From Mesoscopic to Nanoscopic Surface Structures: Lithography with Colloid Monolayers

Abstract

Colloid monolayer lithography is briefly reviewed and demonstrated to be a powerful alternative technique for the nanostructuring of surfaces. The Figure shows a colloid monolayer viewed through a TEM grid used to transport the monolayer to the desired substrate. The monolayer and grid together form a lithographic mask that can later be removed to leave, for example, a pattern of deposited gold dots.

Non‐Close‐Packed Crystals from Self‐Assembled Polystyrene Spheres by Isotropic Plasma Etching: Adding Flexibility to Colloid Lithography

“…[17] In its standard implementation, mono-or bilayers of spherical colloids, mostly polystyrene (PS), are directly used as evaporation or sputter masks resulting in almost triangular nanostructures exhibiting six-fold symmetry reflecting the close-packed structure of the spherical colloids forming the mask. [18][19][20][21] Since the size of the deposited triangles is related to the diameter of the colloidal particles, applying smaller spheres seems to be a natural route towards further reduced length scales. It turns out, however, that it becomes increasingly difficult to conserve the hexagonal order of close packing for nanospheres with diameters below 100 nm.…”

Restricted meniscus convective self-assembly

“…They can be fabricated through a number of different methods [15][16][17], including sedimentation [18][19][20][21], slow evaporation [2,22], spin or drop casting [23][24][25][26], microfluidic packing [6,27], electrostatic assembly [28], covalent attachment [29], or Langmuir-Blodgett methods [30]. In applications where the goal is to produce thin films, containing three layers of colloids or less, and where poly-crystalline ordering of the lattice is sufficient, convective assembly, also known as evaporation-induced self-assembly [31][32][33][34][35][36], is probably the fastest and most convenient technique to implement.…”

UV‐Light‐Driven Immobilization of Surface‐Functionalized Oxide Nanocrystals onto Silicon

“…Unexpectedly interesting behavior was observed for TiO 2 NRs, which can be efficiently anchored to silicon by oleic acid capping ligands likely via a radical photocatalytic mechanism. Currently, studies are in progress to assess the performances of the obtained oxide-Si and metal oxide-Si nanocomposite films in metal-enhanced photocatalytic systems, [43b] charge storing, [43c,d] and magnetic [1][2][3][4][5][6][7][8][9][10]32] solid-state devices.…”

“…[1][2][3][4][5][6][7][8] Such interest is justified by the expectation that the controlled assembly of NCs with individually relevant size-, shape-, and composition-dependent properties will open access to unusual collective phenomena relevant to novel technological applications. [9,10] The chemically directed assembly of NCs onto substrates requires the introduction of functionalities onto the NC surface in order to improve the processability and/or tune the reactivity of the particles without altering their original structural and chemical-physical properties.…”