Dendri‐LEC Family: Establishing the Bright Future for Dendrimer Emitters in Traditional and Graphene‐Based Light‐Emitting Electrochemical Cells

A rational implementation and optimization of thermally activated delayed fluorescent (TADF) dendrimer emitters in light-emitting electrochemical cells (LECs) sets the Dendri-LEC family. They feature outstanding stabilities (90/1050 h for green/yellow devices) that are comparable to best Ir(III)-complexes (450/500 h) conjugated polymers (33/5500 h), while offering benefits low-cost synthesis easy upscaling. In particular, a fundamental molecular design capitalizes on exchanging peripheral substituents (tert-butyl vs methoxy) tune photophysical, electrochemical, morphological, ion conductivity features thin films is rationalized by temperature-dependent steady-state time-resolved emission spectroscopy, cyclic voltammetry, atomic force microscopy, impedance spectroscopy techniques. Herein, TADF mechanism associated reduced photoluminescence quantum yield, but an enhanced stability enables clarify device efficiency brightness (4.0 lm W−1@110 cd m−2 3.2 W−1@55 m−2) increased (90 1050 upon using methoxy groups. What more, this substitution excellent compatibility with biogenic electrolytes keeping performances (1.9 W−1@35 1300 graphene-devices achieve par figures traditional indium–tin oxide-devices. Overall, work establishes bright future toward highly stable truly sustainable lighting sources.