Nanocristaux colloïdaux pour l'optoélectronique du visible à l'infrarouge à ondes courtes

Colloidal semiconductor nanocrystals offer a compelling platform for optoelectronics due to their size-dependent bandgap, low-cost synthesis, and solution-processability. These properties have enabled their application in LEDs, photodetectors, and solar cells, with commercial success in display and imaging technologies. This thesis investigates their potential across the visible to short-wave infrared (SWIR) spectrum, focusing on light modulation, electronic doping, and thermal stability for advanced optoelectronic devices. The research begins by demonstrating efficient electro-optic modulation of photoluminescence in CdSe nanoplatelets under a CMOS-compatible reverse bias, and the underlying modulation mechanism is investigated. Extending into the SWIR range, the focus shifts to the nanocrystal properties relevant to SWIR imaging applications. This work presents a comprehensive study of energy level alignment in PbS nanocrystals, examining the effects of particle size, surface ligands, and remote doping. In the case of HgTe nanocrystals, a focal plane imager is fabricated, revealing performance degradation due to Joule heating-induced particle coalescence. To address this, HgTe/CdS core/shell nanocrystals with improved thermal and chemical stability are developed. Their integration into imagers achieves low dark current, long-term operational stability, and enhanced external quantum efficiency, representing a significant advancement in HgTe-based SWIR imaging technology.