Engineering GeSn Thin Films for Efficient MWIR Photodetectors

In recent years, infrared imaging technologies have expanded rapidly across applications such as environmental monitoring, thermal imaging, industrial inspection, and security. In particular, the mid-wave infrared (MWIR) spectral range is highly relevant for these applications due to its sensitivity to thermal emissions and molecular signatures. Today’s state-of-the-art MWIR detectors are typically based on III–V semiconductors such as InSb or HgCdTe, which offer excellent performance but are expensive and challenging to integrate with standard CMOS technology.

As a group-IV material system, germanium-tin (GeSn) has emerged as a promising alternative for infrared photonics. By incorporating tin into germanium, the bandgap can be engineered and extended into the MWIR range while maintaining compatibility with silicon-based fabrication platforms. This enables the development of cost-effective, scalable, and CMOS-compatible photodetectors. However, challenges remain in material growth, defect control, and device optimization to achieve high-performance MWIR detection.

The goal of this internship/master’s thesis project is to explore and develop GeSn-based thin-film absorbers for MWIR photodetection. The project will focus on the fabrication and characterization of GeSn layers with tailored compositions and thicknesses to achieve the desired spectral response. The candidate will work on device integration, including photodetector fabrication and performance evaluation.

After an initial training period, the selected candidate will work independently in a cleanroom and laboratory environment. The student will gain hands-on experience in semiconductor processing, as well as electrical and optical characterization techniques. Experimental feedback will be used to iteratively optimize material quality and device performance. The candidate will also be exposed to a broad range of structural and compositional analysis methods.

The work will be conducted within an international research team, providing continuous support and guidance. The ideal candidate is highly motivated, enjoys hands-on experimental work, and has strong problem-solving and data analysis skills. Given the international working environment, a good command of English is required.

For more information or application, please contact Isabel Pintor (Isabel.pintormonroy@imec.be)