DFG Project: Thermoelectric properties of SiGeSn microdevices
Thermoelectrics (TE) holds great potential for the development of green information technology, as it can provide energy harvesting and thermal control with direct heat-electricity conversion. However, current materials are difficult to integrate in large-scale production, or their performance is too low around room temperature. To this aim, the use of tin (Sn)-based alloys with Si and Ge is of great interest, as it can bring CMOS-integrated TE with qualitatively better performance with respect to SiGe. SiGeSn material system has been in the spotlight recently due to its application in lasers thanks to possible direct bandgap, and these developments are supported by epitaxial growth techniques for high-quality materials. Its TE application is nonetheless little explored and confined to amorphous and polycrystalline materials, that may not be suitable for optoelectronic CMOS devices.
Our recent results have shown that thermal conductivity in high-quality GeSn epilayers can be as low as in amorphous GeSn, a desired feature for TE performance. Therefore, we propose an investigation of the SiGeSn alloys for its use in thermoelectric devices. The results from this research will build a relevant cluster of knowledge and expertise in a field crucial in the development of energy materials which are environmentally friendly and resilient to geo-political crises.
