Deep blue thermally activated delayed fluorescence emitters with a 9,9′-spirobifluorene-fused xanthone acceptor for efficient OLEDs

Efficient deep blue thermally activated delayed fluorescence emitters are developed based on a 9,9′-spirobifluorene-fused xanthone acceptor, which furnish deep blue electroluminescence and high external quantum efficiencies of up to 16%.