41.4: Role of Triplet-Triplet Annihilation in Highly Efficient Fluorescent Devices

Studies of delayed electroluminescence in model OLEDs based on anthracene derivatives indicate that triplet-triplet annihilation contributes sign significantly to overall efficiency. Estimated contribution from annihilation depends primarily on anthracene host structure and operating current density, reaching as much as 20-30% in exemplary highly efficient devices at 20 mA/cm(2).