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US 9,666,822 B2Granted
Extended OLED operational lifetime through phosphorescent dopant profile management
AssigneeThe Regents of the University of Michigan
InventorsStephen R. Forrest, Yifan Zhang
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Abstract
This disclosure relates, at least in part, an organic light emitting device, which in some embodiments comprises an anode; a cathode; a first emissive layer disposed between the anode and the cathode, the first emissive layer comprising an electron transporting compound and a phosphorescent emissive dopant compound; and wherein the phosphorescent emissive dopant compound has a concentration gradient, in the emissive layer, which varies from the cathode side of the first emissive layer to the anode side of the emissive layer.
Claims16
An organic light emitting device comprising:
- an anode;
- a cathode;
- a first emissive layer disposed between the anode and the cathode, the first emissive layer comprising an electron transporting compound and a phosphorescent emissive dopant compound;
- wherein the phosphorescent emissive dopant compound is a hole transporter;
- and
- wherein the phosphorescent emissive dopant compound has a concentration gradient, in the emissive layer, wherein the concentration gradient varies according to a profile selected from the group consisting of:
- (i) linear towards the cathode side of the first emissive layer;
- (ii) non-linear towards the cathode side of the first emissive layer, wherein said non-linear profile corresponds to a polynomial function selected from the group consisting of a quadratic function, a cubic function, or a higher order function;
- and (iii) a step wise form.
6 more elements
Dependencies are inferred from the claim text.