Applications of hot-exciton anthracene and imidazole derivatives in integrated organic blue-emitting diodes and ultraviolet photodetectors

We prepared four emitters using 1,2-diphenyl-1H-phenanthro [9,10-d]imidazole (PPI) as the chromophore unit, anthracene as the bridge and 1-naphthyl, 2-naphthyl, benzene and phenylcarbazole as peripheral groups, namely PPIAn1N, PPIAn2N, PPIAnp and PPIAnCz, and used them in integrated organic light-emitting diodes (OLEDs) and ultraviolet organic photodetectors(UVOPDs). All these four molecules exhibit hybridized local and charge transfer (HLCT) excited states with maximum emission peaks at similar to 433, 448, 446 and 450 nm in the film state, respectively. The non-doped OLED based on PPIAn2N exhibits excellent performances with a deep-blue emission at similar to 452 nm, CIE coordinates (Commission International de L'Eclairage) of (0.15, 0.11) and a maximum external quantum efficiency (EQE) of 7.3%. The integrated OLED-UVOPD based on PPIAn2N achieves a detectivity of 2.53 x 1012 Jones, a switching ratio of 4.57 x 104, a turn-on voltage of 3 V and a maximum power efficiency of 6.3 lm W-1. Our work highlights the application of integrated multifunctional devices in the deep-blue emission zone. Four hot-exciton blue emitters with different peripheral units were designed and applied in integrated organic light-emitting and ultraviolet photodetector devices. A detection rate of 2.53 x 1012 Jones and EQE of 7.3% were achieved.