Optical Micro-Patterning of Electronic Polymers for Device Applications

The largest need in organic electronic devices is a universal method to produce micro- to nano-scale features for devices from semiconducting polymers cheaply, and at scale. We recently developed a solution method to optically pattern conjugated polymers with sub-micrometer resolution. We examine the relationship between optical write intensity, write speed, and write wavelength on the resulting pattern fidelity. Finite element modeling reveals that nearly all polymer patterning occurs as a result of dissolution due to local optical heating. The dissolution rate as a function of light wavelength, intensity, and solvent quality can be quantitatively predicted with upper patterning rates of 5 m²/hr possible. We demonstrate the fabrication of polymer nanowires with cross section of 250x40 nm, which demonstrates the efficacy of this process for device fabrication. We also demonstrate optical patterning of conjugated polymers using a cleanroom photolithography instrument (Alvéole PRIMO). This is significant because it means that every organic electronics group can pattern with similar resolution using their own local commercial equipment. This patterning technology enables a whole new class of patterned conjugated polymer devices.