1. Sustainable and Efficient Light Patches for Future Illumination
Ludvig Edman

2. The light-emitting electrochemical cell (LEC)
Area-emissive thin-film device driven by low voltage of battery
Active material: blend of organic semiconductor (OSC) & mobile ions
OSC chemical structure → energy gap → emission color: “All” colours demonstrated with LECs including white
Redistribution of mobile ions during operation → formation of p-n junction doping structure
→ LECs can comprise solely air-stabile materials, which dissolve in liquids to form inks
Low-cost & energy-efficient solution fabrication: slot-die and spray-coating & inkjet printing
→ Metal-free devices & emission from functional/novel surfaces: plastic, metal, copy-paper, textile, stainless-steel fork!

3. The project and applications
Part 1: We recently demonstrated record-high efficiency (EQE 18.5 %) at strong brightness (>1000 cd/m2), but Ir- based OSC carries high cost and poor sustainability
Solution: Efficient all-organic OSC featuring (newly discovered) “thermally activated delayed fluorescence”
Part 2: Solution-based fabrication of entire device, but deposition of large-area top electrode results in high voltage and poor stability
Solution: Bilayer top electrode: upper layer contributing high conductivity and lower layer being electrochemically and chemically stabile in in contact with active material
Applications:
Short-term: devices with designed features for medtech (emissive band-aids/blankets: jaundice in infants) and communication/advertising (light-emission stickers) that can be easily recycled
Long-term: efficient and low-cost illumination panels with desired architectural features (thin, light-weight, flexible) and which feature glare-free area emission

4. Tack!