Organic light-emitting device and of preparing the same

An organic light emitting device, comprising:

• a substrate including a first subpixel region, a second subpixel region, and a third subpixel region;
• a plurality of first electrodes separately arranged in the first subpixel region, the second subpixel region, and the third subpixel region of the substrate;
• a second electrode arranged opposite the first electrode;
• a first emission layer (EML) arranged in the first subpixel region to emit light having a first color;
• a second emission layer arranged in the second subpixel region to emit light having a second color;
• a first layer arranged as a common layer with respect to the first subpixel region, the second subpixel region, and the third subpixel region;
• and
• at least one of a first auxiliary layer and a second auxiliary layer, wherein the first auxiliary layer is arranged between the first emission layer and the first layer, contacts a surface of the first layer and includes a first metallic compound to facilitate transportation of electric charges from the first electrode to the first emission layer, and wherein the second auxiliary layer is arranged between the second emission layer and the first layer, contacts the surface of the first layer and includes a second metallic compound to facilitate transportation of electric charges from the first electrode to the second emission layer.