Patent ID: 7274044

Claim:
A light emitting device comprising: a substrate; a first insulating layer provided over the substrate; a transistor provided over the first insulating layer; a second insulating layer having a first opening portion which is provided to expose the first insulating layer as well as covering the transistor; a first electrode provided to be overlapped with the first insulating layer in the first opening portion; a bank layer having a second opening portion which is provided to expose the first electrode as well as covering the second insulating layer; a light emitting layer provided to be overlapped with the first electrode in the second opening portion; and a second electrode provided to be overlapped with the light emitting layer in the second opening portion, wherein the first insulating layer prevents the diffusion of impurities and has a refractive index which is smaller than that of the first electrode and a refractive index which is larger than that of the substrate.