6‐4: Highly Efficient Deep Blue Thermally Activated Delayed Fluorescent Emitter

We report a highly efficient and deep blue thermally activated delayed fluorescence material. This emitter exhibits extremely short delayed exciton lifetime (0.98 μs), narrow spectrum (46 nm FWHM), and high PLQY (~90 %). Fabricated device with this emitter shows high efficiency of 21.6% with extremely deep blue color coordinate of (0.14, 0.07).