Organic light emitting device

A light emitting device including a first electrode, a light emitting portion on the first electrode, the light emitting portion including a plurality of light emitting units and at least one interconnecting layer between ones of the light emitting units that are adjacent to each other, and a second electrode on the light emitting portion. The at least one interconnecting layer includes a p-type charge generation layer doped with a p-type dopant and an n-type charge generation layer doped with an n-type dopant. At least one of the p-type charge generation layer and the n-type charge generation layer has a concentration gradient of the p-type dopant or the n-type dopant.