Synthesis and Characterization of Substituted 9,10-anthracene and The Applications in Blue Fluorescent Organic Light Emitting Diodes

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We have synthesized a family of anthracene derivatives with substitutions on the C-9 and C-10 positions. Anthracene derivatives could be activated by less energy and produced a higher S1 excited state. Therefore, we could get the higher frequency emission than we excite them directly. This phenomenon is also called triplet-triplet annihilation photon upconversion (TTA-UC). We utilize substitutions on anthracene in order to tune more appropriate energy level match between our light emitter layer (EML) and electron/hole transporting layers (ETL/HTL). By introducing these substituted groups, it can be facilitated the electron/hole-transporting ability of anthracene. Meanwhile, the higher molecular weight, the better thermal stabilities. We used cyclic voltammetry to characterize our target compound, their energy gap are between 2.8 eV to 3.0 eV approximately. From fluorescence and phosphorescence spectra, most of them could emit blue light by the TTA-UC process. We also make some PLED devices to analyze their photoelectric properties. Our compounds have higher electron mobility than DPA and possess great current efficiency. From OLED devices which are composed by vapor deposition, we could get the highest current efficiency of 1.69 cd/A at 6 V, the highest power efficiency of 0.92 lm/W at 5.5 V, the highest luminance of 3869 cd/m2 at 10 V, the largest EQE of 0.63% at 6 V. According to these outcome, we can make a conclusion that our compound have excellent potential to be the light emitting materials compared to DPA and ADN.