solvents (eg DMF, NMP) or “greener/renewable” ones (eg γ-Valerolactone, TamiSolve, 2-MeTHF, water, ethanol) has been studied to set the basis for greener alternatives as photoactive materials.
Ultimately, fine-tuning the emitted light color is achieved covering the entire visible spectrum or even affording white light emission, while the polymers’ high molecular weights and enhanced solubility, allow their deposition and printing from solutions thus, paving the way for printable wide-panel and signaging PLEDs.
References
1. Andrikopoulos, K. C.; Anastasopoulos, C.; Tselekidou, D.; Papadopoulos, K.; Kyriazopoulos, V.; Laskarakis, A.; Logothetidis, S.; Kallitsis, J. K.; Gioti, M.; Andreopoulou, A. K. Fluorescent Aromatic Polyether Sulfones: Processable, Scalable, Efficient, and Stable Polymer Emitters and Their Single-Layer Polymer Light-Emitting Diodes. Nanomaterials, 2024, 14 (15), 1246. DOI: 10.3390/nano14151246
Acknowledgements
This research has been co‐financed by the Greece 2.0-National Recovery and Resilience Fund: "Development of efficient third generation PV materials and devices to enhance the competitiveness of enterprises to the green energy production"_3GPV-4INDUSTRY. TAEDR-0537347, and by the European Union and Greek national funds through the Operational Program Competitiveness, Entrepreneurship, and Innovation, under the call RESEARCH – CREATE – INNOVATE (project code:T1EDK-01039 “Printed OLEDs for Intelligent, Efficient & Tunable solid-state lighting devices in Large Scale”, APOLLON.