Active polarimetric imager for detection of static and moving manufactured objects in natural environment

International audienc

HgTe Nanocrystals for SWIR Detection and their Integration up to Focal Plane Array

International audienceInfrared applications remain too often a niche market due to their prohibitive cost. Nanocrystals offer an interesting alternative to reach cost disruption especially in the shortwave infrared (SWIR, λ<1.7 µm) where material maturity is now high. Two families of materials are candidate for SWIR photoconduction: lead and mercury chalcogenides. Lead sulfide typically benefits from all the development made for wider bap gap such as the one made for solar cells, while HgTe takes advantage of development relative to mid wave infrared detector. Here we make a fair comparison of the two material detection properties in the SWIR and discuss the material stability. At such wavelengths, studies have been mostly focused on PbS rather than on HgTe, therefore we focus in the last part of the discussion on the effect of surface chemistry on the electronic spectrum of HgTe nanocrystals. We unveil that tuning the capping ligands is a viable strategy to adjust the material from p-type to ambipolar. Finally, HgTe nanocrystals are integrated into multi pixel devices to quantize spatial homogeneity and onto read out circuits to obtain fast and sensitive infrared laser beam profile