US Patent 11437597 Organic electroluminescence device

An organic electroluminescence device includes a first electrode, a hole transport region disposed on the first electrode, a first emission layer disposed on the hole transport region and including a first light-emitting host and a first light-emitting dopant, a second emission layer disposed on the first emission layer and including a first electron transport material and a second light-emitting dopant, an electron transport region disposed on the second emission layer and including a second electron transport material, and a second electrode disposed on the electron transport region, wherein a triplet energy of the first light-emitting host (T1