Disclosed is a light-emitting element including a first electrode, a first light-emitting layer, an ionic-liquid layer, a second light-emitting layer, and a second electrode. The first light-emitting layer is located over the first electrode and includes a first emissive polymer and an ionic liquid. The ionic-liquid layer is located over the first light-emitting layer and includes an ionic liquid. The second light-emitting layer is located over the ionic-liquid layer and includes a second emissive polymer and an ionic liquid. The second electrode is located over the second light-emitting layer. The light-emitting element may further include a first substrate under the first electrode, a second substrate over the second electrode, and a sealing layer located between the first substrate and the second substrate and surrounding the first electrode.