title: Solution Synthesis Approach to Colloidal Cesium Lead Halide Perovskite Nanoplatelets with Monolayer-Level Thickness Control.
abstract: We report a colloidal synthesis approach to CsPbBr3 nanoplatelets (NPLs). The nucleation and growth of the platelets, which takes place at room temperature, is triggered by the injection of acetone in a mixture of precursors that would remain unreactive otherwise. The low growth temperature enables the control of the plate thickness, which can be precisely tuned from 3 to 5 monolayers. The strong two-dimensional confinement of the carriers at such small vertical sizes is responsible for a narrow PL, strong excitonic absorption, and a blue shift of the optical band gap by more than 0.47 eV compared to that of bulk CsPbBr3. We also show that the composition of the NPLs can be varied all the way to CsPbBr3 or CsPbI3 by anion exchange, with preservation of the size and shape of the starting particles. The blue fluorescent CsPbCl3 NPLs represent a new member of the scarcely populated group of blue-emitting colloidal nanocrystals. The exciton dynamics were found to be independent of the extent of 2D confinement in these platelets, and this was supported by band structure calculations.
authors.affiliation: Nanochemistry Department, Istituto Italiano di Tecnologia , Via Morego 30, 16163 Genova, Italy.|Università degli Studi di Genova , Via Dodecaneso, 31, 16146, Genova, Italy.
authors.forename: Quinten A
authors.initials: QA
authors.lastname: Akkerman
authors.affiliation: Center for Nano Science and Technology @Polimi, Istituto Italiano di Tecnologia , Via Giovanni Pascoli 70/3, 20133 Milano, Italy.|Dipartimento di Fisica, Politecnico di Milano , Piazza Leonardo da Vinci, 32, 20133 Milano, Italy.
authors.forename: Silvia Genaro
authors.initials: SG
authors.lastname: Motti
authors.affiliation: Center for Nano Science and Technology @Polimi, Istituto Italiano di Tecnologia , Via Giovanni Pascoli 70/3, 20133 Milano, Italy.
authors.forename: Ajay Ram
authors.initials: AR
authors.lastname: Srimath Kandada
authors.affiliation: Computational Laboratory for Hybrid/Organic Photovoltaics, CNR-ISTM , Via Elce di Sotto, 06123 Perugia, Italy.
authors.forename: Edoardo
authors.initials: E
authors.lastname: Mosconi
authors.affiliation: Center for Nano Science and Technology @Polimi, Istituto Italiano di Tecnologia , Via Giovanni Pascoli 70/3, 20133 Milano, Italy.|Dipartimento di Fisica, Politecnico di Milano , Piazza Leonardo da Vinci, 32, 20133 Milano, Italy.
authors.forename: Valerio
authors.initials: V
authors.lastname: D'Innocenzo
authors.affiliation: Nanochemistry Department, Istituto Italiano di Tecnologia , Via Morego 30, 16163 Genova, Italy.|IMEM-CNR , Parco Area delle Scienze 37/A, 43124 Parma, Italy.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Bertoni
authors.affiliation: Nanochemistry Department, Istituto Italiano di Tecnologia , Via Morego 30, 16163 Genova, Italy.
authors.forename: Sergio
authors.initials: S
authors.lastname: Marras
authors.affiliation: Centre for Innovation and Enterprise, OxfordPV Ltd. , Begbroke Science Park, Woodstock Road, Oxford OX5 1PF, United Kingdom.
authors.forename: Brett A
authors.initials: BA
authors.lastname: Kamino
authors.affiliation: Centre for Innovation and Enterprise, OxfordPV Ltd. , Begbroke Science Park, Woodstock Road, Oxford OX5 1PF, United Kingdom.
authors.forename: Laura
authors.initials: L
authors.lastname: Miranda
authors.affiliation: CompuNet, Istituto Italiano di Tecnologia , Via Morego 30, 16163 Genova, Italy.|Computational Laboratory for Hybrid/Organic Photovoltaics, CNR-ISTM , Via Elce di Sotto, 06123 Perugia, Italy.
authors.forename: Filippo
authors.initials: F
authors.lastname: De Angelis
authors.affiliation: Center for Nano Science and Technology @Polimi, Istituto Italiano di Tecnologia , Via Giovanni Pascoli 70/3, 20133 Milano, Italy.
authors.forename: Annamaria
authors.initials: A
authors.lastname: Petrozza
authors.affiliation: Nanochemistry Department, Istituto Italiano di Tecnologia , Via Morego 30, 16163 Genova, Italy.
authors.forename: Mirko
authors.initials: M
authors.lastname: Prato
authors.affiliation: Nanochemistry Department, Istituto Italiano di Tecnologia , Via Morego 30, 16163 Genova, Italy.
authors.forename: Liberato
authors.initials: L
authors.lastname: Manna