Patent ID: 8283856

Claim:
A light-emitting element comprising: a hole-transporting layer over a first electrode; a third layer fowled over the hole-transporting layer; a second layer formed over the third layer; a first layer formed over the second layer; and a second electrode formed over the second layer, wherein the first layer contains a first organic compound and a second organic compound, and wherein a ratio of the first organic compound in the first layer is greater than or equal to 0.1 wt % and less than 50 wt %, wherein the second layer contains a third organic compound and a fourth organic compound, and wherein a ratio of the third organic compound in the second layer is greater than or equal to 0.1 wt % and less than 50 wt %, and wherein the third layer contains the first organic compound and a fifth organic compound, and wherein a ratio of the first organic compound in the third layer is greater than or equal to 0.1 wt % and less than 50 wt %.