Direct patterning of tris-(8-hydroxyquinoline)-aluminum (III) thin film at submicron scale by modified micro-transfer molding

Tris-(8-hydroxyquinoline)-aluminum (III) (AlQ3) is one of the most widely used materials for its high luminescence efficiency in organic light-emitting devices. We propose the fabrication at submicron resolution of a patterned thin film of AlQ3 on a SiO/Si surface by modified micro-transfer molding. The process is made in one step and takes a few minutes. The film is formed during the transfer process, it is continuous and does not exhibit signs of stress or rupture. After applying a drop of AlQ3 solution to the surface of the mold, we placed it on the surface of the sample without removing the excess ink. The film is formed during the printing process. In this manner, it is possible to obtain a patterned homogeneous film with nanometer-size features in a single step, with no change in its adhesion and mechanical properties. Since there is not any specificity between the mold and AlQ3, we suggest that our procedure may be of general use for conjugated materials.