US Patent 11183670 Organic light emitting diode with split emissive layer

An organic light emitting diode (OLED) device includes an emissive layer having a first sublayer with a first emitter as a dopant, a second sublayer with a second emitter as a dopant, and a third sublayer with a third emitter as a dopant. The second sublayer is between the first sublayer and the third sublayer. A concentration of the first emitter in the first sublayer exceeds a concentration of the third emitter in the third sublayer, and the concentration of the third emitter in the third sublayer exceeds a concentration of the second emitter in the second sublayer.