Influence of the substrate hydrophilicity on the grid assisted deposition of tris-(8-hydroxyquinolinato) aluminum(III) thin films

The influence of the substrate wetting properties on the grid assisted deposition of tris-(8-hydroxyquinolinato)aluminum(III) (Alq₃) onto Si/SiO_x surfaces was investigated. Different degrees of hydrophilicity/hydrophobicity on the Si/SiO_x were obtained by changing the surface chemical functionalities with wet treatments. We observed that the deposited Alq₃ films can be spatially controlled and assembled either into continuous grid-like stripes or ordered dots depending upon the wetting properties of the substrate.