MIRDOT · Room-temperature mid-infrared sensors using colloidal quantum dots

Mid-infrared (MIR) sensors are pivotal in enabling a broad range of applications, including environmental monitoring, medical imaging, safety, and food analysis. The current sensing technologies within this spectral range (λ= 3-30 μm) rely on high-cost and complex fabrications of epitaxially grown semiconductors. These sensors are not monolithic to silicon photonics and require cryogenic operating temperatures, limiting their adoption to the market. Alternatively, colloidal quantum dots (CQD) offer unique properties for sensing MIR light, including low-cost production, ease of processing, and silicon CMOS compatibility. The MIRDOT project will develop room-temperature (RT), cost-effective, and high-performance MIR sensors using CQD. So far, CQD technology has revolutionized the optoelectronics industry, particularly through the development of advanced sensors such as PbS CQD near-infrared (NIR) image sensors. These sensors leverage interband transitions in CQD, limiting their sensitivity to the NIR region. Intraband transitions in CQD, however, enable access to MIR region. Previously, doped PbS and HgTe CQDs have been investigated for MIR detection through intraband absorption. Nevertheless, these detectors exhibit extremely poor sensitivity at RT due to structural constraints and background noise in the MIR. In this project, I propose to effectively address these limitations by upconverting MIR radiation to NIR emission, enabling reliable detection with standard silicon detectors at RT. In this project, I will develop CQD-MIR sensors by coupling doped PbS(Se) CQD with extreme plasmonic nanocavities under optical pumping. To integrate these sensors with CMOS technology, I will design and fabricate electrically-driven sensors. Finally, as proof-of-concept phase, I aim to develop MIR imaging and gas sensors that operate at RT using these CQD-MIR sensors. The MIRDOT project will extend CQD technology into new spectral regions, greatly advancing future technologies.