"Soft" Liquid-Phase Adsorption for the Fabrication of Solution Processable Organic Material Films on Wettability-Patterned Surfaces

We discuss a "soft" liquid-phase adsorption (SLPA) technique for the fabrication of organic films on wettability-patterned templates by using methanol/hexane and toluene/water emulsions. The emulsions are stable for several hours at room temperature, and the diameters of the dispersed phase are estimated to be several micrometers using dynamic light scattering. The templates are fabricated by exposing self-assembled monolayers to an ultraviolet/ozone atmosphere through a shadow mask. Fluorescent dye and semiconductor polymer films are formed selectively on thee hydrophilic region of the substrates and the hydrophobic region of the self-assembled monolayer, respectively. The thickness is significantly larger than those of the films fabricated by conventional film-forming techniques such as spin-coating and dip-coating, respectively. These patterned films serve as photoluminescent films. These results demonstrate that the SLPA technique allows for the fabrication of organic films on wettability-patterned templates using solution-processable materials. This technique will find application to the fabrication of electronic and photonic devices with small material consumption and few film-forming processes.