Non-halogenated solvent-processed TADF OLEDs with polymer-based exciplex hosts

We report high-performance green TADF OLEDs based on polymeric exciplex hosts that enable solution processing using non-halogenated solvents. Three biscarbazole-based p-type polymers (PC4-2Cz, PC8-2Cz, and PC12-2Cz) were synthesized with systematically varied alkylene spacers, achieving tunable solubility from halogenated aromatic to non-halogenated aliphatic solvents. When blended with tPDBA as the n-type component, the polymers formed stable exciplex hosts, enabling efficient green electroluminescence with maximum external quantum efficiencies (EQEs) up to 16.8%. Notably, devices fabricated using non-halogenated solvents such as toluene and 2-methyltetrahydrofuran exhibited performance comparable to those processed with chlorobenzene. These results highlight a sustainable molecular design strategy for scalable, environmentally friendly OLED fabrication without sacrificing device efficiency.