| 초록 |
Recently, thermally activated delayed fluorescence (TADF) has been used to produce high-performance OLEDs based on emitters. However, only a few studies on solution-processed OLEDs utilizing highly soluble TADF emitters have been reported so far. In this study, π-conjugated TADF polymers were designed and synthesized using benzophenone-based donor–acceptor frameworks. These TADF polymers showed relatively small ∆EST values, which enabled efficient exciton-harvesting via spin up-conversion from non-radiative T1 states to radiative S1 states. OLEDs using TADF polymer as emitters were fabricated by solution processes, and produced green and yellow emissions with maximum external quantum efficiency values of 9.3±0.9% which greatly exceeded the theoretical limit for conventional fluorescent OLEDs. We believe that these results can provide a molecular design strategy for continued exploration of efficient TADF polymer emitters and the development of solution-processed TADF-OLEDs. |
