EP02.08.02 : Luminescent Copper(I) Carbene Complexes for Organic Light Emitting Diode Applications

4:00 PM–4:30 PM Apr 4, 2018 (America - Denver)

PCC North, 200 Level, Room 222 BC

Peter Djurovich1 Mark Thompson1

1, University of Southern California, Los Angeles, California, United States

Organic light emitting diodes (OLEDs) are being used in an increasing number of display and lighting applications due to their high efficiencies and vibrant colors. The high efficiency of these devices is enabled by the use of iridium(III) complexes as phosphorescent dopant emitters. One feature that favors these Ir phosphors as emissive dopants is their fast radiative rate constants (kr > 105 s-1) which help boost their luminescent efficiencies. We have investigated luminescent copper(I) complexes for a number of years as alternative phosphorescent dopants. These Cu(I) complexes typically have radiative rates that are an order of magnitude slower than values found for the Ir(III) complexes. The disparity in radiative rates is attributed to the relatively weak spin-orbit coupling induced by the light Cu atom. We have recently prepared a series of Cu(I) carbene complexes that have luminescent efficiencies and radiative rates comparable to those of the heavy Ir(III) complexes. We can tune the emission energies of these Cu(I) complexes from blue to red by varying the electron affinity of the carbene ligand, yet still retain the fast radiative rate constants. In this presentation, we will discuss the photophysical properties of these new phosphors and propose a mechanism for their unusually rapid radiative behavior.