Terahertz HgTe Nanocrystals: Beyond Confinement

Nicolas Goubet (1, 2) , Amardeep Jagtap (1) , Clément Livache (1) , Bertille Martinez (1) , Hervé Portalès (3) , Xiang Zhen Xu (2) , Ricardo Lobo (2) , Benoit Dubertret (2) , Emmanuel Lhuillier (4)

1 INSP-E6 - Physico-chimie et dynamique des surfaces
2 LPEM - Laboratoire de Physique et d'Etude des Matériaux (UMR 8213)
3 MONARIS - De la Molécule aux Nanos-objets : Réactivité, Interactions et Spectroscopies
4 INSP - Institut des Nanosciences de Paris

We report the synthesis of nanocrystals with an 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 to 200 nm. This is used to tune the absorption of the nanocrystals all over the infrared range up to terahertz (from 2 to 65 μm for absorption peak and even 200 μm for cutoff wavelength). The interest for this procedure is not limited to large sizes since for small objects we demonstrate low aggregation and good shape control (i.e., spherical object) while using nonexpansive and simple mercury halogenide precursors. By integrating these nanocrystals into an electrolyte-gated transistor, we evidence a change of carrier density from p-doped to n-doped as the confinement is vanishing.

Domaines: Matériaux; Matière Condensée [cond-mat]

Nicolas Goubet, Amardeep Jagtap, Clément Livache, Bertille Martinez, Hervé Portalès, et al.. Terahertz HgTe Nanocrystals: Beyond Confinement. Journal of the American Chemical Society, 2018, 140 (15), pp.5033-5036. ⟨10.1021/jacs.8b02039⟩. ⟨hal-01764916⟩