US Patent 7819716 Organic electroluminescent element and the manufacturing method

A manufacturing method of an organic electroluminescent element is provided. The method includes forming an insulator layer between pattern-formed pixel electrodes on a substrate, and forming a hole transport layer by printing hole transport ink, having a hole transport material dissolved in a solvent, on the pixel electrodes between the insulator layers by relief printing, wherein the hole transport ink includes 3,4-polyethylen dihydroxy thiophen (PEDOT), and monohydric alcohol and dihydric alcohol as solvents.