Effect of Laser-Induced Direct Micropatterning on Polymer Optoelectronic Devices.

Solution-processed polymer devices have been studied as a low-cost alternative to the conventional vacuum-processed organic devices. However, forming a specific pattern on polymer semiconductor films without costly lithography is still challenging. Herein, we report a low-cost direct patterning method for polymer optoelectronic devices, which can successfully engrave designated patterns on the polymer semiconductor layer regardless of its size and even after device encapsulation. Irradiation of a 100 ns pulse laser forms high-resolution patterns on devices such as polymer light-emitting diodes and polymer memory devices. The biggest advantage of the proposed patterning method is that it does not produce any physical damage in the device, such as leakage current or degraded light-emitting efficiency. Analysis confirms that the laser-induced heat alters the solid or crystal structure of the polymer semiconducting layers so that the designated areas of the polymer devices can be selectively and deliberately deactivated. We demonstrate the usability of the developed laser-induced direct-patterning method on the polymer devices by engraving a digital image onto "ON-state" light-emitting devices and by generating multiple states onto a 4 × 4 matrix polymer nonvolatile memory.