title: Strongly Confined HgTe 2D Nanoplatelets as Narrow Near-Infrared Emitters.
abstract: Two-dimensional colloidal nanoplatelets (NPLs), owing to the atomic-level control of their confined direction (i.e., no inhomogeneous broadening), have demonstrated improved photoluminescence (PL) line widths for cadmium chalcogenide-based nanocrystals. Here we use cation exchange to synthesize mercury chalcogenide NPLs. Appropriate control of reaction kinetics enables the 2D morphology of the NPLs to be maintained during the cation exchange. HgTe and HgSe NPLs have significantly improved optical features compared to existing materials with similar band gaps. The PL line width of HgTe NPLs (40 nm full width at half-maximum, centered at 880 nm) is a factor of 2 smaller than typical PbS nanocrystals (NCs) emitting at the same wavelength. The PL has a lifetime of 50 ns, almost 2 orders of magnitude shorter than small PbS colloidal quantum dots (CQDs), and a quantum yield of ∼10%, almost 2 orders of magnitude shorter than small PbS colloidal quantum dots (CQDs). These materials are promising for a large variety of applications spanning from telecommunications to the design of colloidal topological insulators.
authors.affiliation: Laboratoire de Physique et d'Étude des Matériaux, PSL Research University, CNRS UMR 8213, ESPCI ParisTech , 10 rue Vauquelin, 75005 Paris, France.
authors.forename: Eva
authors.initials: E
authors.lastname: Izquierdo
authors.affiliation: Laboratoire de Physique et d'Étude des Matériaux, PSL Research University, CNRS UMR 8213, ESPCI ParisTech , 10 rue Vauquelin, 75005 Paris, France.
authors.forename: Adrien
authors.initials: A
authors.lastname: Robin
authors.affiliation: Voxtel, Inc., and CAMCOR 1241, University of Oregon , Eugene, Oregon 97403, United States.
authors.forename: Sean
authors.initials: S
authors.lastname: Keuleyan
authors.affiliation: Laboratoire de Physique et d'Étude des Matériaux, PSL Research University, CNRS UMR 8213, ESPCI ParisTech , 10 rue Vauquelin, 75005 Paris, France.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Lequeux
authors.affiliation: Institut des Nanosciences de Paris, CNRS-UMR 7588, Sorbonne Universités, UPMC Univ Paris 06 , F-75005 Paris, France.
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Lhuillier
authors.affiliation: Laboratoire de Physique et d'Étude des Matériaux, PSL Research University, CNRS UMR 8213, ESPCI ParisTech , 10 rue Vauquelin, 75005 Paris, France.
authors.forename: Sandrine
authors.initials: S
authors.lastname: Ithurria