| 摘要 |
It is an object of the present invention to provide a light-emitting element with high light emission efficiency. It is another object of the present invention to provide a light-emitting element with a long lifetime. A light-emitting device is provided, which includes a light-emitting layer, a first layer, and a second layer between first electrode and a second electrode, wherein the first layer is provided between the light-emitting layer and the first electrode, the second layer is provided between the light-emitting layer and the second electrode, the first layer is a layer for controlling the hole transport, the second layer is a layer for controlling the electron transport, and a light emission from the light-emitting layer is obtained when voltage is applied to the first electrode and the second electrode so that potential of the first electrode is higher than potential of the second electrode.
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