Enhanced Strain in Functional Nanoporous Gold with a Dual Microscopic Length Scale Structure

We have synthesized nanoporous Au with a dual microscopic length scale by exploiting the crystal structure of the alloy precursor. The synthesized mesoscopic material is characterized by stacked Au layers of submicrometer thickness. In addition, each layer displays nanoporosity through the entire bulk. It is shown that the thickness of these layers can be tailored <i>via</i> the grain size of the alloy precursor. The two-length-scale structure enhances the functional properties of nanoporous gold, leading to charge-induced strains of amplitude up to 6%, which are roughly 2 orders of magnitude larger than in nanoporous Au with the standard one-length-scale porous morphology. A model is presented to describe these phenomena

Molecule-by-Molecule Writing Using a Focused Electron Beam

The resolution of lithography techniques needs to be extended beyond their current limits to continue the trend of miniaturization and enable new applications. But what is the ultimate spatial resolution? It is known that single atoms can be imaged with a highly focused electron beam. Can single atoms also be written with an electron beam? We verify this with focused electron-beam-induced deposition (FEBID), a direct-write technique that has the current record for the smallest feature written by (electron) optical lithography. We show that the deposition of an organometallic precursor on graphene can be followed molecule-by-molecule with FEBID. The results show that mechanisms that are inherent to the process inhibit a further increase in control over the process. Hence, our results present the resolution limit of (electron) optical lithography techniques. The writing of isolated, subnanometer features with nanometer precision can be used, for instance, for the local modification of graphene and for catalysis

Molecule-by-Molecule Writing Using a Focused Electron Beam

The resolution of lithography techniques needs to be extended beyond their current limits to continue the trend of miniaturization and enable new applications. But what is the ultimate spatial resolution? It is known that single atoms can be imaged with a highly focused electron beam. Can single atoms also be written with an electron beam? We verify this with focused electron-beam-induced deposition (FEBID), a direct-write technique that has the current record for the smallest feature written by (electron) optical lithography. We show that the deposition of an organometallic precursor on graphene can be followed molecule-by-molecule with FEBID. The results show that mechanisms that are inherent to the process inhibit a further increase in control over the process. Hence, our results present the resolution limit of (electron) optical lithography techniques. The writing of isolated, subnanometer features with nanometer precision can be used, for instance, for the local modification of graphene and for catalysis

Molecule-by-Molecule Writing Using a Focused Electron Beam

The resolution of lithography techniques needs to be extended beyond their current limits to continue the trend of miniaturization and enable new applications. But what is the ultimate spatial resolution? It is known that single atoms can be imaged with a highly focused electron beam. Can single atoms also be written with an electron beam? We verify this with focused electron-beam-induced deposition (FEBID), a direct-write technique that has the current record for the smallest feature written by (electron) optical lithography. We show that the deposition of an organometallic precursor on graphene can be followed molecule-by-molecule with FEBID. The results show that mechanisms that are inherent to the process inhibit a further increase in control over the process. Hence, our results present the resolution limit of (electron) optical lithography techniques. The writing of isolated, subnanometer features with nanometer precision can be used, for instance, for the local modification of graphene and for catalysis

Selective Functionalization of Tailored Nanostructures

The controlled positioning of nanostructures with active molecular components is of importance throughout nanoscience and nanotechnology. We present a novel three-step method to produce nanostructures that are selectively decorated with functional molecules. We use fluorophores and nanoparticles to functionalize SiO features with defined shapes and with sizes ranging from micrometers to 25 nm. The method is called MACE-ID: molecular assembly controlled by electron-beam-induced deposition. In the first step, SiO nanostructures are written with focused electron-beam-induced deposition, a direct-writing technique. In the second step, the deposits are selectively silanized. In the final step, the silanes are functionalized with fluorescent dyes, polystyrene spheres, or gold nanoparticles. This recipe gives exciting new possibilities for combining the highly accurate control of top-down patterning (e-beam direct writing) with the rich variety of the bottom-up approach (self-assembly), leading to active or responsive surfaces. An important advantage of MACE-ID is that it can be used on substrates that already contain complex features, such as plasmonic structures, nanoantennas, and cavities