US Patent 9899636 Photolithographic patterning of organic electronic devices

A method of making an OLED device includes providing a first undercut lift-off structure over the device substrate having a first array of bottom electrodes. Next, one or more first organic EL medium layers including at least a first light-emitting layer are deposited over the first undercut lift-off structure and over the first array of bottom electrodes. The first undercut lift-off structure and overlying first organic EL medium layer(s) are removed by treatment with a first lift-off agent comprising a fluorinated solvent to form a first intermediate structure. The process is repeated using a second undercut lift-off structure to deposit one or more second organic EL medium layers over a second array of bottom electrodes. After removal of the second undercut lift-off structure, a common top electrode is provided in electrical contact with the first and second organic EL medium layers.