Thin Film Photodetectors for Extended SWIR Spectral Sensing

Sensing and imaging beyond the visible spectrum are essential for accessing information related to material composition, chemical content, and biological structure that cannot be revealed by conventional cameras. In particular, the short‑wave infrared (SWIR) region has become increasingly important for applications such as industrial inspection, machine vision, agriculture, medical diagnostics, and environmental monitoring. Extending detection further into the extended SWIR (eSWIR) range (1.7-2.5 µm) provides additional value by capturing strong molecular absorption features, enabling improved material discrimination and spectrally rich sensing.

Current SWIR image sensors rely mainly on epitaxial III–V technologies such as InGaAs. These technologies are characterized by high cost and challenges in scaling to high resolution. Additionally, eSWIR photodetector suffer from high dark current due to the lattice mismatch between InGaAs and InP substrate.

At imec, we have a strong track record in the development of thin‑film photodetectors and image sensors based on colloidal quantum dots, aiming to enable more affordable, scalable, and higher‑resolution SWIR imaging solutions. This effort addresses multiple challenges in parallel, including photodetector sensitivity, integration on readout ICs (ROICs), ROIC design and characterization, and fabrication upscaling. While significant progress has been made for SWIR, eSWIR photodetectors and image sensors have not yet been explored within this platform.

The goal of this internship is to investigate eSWIR photodetectors based on colloidal quantum dots and to explore their integration with imec’s proprietary optical filter technology to enable compact spectral sensing. The student will be involved in hands‑on device fabrication in the cleanroom, as well as electrical and optical characterization of the photodetectors and filter‑integrated structures. After initial training, the student is expected to contribute independently to this exploratory experimental research.

Responsible scientist(s): for further information or application, please contact Vladimir Pejovic (Vladimir.Pejovic@imec.be).