This working group’s profile includes the development, production, and characterization of semiconductor layers and nanostructures, in particular those based on silicon and transparent conductible oxides for novel components such as optical sensors and solar cells on very different carrier materials.
Their goal is the development and application of scalable technologies for the production and modification of novel semiconductor layers and layer systems with nanostructured surfaces for a wide range of applications, in particular in medical and environmental technology. Their work is based on a wide spectrum of coating methods such as CVD, PECVD, electron beam evaporation, sputtering techniques, ALD, and diving applications for silicon ink. Combined with laser methods and wet-chemical etching methods, layer structures and systems and layer surfaces with special properties for sensor applications and energy production and storage can be obtained.
Research topics include multi-crystalline silicon thin-film solar cells based on laser-crystalline layers with nanostructured surfaces, PV chips for the detection of bioreactions, environmental parameters, and safety applications, novel silicon nanowire-based optical sensors with a high spatial resolution for next-generation camera systems, high-power battery electrodes based on etched nanowires in silicon layers and smart textiles with energy-harvesting functions.
The goal of the research of multi-crystalline silicon thin-film solar cells is to produce high-quality silicon material on inexpensive substrates like glass (which, due to the required processing temperature of more than 1400°C, can only be achieved via a laser melt process) and then prepare solar cells with efficiency rates that are comparable to the multi-crystalline silicon wafer cells dominating the market. The nanostructures etched into the surface provide support and facilitate effective light absorption.
When used as electrodes in Li ion batteries in the future, these types of layers, which are applied to metal foil, can also lead to an increase in the charge capacity that is one order of magnitude larger than graphite-based electrodes. Arrays made of silicon nanowires with functional surfaces via applied highly-doped semiconductor layers can also be used as high-power imaging sensors (for light, X-ray, and gamma radiation) or particle detectors depending on the design. Targeted application areas include basic research, high-energy physics, the life sciences, and next-generation cameras.
The research performed on PV chips based on a-Si:H layer systems centers around the inexpensive energy-independent detection, for example, of biomolecular interactions and harmful environmental gas emissions. Here, changes in the transparency of the reaction layers and thus changes in the illumination of the PV layers can be used in detection.
In the development of smart textiles, the focus is on coating with energy-producing photovoltaic or thermoelectric layers, partially with new functions for applications in the area of safety technology.