Nonconjugated Polymer Flexibly Linked with Blue and Orange-Red Thermally Activated Delayed Fluorescence (TADF) Units for White Organic Light-Emitting Diodes (WOLEDs)

Single-component thermally activated delayed fluorescence (TADF) white-light-emitting polymers enable solution processing and suppress phase separation in white organic light-emitting diodes (WOLEDs). However, their development remains limited by emission color control and synthetic challenges. Here, a series of nonconjugated TADF polymers (PDFC-DT 100 – x -TB x ) grafted with blue and orange-red TADF units were synthesized via Suzuki polymerization and post “Click” reaction. In this strategy, the nonconjugated structure enhances the solubility of the polymers, while the combined approach of Suzuki polymerization and post “Click” reaction improves synthetic efficiency and enables precise emission color tuning. Meanwhile, the absorption spectrum of the orange-red TADF molecule shows a suitable overlap with the photoluminescence (PL) spectra of the polymer backbone and the blue TADF molecule, ensuring appropriate energy transfer in target polymers to form white light. The nondoped OLED based on PDFC-DT 97 -TB 3 achieved white electroluminescence with CIE coordinates of (0.33, 0.40), a maximum luminance ( L max ) of 242 cd m –2 and a maximum external quantum efficiency (EQE max ) of 0.26%. In contrast, a doped device using PDFC-DT 85 -TB 15 (10 wt %) in CBP achieved warm white emission with CIE coordinates of (0.35, 0.31), an L max of 1117 cd m –2 and an EQE max of 2.30%. These results demonstrate a promising strategy for the molecular design and synthesis of single-component TADF polymers toward efficient, solution-processable white OLEDs.