| 摘要 |
<p>The present invention relates to a high efficiency organic light emitting display device capable of reducing material costs and reducing a driving voltage. The organic light emitting display device according to the present invention comprises first and second electrodes which are opposite to each other in a substrate; a first stack which has a hole injection layer, a first hole transportation layer, a second hole transportation layer, a first light emitting layer, and a first electron transportation layer sequentially laminated on the first electrode; a second stack which has a third hole transportation layer, a fourth hole transportation layer, a second light emitting layer, and a second electron transportation layer sequentially laminated between the first stack and the second electrode; and an electric charge generation layer which is formed between the first stack and the second stack to adjust electric charge balance between the stacks, wherein the second light emitting layer includes at least three hosts and one dopant, and one among at least three hosts has a highest occupied molecular orbital (HOMO) level and a lowest unoccupied molecular orbital (LUMO) level of the fourth hole transportation layer which are made of the same material. [Reference numerals] (224b) Fourth hole transportation layer; (226) Second light emitting layer; (228) Second electron transportation layer</p> |
