CPC H10K 50/16 (2023.02) [H10K 71/164 (2023.02); H05B 33/22 (2013.01); H10K 50/155 (2023.02); H10K 85/324 (2023.02); H10K 85/6572 (2023.02); H10K 2101/30 (2023.02)] | 20 Claims |
1. An organic electroluminescent device comprising:
an anode;
an electron transport layer; and
a cathode,
wherein a material of the electron transport layer comprises a mixture of a first electron transport material and a second electron transport material,
wherein a lowest unoccupied molecular orbital energy level of the first electron transport material is higher than that of the second electron transport material;
wherein a ratio of the first electron transport material to the second electron transport material first decreases and then increases in a direction from the cathode to the anode; and
wherein a ratio of the first electron transport material to the second electron transport material at a third interface in the electron transport layer is lowest.
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