Using 4,9-dibromopyrene as a key intermediate, two new fused-core compounds, TP-PFF and TP-PFC-TP, were synthesized. These compounds not only exhibited excellent thermal stability but also yielded superior electroluminescence (EL) devices with a lower turn-on voltage, over 50% greater efficiency, and over 3 times longer lifetime than did a similar compound lacking a fused core. This new core-forming method can be applied in various applications with many different core groups.