title: From dilute isovalent substitution to alloying in CdSeTe nanoplatelets.
abstract: Cadmium chalcogenide nanoplatelet (NPL) synthesis has recently witnessed a significant advance in the production of more elaborate structures such as core/shell and core/crown NPLs. However, controlled doping in these structures has proved difficult because of the restrictive synthetic conditions required for 2D anisotropic growth. Here, we explore the incorporation of tellurium (Te) within CdSe NPLs with Te concentrations ranging from doping to alloying. For Te concentrations higher than ∼30%, the CdSexTe(1-x) NPLs show emission properties characteristic of an alloyed material with a bowing of the band gap for increased concentrations of Te. This behavior is in line with observations in bulk samples and can be put in the context of the transition from a pure material to an alloy. In the dilute doping regime, CdSe:Te NPLs, in comparison to CdSe NPLs, show a distinct photoluminescence (PL) red shift and prolonged emission lifetimes (LTs) associated with Te hole traps which are much deeper than in bulk samples. Furthermore, single particle spectroscopy reveals dramatic modifications in PL properties. In particular, doped NPLs exhibit photon antibunching and emission dynamics significantly modified compared to undoped or alloyed NPLs.
authors.affiliation: Department of Physics of Complex Systems, Weizmann Institute of Science, 76100 Rehovot, Israel. miri.kazes@weizmann.ac.il.
authors.forename: Ron
authors.initials: R
authors.lastname: Tenne
authors.affiliation: ESPCI ParisTech, PSL Research University, CNRS, Sorbonne Universités, UPMC Univ. Paris 6; LPEM, 10 rue Vauquelin, F-75231 Paris Cedex 5, France and Nexdot, 10 Rue Vauquelin, 75005 Paris, France.
authors.forename: Silvia
authors.initials: S
authors.lastname: Pedetti
authors.affiliation: Department of Physics of Complex Systems, Weizmann Institute of Science, 76100 Rehovot, Israel. miri.kazes@weizmann.ac.il.
authors.forename: Miri
authors.initials: M
authors.lastname: Kazes
authors.affiliation: ESPCI ParisTech, PSL Research University, CNRS, Sorbonne Universités, UPMC Univ. Paris 6; LPEM, 10 rue Vauquelin, F-75231 Paris Cedex 5, France.
authors.forename: Sandrine
authors.initials: S
authors.lastname: Ithurria
authors.affiliation: Department of Chemical Research Support, Weizmann Institute of Science, 76100 Rehovot, Israel.
authors.forename: Lothar
authors.initials: L
authors.lastname: Houben
authors.affiliation: Nexdot, 10 Rue Vauquelin, 75005 Paris, France.
authors.forename: Brice
authors.initials: B
authors.lastname: Nadal
authors.affiliation: Department of Physics of Complex Systems, Weizmann Institute of Science, 76100 Rehovot, Israel. miri.kazes@weizmann.ac.il.
authors.forename: Dan
authors.initials: D
authors.lastname: Oron
authors.affiliation: ESPCI ParisTech, PSL Research University, CNRS, Sorbonne Universités, UPMC Univ. Paris 6; LPEM, 10 rue Vauquelin, F-75231 Paris Cedex 5, France.
authors.forename: Benoit
authors.initials: B
authors.lastname: Dubertret