Abstract-TeraHertz HgTe nanocrystals: beyond confinement

Nicolas Goubet, Amardeep Jagtap, Clément Livache, Bertille Martinez, Hervé Portalès, Xiang Zhen Xu, Ricardo Lobo, Benoit Dubertret, and Emmanuel Lhuillier

https://pubs.acs.org/doi/10.1021/jacs.8b02039

We report the synthesis of nanocrystals with optical feature in the THz range. To do so, we develop a new synthetic procedure for the growth of HgTe, HgSe and HgS nanocrystals, with strong size tunability from 5 nm to 200 nm. This is used to tune the absorption of the nanocrystal all over the infrared range up to the teraHertz (from 2 µm to 65 µm for absorption peak and even 200 µm for cut-off wavelength). The interest for this procedure is not limited to large size since for small objects we demonstrate low aggregation, good shape control (i.e. spherical object) while using non-expansive and simple mercury halogenide precursors. By integrat-ing these nanocrystals into an electrolyte-gated transistor, we evi-dence a change of carrier density from p-doped to n-doped as the confinement is vanishing.