Thermally Activated Delayed Fluorescence from Sn4+–Porphyrin Complexes and Their Application to Organic Light Emitting Diodes — A Novel Mechanism for Electroluminescence

Electroluminescence based on TADF, that is, thermally activated delayed fluorescence, is demonstrated in Sn4+–porphyrin complexes. On excitation by a short electrical pulse, prompt and delayed electroluminescence components were clearly observed. The delayed component was composed of both TADF and phosphorescence (see figure), and the TADF component significantly increased with increasing temperature.