Projekte
Kontakt
Silke Stauche
Koordinatorin für Masterzulassungen
Max-Planck-Ring 12
Werner-Bischoff-Bau
+49 3677 69-1841
Silke Stauche
Koordinatorin für Masterzulassungen
Max-Planck-Ring 12
Werner-Bischoff-Bau
+49 3677 69-1841
The scope of the research is to employ the cantilever tip of an atomic force microscope to carry out nanolithographic patterning with sub-20 nm resolution. By simply performing the experiments under ambient conditions, a molecular water film which is naturally adsorbed at sample surfaces allows a resistless tip-induced oxidation of metals (Mo, Cr) as well as semiconductors (Si, MoS2 etc.). In particular, atomically thin two-dimensional (2D) materials (MoS2, MoTe2, InSe etc.) are investigated since the tip-structuring of them enables a direct fabrication of nanoelectronics devices. Unless as for the conventionally used electron beam lithography, no high energetic electrons as well as no resist films are utilized. Due to this, an alteration of the investigated material through electron irradiation or resist residuals is avoided, which preserving its original physical properties.
Two-dimensional (2D) materials are a promising material class for the fabrication of various electronic devices. However, technologies are required to structure the materials without deterioration of their physical properties and to effectively integrate them into a functional device architecture. The research project focuses on the structuring and integration of 2D materials with emphasis to neuromorphic devices by using field-emission scanning probe lithography as a high-resolution direct writing process in combination with microtechnologies.
Based on the fact that electron beam induced deposition is a well-established nanofabrication technique capable of creating 3D micro- and nanostructures, we aim to explore in this regard scanning-probe-based strategies in combination with low-energy electrons. The overall principle is as well based on a decomposition of precursor gas molecules due to an interaction with electrons that are emitted from a nanoscale tip. The research focuses on system development on the one hand and on the other hand on fundamental research to elucidate the interrelationships between the individual system parameters. On this basis, it should be possible to produce 3D nanostructures in different material systems in the future.
Plasmonic near-field lithography is based on so-called plasmonic lenses, which require advanced nanofabrication processes for their realization. The research focuses therefore on the one hand on effective strategies to create plasmonic lenses and on the other hand on the realization of plasmonic nanolithography. In principle, structuring with a structural resolution below the theoretical limit of optical diffraction is feasible but require systems with nanometer-precision positioning capabilities at larger-scale, to harness the optical near field effectively.
UV-nanoimprint lithography is a capable nanotechnology for the parallel fabrication of micro- and nanostructures. In this project we are studying strategies to improve the imprinting process by adding metrological functionalities to the system that shall enable to perform nanoimprint lithography with high accuracy with respect to the lateral positioning and with respect to the stamp imprinting itself. The research includes system development, numerical simulations of the metrological setup and improvement of the nanoimprint stamps with respect to 3D structuring in macroscopic working areas.
Technical glasses and glass-ceramics allow to adapt their material properties for specific applications by adjusting their material composition and structure. The broad application fields of these special materials in microsystems requires suitable micro- and nanostructuring techniques. In this context, reactive ion etching is the preferred technology for a wide range of materials used in micro-electro-mechanical systems and micro-opto-electro-mechanical systems. One of our research foci is therefore the investigation of tailored and improved reactive ion etching processes with respect to complex silicate glass materials. The interactions with the plasma and the creation of suitable masking techniques are in this regard addressed as well as aspects of sustainability. A holistic approach is being pursued to pave the way for new types of glass-based systems and make previously underutilized glass materials (e.g. ultra-low expansion glasses and glass-ceramics) accessible in microsystems technology.
According to macroscopic electromagnetic force compensation scales with all their advantages like precise measurement in relatively large measuring ranges and even the traceability of masses to SI- units, a microscopical system with comparable advantages is subject of our research. Instead of electromagnetic forces for compensation, electrostatic force actuators and capacitive read-out strategies are employed and studied along with the micromechanical system design. The approach shall enable a measuring range from nanonewton to high micronewton or microgram to milligram with a resolution of single-digit nanonewton. Increasing the measuring range and resolution are further subjects of our ongoing research.
Electrohydrodynamic wetting manipulation plays a major role in modern microfluidic technologies which deals with the handling (including moving, mixing and separating) of fluids in the range of micro- to nanoliters. In research, we are therefore investigating various architectures of electrohydrodynamic systems and individual system components on the basis of numerical simulations and on the basis of experimental studies. Furthermore, droplet-based microfluidics (digital microfluidics) is addressed by various methods such as electrohydrodynamic actuation. Well-known applications for electrohydrodynamic wetting manipulation comprise inkjet technologies, microfluidic systems with emphasis to (bio)-chemical analytics as well as optics and display technology.
Spatial sensor technology plays a decisive role in the design and implementation of autonomous systems on land, at sea or in the air. Advanced sensor technology enables autonomous systems to reliably detect other objects in the immediate vicinity, assign speeds and distances and, in the event of danger to themselves or to neighboring objects (people, machines, vehicles), provide reaction recommendations to the system's control unit. Within this project, the limitations of existing systems will be overcome by a combination of a THz radar technology, innovative assembly and connection technology, MEMS and a novel material combination including silicon and LTCC (low-temperature co-fired ceramics) composite substrates.
In the pursuit of sustainable energy solutions, solar water splitting appears to be a promising approach for green (environmentally friendly) hydrogen production. Hematite (α-Fe2O3) has been intensively studied as a potential photoanode material due to its abundance, stability, and moderate band gap. In particular, its occurrence on earth and its environmental friendliness makes it to an attractive candidate for sustainable large-scale use. However, despite its promising properties, hematite still faces practical challenges such as poor charge carrier transport and fast recombination rates. Ongoing research efforts are therefore focused on overcoming its limitations and improving its photocatalytic performance to accentuating its potential for enabling the transition to a sustainable energy future. In addition, we study the surface band structure of hematite and other semiconducting materials under ambient conditions using Kelvin probe (KP) and ambient photoelectron spectroscopy (APS) as a key to understanding and improving the performance of semiconducting materials with respect to their applications, such as solar water splitting.