Microfabrication of an electroluminescent polymer light emitting diode pixel array

Abstract

We describe a method to microfabricate a light emitting diode array with pixels based on conjugated electroluminescent polymers sandwiched between appropriate electrodes. This method, based on direct photoablation with the 193 nm emission of an excimer laser, maintains the properties of these unique polymers. The technique as described here has already achieved an array of 20 μm×20 μm pixels with enhanced electroluminescence (EL) from these pixels and possible spectral tuning of the EL by the application of varying external field. This method can be extended to achieve nanometer dimensionalities using near-field nanolithography.

Enhanced Luminance of Blue Light‐Emitting Polymers by Blending with Hole‐Transporting Materials

“…[1,2] For molecular electronics, transparent conductive oxides (TCOs) [3] with an atomically flat and stepped surface are considered to be a promising electrode material to fully utilize both electronic and optical functions of organic molecules, because epitaxial layers grown laterally on the flat surface are suitable for the fabrication of planar devices such as organic light-emitting diodes (OLEDs) and organic thin-film transistors (OTFTs). Furthermore, atomically flat and stepped surfaces of the substrate allow supramolecular structures [4,5] to be fabricated by stacking two-dimensional (2D) laterally grown epitaxial layers.…”

“…The use of conventional photolithography is difficult to apply to the fabrication of full-color PLEDs because many organic thin films are susceptible to damage during solvent exposure. Thus, several alternative patterning methods have been demonstrated: the use of excimer laser ablation, [1] ink-jet printing, [2±4] and micropatterning by cold welding. [5] A more recent method for patterning PLEDs is laser-induced thermal imaging (LITI), a process developed by 3M (St. Paul, MN).…”

Advanced syntheses and microfabrications of conjugated polymers, C60-containing polymers and carbon nanotubes for optoelectronic applications

“…Upon removal of the mask, colored polymer patterns were obtained, which emitted electroluminescently in a patterned fashion [302,303]. An LED array consisting of micro-meter-sized emitting pixels has been recently constructed [565] from a PPV copolymer (i.e. poly(1,4-phenylenevinylene-co-2,6-pyridylenevinylene)) [566] through a selective laser ablation process [388].…”

Patterning π-Conjugated Polymers

“…[50] Deposition of an Al layer and subsequent selective ablation of the Al to yield lines of similar dimension but orthogonal to the polymer lines afforded 20 20 lm structures that displayed electroluminescence (EL). Although, the pixels of the structure were not individually addressable, it was demonstrated that micrometer-sized pixels can be formed in a simple and parallel fashion.…”