For the last decades, the Silicon-based semiconductor industry has been dominated by data processing using PCs, notebooks and workstations. These applications have shaped the evolution of integrated circuits. Now, the rise of other application areas such as the Internet of Things and Industry 4.0 constitutes the driving force behind a diversification of integrated functionality on semiconductor chips: Sensors and optoelectronic components are becoming more and more relevant. For these applications, however, the semiconductor material Silicon reaches its physical limits: Silicon as an indirect semiconductor is of limited use in optoelectronic components, for example. The development of many new application areas with direct societal relevance (low power mobile technologies, ultra-fast data transfer, life science applications, cognitive systems) will only be possible if an integration of diverse materials (such as other semiconductors or oxides) on the mature Silicon platform can be realized. This enables on-chip integration and cost-effective manufacturing. To this end, the materials themselves do not only have to be synthesized and characterized on Si, they also have to be integrated into device processing on Si wafers.
Since August 2018 we have been researching the development, fabrication and characterization of nano- and optoelectronic devices based on the semiconductors Silicon (Si), Germanium (Ge) and Tin (Sn). Our main topics are
- Materials research: Our research on group-IV semiconductor alloys is focused on the fabrication and characterization of semiconductor nanostructures such as quantum wells and quantum islands:
- Optoelectronic devices: The semiconductor alloy GeSn is a direct semiconductor at high Sn content (in contrast to Ge) and thus ideally suited for application in optoelectronic components. Our research on the combination of metallic nanostructures (plasmonics) with optoelectronic devices (photonics) has potential applications that range from on-chip biosensing to quantum information processing:
- Spintronics: Using not only electron charge but also electron spin for information processing can significantly increase the energy efficiency of devices. However, the technological obstacles to the realization of such devices are large. Our research is mainly concerned with the fabrication of ferromagnetic electrodes based on alloys containing Mn and their use in spintronic devices: