Organic light emitting devices

1. A white organic light emitting device, comprising:

an anode;

a cathode; and

a light emitting region comprising a layer of blue electroluminescent material, the layer consisting essentially of one or more fluorescent materials that emit blue light and doped with one or more phosphorescent materials that emit red light, and with one or more phosphorescent materials that emit green light;

wherein the concentration of the one or more fluorescent materials is 2% by volume;

wherein the phosphorescent materials that emit red light allow the partial retention of blue emission from the fluorescent materials; and

wherein the phosphorescent materials that emit green light allow the partial retention of blue emission from the fluorescent materials.

2. The device of claim 1 , wherein the phosphorescent materials that emit red light, or the phosphorescent materials that emit green light is doped to a concentration of 0.01% to 25% by volume.

3. The device of claim 1 , wherein the phosphorescent materials that emit red light is:

and

wherein the phosphorescent materials that emit green light is:

4. A white organic light emitting device, comprising:

an anode;

a cathode; and

a light emitting region comprising a layer of blue electroluminescent material, the layer consisting essentially of one or more fluorescent materials that emit blue light doped with one or more phosphorescent materials that emit yellow light;

wherein the concentration of the one or more fluorescent materials is 2% by volume; and

wherein the phosphorescent materials that emit yellow light allow the partial retention of blue emission from the fluorescent materials.

5. The device of claim 4 , wherein the phosphorescent materials that emit yellow light is doped to a concentration of 0.01% to 25% by volume.

6. The device of claim 4 , wherein the phosphorescent materials that emit yellow light is: