Hierarchical multicolor nano-pixel matrices formed by coordinating luminescent metal ions to a conjugated poly(4'-octyl-2',6'-bispyrazoyl pyridine) film via contact printing

Abstract

We introduce a cost-effective, yet feasible reactive printing approach namely, "coordination chemistry at the conjugated ligand polymer surface". By using a contact printing technique we selectively fabricated high resolution nano-pixel configurations consisting of red, blue and green (R,G,B) colors arranged in a hierarchical three-dimensional fashion. For this, we have synthesized a novel blue emitting conjugated ligand polymer, [poly(4'-octyl-2',6'-bispyrazoyl pyridine)] (∼ 7-8 KDa) having a tridentate ligand in its repeating unit which forms a thin film prone of binding metal ions. On top of this ligand polymer film, a layer of high-resolution cross-stripes (width ca. 800 nm) was printed comprised of Eu and Tb ions over a large area ∼ 100 × 100 μm2. The final woodpile-like assembly produced a new pixel group consisting of B; BG; BR; and BGR (White) colors. The area of the white emitting square is ca. 0.64 μm2. The patterned layers that make up the pixels are very thin and thus this new technique might find applications in flexible light emitting devices.