Laser-induced micro-patterning of organic semiconductor layers for use in organic light-emitting diode displays

Abstract

We proposed a novel method for micro-patterning organic semiconductor layers by using a laser irradiation system. The method was demonstrated with a precursor that changes solubility after thermal conversion. For micro-scale patterning, brief irradiation was crucial to prevent heat diffusion in the substrate. We found that preheating on a hot-plate is important for shortening the laser irradiation time necessary for the thermal conversion. The patterning resolution also depended on the kind of substrates as well as the laser exposure time. High-resolution line patterns with a width of 12 μm were successfully achieved on ITO substrates. Organic light-emitting diodes utilizing a patterned emitting layer, with line widths of 20 μm and spacing of 85 μm, were demonstrated.