Universal Display Corporation
ORGANIC ELECTROLUMINESCENT MATERIALS AND DEVICES

Abstract:

Provided are OLEDs and related electronic devices that utilize these OLED devices. The OLED includes an emissive region that includes a sensitizer and an acceptor, where the sensitizer has a lowest excitation energy state E.sub.T1, and is capable of harvesting triplet excitons; where the acceptor is capable of receiving energy from the sensitizer and functioning as a fluorescent emitter at room temperature; where the acceptor has a first moiety and a second moiety, the first moiety having a lowest singlet excitation energy state E.sub.S1.sup.A and a lowest triplet excitation energy state E.sub.T1.sup.A, and the second moiety having a lowest singlet excitation energy state E.sub.S1.sup.B and a lowest triplet excitation energy state E.sub.T1.sup.B; and where E.sub.S1.sup.A<E.sub.S1.sup.B, E.sub.T1.sup.A>E.sub.T1.sup.B, and E.sub.T1>E.sub.S1.sup.A.