University of Freiburg appoints the new tenure track professor for sensors
Prof. Dr. Alwin Daus has been tenure-track professor for sensors at the Department of Microsystems Engineering (IMTEK) at the University of Freiburg since May 31, 2023. The electrical engineer previously worked at the RWTH Aachen University, Stanford University in the US and the ETH in Zurich, Switzerland. He is joined by his Emmy Noether group, which focuses on the growth of new two-dimensional semiconductors and their use in flexible field-effect transistors. “In future, I look forward to working with colleagues at various Freiburg institutes such as the IMTEK, the Institute for Sustainable Systems Engineering (INATECH), the Faculty of Medicine and the Fraunhofer Institutes,” says Daus.
Promising new materials
Daus’ research focuses on the use of thin-film semiconductor materials that can be incorporated into devices using low temperature processes. These include amorphous oxide semiconductors such as indium-gallium-zinc oxide or indium-tin oxide, which can be deposited at room temperature, and 2D transition metal dichalcogenides (TMDs), for which Daus has developed its own integration approach for flexible electronics. Integration with a low thermal budget is important because flexible plastic films can typically only withstand about 150 to 300 degrees Celsius before decomposing.
Similarly, there are increasing efforts in low-temperature processes for silicon integrated circuit (IC) technology. These enable the integration of functional components, such as non-volatile memories, at the back-end-of-line (BEOL), where the temperature must be limited to 400 to 450 degrees Celsius to prevent changes to the underlying silicon electronics.
A wide range of applications
The new semiconductor thin-film materials are promising for a variety of sensing applications such as temperature measurement, strain measurement and (bio)chemical measurement. Daus particularly wants to explore application scenarios that involve flexible substrates. Such flexible sensors could play an important role in various Internet-of-Things applications such as food packaging, inventory and environmental monitoring, electronic skin, and biomedical diagnostics.
In addition, the monolithic integration of new non-volatile memory devices into 3D ICs opens up new possibilities for the next generation of microprocessors, where such devices can be used as embedded memory or for in-memory computing. Part of Daus’ research involves developing resistive memory devices, called memristors, for use in brain-inspired (neuromorphic) computing, where each memristor performs the function of a synapse in analogy to the human brain.
Additional research
In addition to the work on sensors and memories, the research group will also focus on realising the technology of complementary transistors (p-type and n-type) with low power consumption on the hardware platforms of flexible electronics and BEOL 3D ICs to provide all the components that could be used in sensor systems. Another direction is to harness solar energy with 2D TMDs, a relatively new technology that enables ultra-thin absorber films due to their high optical absorption coefficients.