Patent ID: 8288187

Claim:
A method, comprising: a. providing a first electrode; b. providing a first solution having: an organic host material of a first organic layer; a first organic emitting material of the first organic layer; and a second organic emitting material of the first organic layer, wherein the first organic emitting material of the first organic layer is present in a concentration of 0.01-5wt %; and wherein the amount of the first organic emitting material of the first organic layer is measured to a variance of less than 5%; c. depositing the first organic layer over the first electrode via solution processing using the first solution, the first organic layer further comprising: i. the organic host material of the first organic layer; ii. the first organic emitting material of the first organic layer; iii. the second organic emitting material of the first organic layer; wherein the first and second organic emitting materials are co-doped in the organic host material; d. depositing a second organic layer over and in direct contact with the first organic layer, the second organic layer further comprising an organic emitting material of the second organic layer; and e. depositing a second electrode over the second organic layer.