Patent ID: 8754406

Claim:
An organic light emitting diode device (OLED), comprising: a substrate; a transparent electrode disposed on the substrate, the transparent electrode including a portion in a light emitting region; an emission layer disposed on the transparent electrode; a reflecting electrode disposed on the emission layer; a gate insulating layer interposed between the substrate and the transparent electrode, the gate insulating layer including: a first inorganic dielectric layer having a thickness of about 1000Å or less, the first inorganic dielectric layer being in contact with the portion of the transparent electrode in the light emitting region, and a second inorganic dielectric layer between the first inorganic dielectric layer and the substrate, the first and second inorganic dielectric layers having different refractive indices; and a plurality of buffer layers interposed between the substrate and the gate insulating layer and including a lower buffer layer, an intermediate buffer layer and an upper buffer layer, wherein the light emitting region is defined only in a region having the emission layer in direct contact with the transparent and reflecting electrodes, wherein the upper buffer layer, the intermediate buffer layer, and the lower buffer layer are increasingly thicker from the upper buffer layer to the lower buffer layer, and wherein the first and second inorganic dielectric layers are stacked between the upper buffer layer and the portion of the transparent electrode in the light emitting region.