title: Scalable Ligand-Mediated Transport Synthesis of Organic-Inorganic Hybrid Perovskite Nanocrystals with Resolved Electronic Structure and Ultrafast Dynamics.
abstract: Colloidal perovskite nanocrystals support bright, narrow PL tunable over the visible spectrum. However, bandgap tuning of these materials remains limited to laboratory-scale syntheses. In this work, we present a polar-solvent-free ligand-mediated transport synthesis of high-quality organic-inorganic perovskite nanocrystals under ambient conditions with photoluminescence quantum yields up to 97%. Our synthesis employs a ligand-mediated transport mechanism that circumvents the need for exquisite external control (e.g., temperature control, inert-gas protection, dropwise addition of reagents) required by other methods due to extremely fast reaction kinetics. In the ligand-mediated transport mechanism, multiple equilibria cooperatively dictate reaction rates and enable precise control over NC size. These small nanocrystals exhibit high photoluminescence quantum yields due to quantum confinement. Nanosecond transient absorption spectroscopy experiments reveal a fluence-independent PL decay originating from exciton recombination. Two-dimensional electronic spectroscopy resolves multiple spectral features reflecting the electronic structure of the nanocrystals. The resolved features exhibit size-dependent spectral positions, further indicating the synthesized nanocrystals are quantum-confined.
authors.forename: Lili
authors.initials: L
authors.lastname: Wang
authors.forename: Nicholas E
authors.initials: NE
authors.lastname: Williams
authors.forename: Edward W
authors.initials: EW
authors.lastname: Malachosky
authors.forename: John P
authors.initials: JP
authors.lastname: Otto
authors.affiliation: Chemical Sciences and Engineering Division, Argonne National Laboratory , 9700 South Cass Avenue, Argonne, Illinois 60439, United States.
authors.forename: Dugan
authors.initials: D
authors.lastname: Hayes
authors.forename: Ryan E
authors.initials: RE
authors.lastname: Wood
authors.forename: Philippe
authors.identifier: 0000-0003-0178-6255
authors.initials: P
authors.lastname: Guyot-Sionnest
authors.forename: Gregory S
authors.identifier: 0000-0002-6740-5243
authors.initials: GS
authors.lastname: Engel
keywords: 2DES; ambient condition synthesis; perovskite nanocrystals; quantum-beating signals; ultrafast