Highly efficient dual anthracene core derivatives through optimizing side groups for blue emission. (November 2017) - Lee, Hayoon
Abstract: TP-AA-TPB, TP-AA-TPB, TPB-AA-TPB, TP-AA-DPA, TP-AA-TPA, and TPB-AA-TPA were synthesized using a 9, 9'-bianthracene (AA core). Through a systematic side group change, we optimized the dual-core chromophore system and investigated the relationship between the core and the side groups. The ultraviolet-visible (UV-Vis) absorption of the six materials showed an intrinsic absorption peaks of anthracene in the range of 360 nm–410 nm and photoluminescence (PL) emission in the blue region. The minimum decomposition temperatures (Td ) was 425 °C, the minimum melting temperatures (Tm ) was 335 °C, and the minimum glass transition temperatures (Tg ) was 176 °C. We achieved excellent overall electroluminescence (EL) efficiency in non-doped OLED devices using the six synthesized materials as emitting layer (EML). TPB-AA-TPA synthesized through size and polarity optimization of the side groups on the AA core had a current efficiency of 8.97 cd/A, power efficiency of 4.43 lm/W, external quantum efficiency (EQE) of 6.37%, and Commission Internationale de L'Eclairage coordinates (CIE) of (0.14, 0.19). TPB-AA-TPA also maintained blue emission and realized the highest EL efficiency among the six synthesized materials. Graphical abstract: Highlights: Six materials were synthesized by systematically changing the side groups on the AA core. Type (B) showed higher EL efficiency than Type (A) due to the electron donating effect of side group. TPB-AA-TPA(6) with a bulky size group and aromatic amine side group, showed the highest EL efficiency.