Patterning of polyfluorene based polymer light emitting diodes by reversal imprint lithography

The authors demonstrated the fabrication of patterned arrays of polymer light emitting diodes (PLEDs) with a polyfluorene based emissive layer using reversal imprint lithography. A stack of patterned metal and polymer films is transferred to a glass substrate in a single reversal imprint step. Two different techniques for coating the patterned Si mold are shown, one involving the spin coating of polymer layers directly onto the mold and one involving inking of the polymers onto the mold from a spin-coated PDMS inkpad. Using these techniques, PLED devices with a minimum feature sizes as small as 1 μm and luminescence starting at 3.5 V have been demonstrated.