During the past decade, significant progress has been made in the field of resonant optics ranging from fundamental aspects to concrete applications. While several techniques have been introduced for the fabrication of highly defined metallic nanostructures, the synthesis of complex, free-standing three-dimensional (3D) structures is still an intriguing, but so far intractable, challenge. In this study, we demonstrate a 3D direct-write synthesis approach that addresses this challenge. Specifically, we succeeded in the direct-write fabrication of 3D nanoarchitectures via electron-stimulated reactions, which are applicable on virtually any material and surface morphology. By that, complex 3D nanostructures composed of highly compact, pure gold can be fabricated, which reveal strong plasmonic activity and pave the way for a new generation of 3D nanoplasmonic architectures that can be printed on-demand.

Background: Lytic polysaccharide monooxygenase (LPMO) has recently been discovered to depolymerize cellulose.Results: Dynamic imaging was applied to reveal the effects of LPMO and cellulase activity on solid cellulose surface.Conclusion: Critical features of surface morphology for LPMO synergy with cellulases are recognized.Significance: Direct insights into cellulose deconstruction by LPMO alone and in synergy with cellulases are obtained.

Focused electron beam induced deposition (FEBID) is an important synthesis method as it is an extremely flexible tool for fabricating functional (3D) structures with nanometer spatial resolution. However, FEBID has historically suffered from carbon impurities up to 90 at %, which significantly limits the intended functionalities. In this study we demonstrate that MeCpPtIVMe3 deposits can be fully purified by an electron-beam assisted approach using H2O vapor at room temperature, which eliminates sample and/or gas heating and complicated gas delivery systems, respectively. We demonstrate that local pressures of 10 Pa results in an electron-limited regime, thus enabling high purification rates of better than 5 min·nA–1·μm–2 (30 C·cm–2) for initially 150 nm thick deposits. Furthermore, TEM measurements suggest the purification process for the highly compact deposits occurs via a bottom-up process.

Focused electron beam induced deposition (FEBID) is one of the few techniques that enables direct-write synthesis of free-standing 3D nanostructures. While the fabrication of simple architectures such as vertical or curving nanowires has been achieved by simple trial and error, processing complex 3D structures is not tractable with this approach. In part, this is due to the dynamic interplay between electron-solid interactions and the transient spatial distribution of absorbed precursor molecules on the solid surface. Here, we demonstrate the ability to controllably deposit 3D lattice structures at the micro/nanoscale, which have received recent interest owing to superior mechanical and optical properties. A hybrid Monte Carlo-continuum simulation is briefly overviewed, and subsequently FEBID experiments and simulations are directly compared. Finally, a 3D computer-aided design (CAD) program is introduced, which generates the beam parameters necessary for FEBID by both simulation and experiment. Using this approach, we demonstrate the fabrication of various 3D lattice structures using Pt-, Au-, and W-based precursors.

Germanium halide perovskites are an attractive alternative to lead perovskites because of their well-suited optical properties for photovoltaic applications. However, the power conversion efficiencies of solar cells based on germanium perovskites remained below 0.2% so far, and also, the device stability is an issue. Herein, we show that modifying the chemical composition of the germanium perovskite, i.e., introducing bromide ions into the methylammonium germanium iodide perovskite, leads to a significant improvement of the solar cell performance along with a slight enhancement of the stability of the germanium perovskite. With substitution of 10% of the iodide with bromide, power conversion efficiencies up to 0.57% were obtained in MAGeI2.7Br0.3 based solar cells with a planar p–i–n architecture using PEDOT:PSS as hole and PC70BM as electron transport layer.

By the fabrication of periodically arranged nanomagnetic systems it is possible to engineer novel physical properties by realizing artificial lattice geometries that are not accessible via natural crystallization or chemical synthesis. This has been accomplished with great success in two dimensions in the fields of artificial spin ice and magnetic logic devices, to name just two. Although first proposals have been made to advance into three dimensions (3D), established nanofabrication pathways based on electron beam lithography have not been adapted to obtain free-form 3D nanostructures. Here we demonstrate the direct-write fabrication of freestanding ferromagnetic 3D nano-architectures. By employing micro-Hall sensing, we have determined the magnetic stray field generated by our free-form structures in an externally applied magnetic field and we have performed micromagnetic and macro-spin simulations to deduce the spatial magnetization profiles in the structures and analyze their switching behavior. Furthermore we show that the magnetic 3D elements can be combined with other 3D elements of different chemical composition and intrinsic material properties.

Recently, focused electron beam induced deposition has been employed to prepare functional magnetic nanostructures with potential in nanomagnetic logic and sensing applications by using homonuclear precursor gases like Fe(CO) 5 or Co 2 (CO) 8 . Here we show that an extension towards the fabrication of bi-metallic compounds is possible by using a single-source heteronuclear precursor gas. We have grown CoFe alloy magnetic nanostructures from the HFeCo 3 (CO) 12 metal carbonyl precursor. The compositional analysis indicate that the samples contain about 80 at% of metal and 10 at% of carbon and oxygen. Four-probe magnetotransport measurements are carried out on nanowires of various sizes down to a width of 50 nm, for which the room temperature resistivity of 43 µΩcm is found. Micro-Hall magnetometry reveals that 50 nm×250 nm nanobars of the material are ferromagnetic up to the highest measured temperature of 250 K. Finally, the TEM microstructural investigation shows that the deposits consist of a bcc Co-Fe phase mixed with a FeCo 2 O 4 spinel oxide phase with nanograins of about 5 nm diameter.2

Additive manufacturing of three-dimensional objects on the nanoscale is a very relevant topic but still a highly challenging task. Among the pool of nanofabrication techniques, focused electron beam induced deposition (FEBID) has recently developed from a trial-and-error laboratory method to a predictable 3D nanoprinting technology with unique advantages. This perspective article first introduces the basic principles of 3D-FEBID, followed by an overview of historical developments with a particular emphasis on the last three years. Here, we examine different aspects of 3D nanoprinting such as the instrumental setup, fundamental growth mechanisms, simulations, computer aided design software solutions, material properties, and application studies. For each aspect, the individual challenges and limitations are discussed. In addition, we share our outlook about possible solutions and studies currently under investigation. As a perspective, we also address the most urgent milestones of the future and speculate on applications ranging from optics to mechanics, magnetics, and electronics, all of them benefiting from the recently improved 3D FEBID synthesis technique.