Improving Performance and Stability of Solution-Processed Organic Poly-gridofluorene Light-Emitting Diodes via Deuterated Solvents.

Toluene and chloroform are widely utilized as solvents in optoelectronic device fabrication, but their carcinogenic properties and potential misuse in illicit drug synthesis subject them to strict state regulation. In contrast, their deuterated counterparts (toluene-d8 and chloroform-d) are not recognized as carcinogens by the World Health Organization's International Agency for Research on Cancer (IARC), presenting a safer alternative. Leveraging seawater-derived deuterium's natural abundance, we implemented these deuterated solvents for spin-coating superhindered poly-gridofluorene (PODPFG) emissive layers in solution-processed OLEDs. Comparative studies revealed that films fabricated with deuterated solvents demonstrated a nearly 26% enhancement in PLQY and improved luminescence stability. Notably, the devices showed increased external quantum efficiency from 0.72% to 1.12% while preserving deep blue color purity. These improvements are attributed to the formation of larger and ordered aggregates through enhanced intermolecular interactions in deuterated media, which promote optimal interchain aggregation. Our approach establishes a novel paradigm for isotope engineering in green manufacturing of solution-processed OLEDs, simultaneously addressing toxicity concerns and performance optimization through solvent-mediated morphological control for nontoxic, green manufacturing practices and industrial applications.