The international conference MATERIALSMEET2025 will take place in Budapest from 10th-12th April 2025. This interdisciplinary platform for materials and nanosciences brings together scientists, industry, educational experts and users to discuss and initiate joint projects.
At the conference, Dr. Tobehn-Steinhäuser from the CiS Research Institute will discuss the topic “Semiconductor devices at cryogenic temperatures” for the application of hydrogen as an invited speaker on 11th April 2025. Temperatures of -274 °C are required for the transportation and storage of hydrogen and must be monitored using robust, cost-effective and precise sensors. In this temperature range, the freezing-out effect occurs in doped semiconductors. This effect refers to the decrease in charge carriers in the conduction band, which switch to the valence band as the temperature drops. Extensive Hall measurements on samples with different doping levels showed that this effect already occurs at room temperature. In addition, the measurements indicate that below 40 K other conduction mechanisms become effective than those described in the usual theories of semiconductor physics.
The data generated is used to adapt the mobility models stored in common simulation models, which are valid up to a minimum of 70 K (Klaassen model). This range was previously sufficient for industrial applications. The investigations were based on our own chip designs. All components (Hall structures, diodes, semiconductor resistors, JFETs) were manufactured in-house.
The research and development work described was funded in research projects by the Federal Ministry for Economic Affairs and Climate Action (BMWK):
„CryoSense2R“ – Funding code: 49MF230124
„Freezing out“ – Funding code: 49VF190056
„TeLa“ – Funding code: 49VF170014
