Molecular fluorophores of type A–π–D–π–A (D=donor, A=acceptor) demonstrate solid‐state emission in the red to near‐infrared region with high efficiency. The emission color can be tuned through the substituents on the diarylamino and cyanophenyl moieties. The electroluminescence performance of the designed fluorophore confirms its potential as an emitter for use in organic light‐emitting devices.

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We synthesised 12,12-diisopropyl-7-methyl-12H-indololo[3,2-d]-naphtho [1,2-b][1]silole from 1-bromo-2-naphthol via four steps. The silylene-bridged 2-(2-naphthyl)indole exhibited intense blue photoluminescence in solution and in the solid state. For example, the fluorescence maximum of the powder appeared at 476 nm with a high quantum yield (F ¼ 0.70). The organic light-emitting device using the silylene-bridged indole as a light-emitting layer demonstrated a high current efficiency of 3.80 cd A À1 and a power efficiency of 3.64 lm W À1 at 10 mA cm À2 with excellent colour coordinates (0.152, 0.094), while the device fabricated with the blue-emissive indole as a dopant achieved even higher current and power efficiencies of 6.68 cd A À1 and 5.58 lm W À1 , respectively, at 10 mA cm À2 .