Directed Self-Assembly of Colloidal Quantum Dots Using Well-Ordered Nanoporous Templates for Three-Colored Nanopixel Light-Emitting Diodes

We demonstrate high-resolution light-emitting diodes based on well-defined nanoarrays of colloidal quantum dots (QDs) with different sizes in a large area using nanoporous templates. To fabricate the nanoporous templates, a thin film of asymmetric polystyrene-block-poly(2-vinylpyridine) copolymers (S2VPs) is spin-coated on a ZnO layer and solvent-annealed in a vapor of toluene to induce vertically oriented P2VP cylinders in a PS matrix. When immersed in ethanol, the surface of BCP thin films is reconstructed and well-ordered nanopores are generated over the whole surface. The nanopores are then directly utilized as templates for self-assembly of quantum dots during the spin-coating process. Consequently, the quantum dots of three primary colors are selectively deposited in nanopores and are used to fabricate a well-ordered array of nanometer-scale pixels that can be operated by applying the proper voltage for each color.