White light-emitting electrochemical cells based on metal-free TADF emitters
Tang, S., Tsuchiya, Y., Wang, J. et al. White light-emitting electrochemical cells based on metal-free TADF emitters. Nat Commun 16, 653 (2025). https://doi.org/10.1038/s41467-025-55954-3
The goal of this study was to demonstrate the first white light-emitting electrochemical cell (LEC) using solely metal-free thermally activated delayed fluorescence (TADF) emitters, targeting sustainable, efficient, and scalable illumination technologies.
Key findings showed that through precise tuning of the active material—combining two color-complementary TADF emitters, a blend host, and an ionic liquid electrolyte—a white TADF-LEC was fabricated that achieved a color rendering index (CRI) of 88, an external quantum efficiency (EQE) of 2.11%, and a luminance of 350 cd/m². The emission spectrum remained angle-invariant and stable over time. Importantly, the study proved that balanced charge transport and optimized energy transfer processes can yield high-quality white emission without relying on scarce or expensive metals.
Fluxim’s Setfos software was instrumental for optical modeling, particularly for simulating and determining the spatial distribution of the emissive p-n junction inside the device. By matching the modeled and measured angle-dependent electroluminescence spectra, Setfos enabled validation of optimal exciton generation and minimal quenching losses—accelerating device optimization with high precision.
These findings are important because they establish a sustainable path toward flexible, large-area lighting technologies that avoid the environmental and geopolitical issues associated with rare-metal-based devices, offering practical alternatives for future illumination and display applications.