Mesoscale Growth and Assembly of Bright Luminescent Organolead Halide Perovskite Quantum Wires Meghan B. Teunis, † Atanu Jana, †,⊥ Poulami Dutta, ‡ Merrell A. Johnson, †,# Manik Mandal, § Barry B. Muhoberac, † and Rajesh Sardar* ,†,∥ † Department of Chemistry and Chemical Biology, Indiana University−Purdue University Indianapolis, 402 N. Blackford Street, Indianapolis, Indiana 46202, United States ‡ Department of Chemistry, Michigan State University, 578 South Shaw Lane, East Lansing, Michigan 48824, United States § Department of Chemistry, Lehigh University, 6 East Packer Avenue, Bethlehem, Pennsylvania 18015, United States ∥ Integrated Nanosystems Development Institute, Indiana University−Purdue University Indianapolis, 402 N. Blackford Street, Indianapolis, Indiana 46202, United States * S Supporting Information ABSTRACT: The long carrier lifetimes and low nonradiative recombination rates of organic−inorganic hybrid perovskites have opened new avenues in fabrication of highly efficient solar cells, light-emitting diodes, and lasers. Controlling shapes and organization of newly synthesized perovskite nanostructures should greatly expand their practical application. Here, we report a colloidal synthetic approach to the preparation of methylammonium lead bromide (CH 3 NH 3 PbBr 3 ) quantum wires by controlling their surface ligand chemistry to achieve well-defined superstructures. Quantum wire formation was proceeded by the appearance of pearl-necklace assemblies of spherical CH 3 NH 3 PbBr 3 nanocrystals as intermediates formed mainly through dipolar interactions. The diameter of the quantum wires (∼3.8 nm) was found to be larger than the precursor spherical CH 3 NH 3 PbBr 3 nanocrystals (∼2.4 nm). Our experimental findings support mesoscale growth and assembly into CH 3 NH 3 PbBr 3 quantum wires driven by cooperative interactions between nanocrystals caused by van der Waals interactions and chain interdigitation of surface passivating ligands. The quantum wires displayed an aspect ratio as high as 250 with photoluminescence quantum yield of ∼60% and lifetime of ∼90 ns, and were aligned in bundles. Our simple colloidal synthetic approach and detailed characterization will inspire rational design of methodologies to prepare diverse anisotropic semiconductor perovskite nanostructures and superstructures, which together will increase the versatility and performance of perovskite materials in optoelectronic and photovoltaic device applications. ■ INTRODUCTION The early work by Mitzi and co-workers 1 on semiconductor organic−inorganic lead halide perovskites has expedited the synthesis of Earth-abundant organometal perovskite bulk materials, which have shown promise in their application in fabrication of efficient light-emitting diodes 2 and lasers. 3 Following the first report, 4 organolead halide perovskites are now successfully used as light absorbers in solar cells devices 5−13 with certified power conversion efficiency of 20.1%. 14 The long carrier diffusion lengths, 12,15,16 faster charge carrier mobility, 12,17 larger absorption cross-section, and ambipolar charge transport character 18 make organic−inorganic lead halide perovskites ideal materials to design highly efficient solar cells with power conversion efficiency as high as 30%, as demonstrated for silicon and gallium arsenide materials. 14 However, the charge transport properties and carrier lifetimes of the mesoscopic perovskite bulk materials in these solid-state devices can be further improved through understanding the influence of shape on photophysical and electronic properties Received: May 3, 2016 Revised: June 21, 2016 Published: July 15, 2016 Article pubs.acs.org/cm © 2016 American Chemical Society 5043 DOI: 10.1021/acs.chemmater.6b01793 Chem. Mater. 2016, 28, 5043−5054 Downloaded via ULSAN NATL INST SCIENCE AND TECHLGY on November 28, 2018 at 13:05:01 (UTC). See https://pubs.acs.org/sharingguidelines for options on how to legitimately share published articles.