Near to Long-Wave Infrared Mercury Chalcogenide Nanocrystals from Liquid Mercury

International audience; HgTe nanocrystals are currently the most promising colloidal material for infrared detection, combining broadly tunable infrared absorption and photoconductive properties. Current synthesis leads to a limited amount of material and relies on a highly toxic water-soluble form of Hg. Here, we explore the possibility of using Hg thiolate as Hg source and demonstrate that the latter can be formed in situ from liquid Hg. The developed protocol allows large masses (7 g) and highly concentrated (100 g/L) synthesis, which is a step forward for the transfer of this material towards industry. The transport properties of the material have also been investigated and we observe a transition from p to n-type with size. We observe that the threshold of the p to n switch depends on the growth method which enables for a given size of nanocrystal the formation of p-n junction. This work has great potential to design infrared sensor with optimized charge dissociation.