1
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Justice Babu K, Chazhoor Asokan A, Shukla A, Kaur A, Sachdeva M, Ghosh HN. Ultrafast Interfacial Charge Transfer in Anisotropic One-Dimensional CsPbBr 3/Pt Epitaxial Heterostructure. J Phys Chem Lett 2024; 15:9677-9685. [PMID: 39283702 DOI: 10.1021/acs.jpclett.4c01853] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/27/2024]
Abstract
Colloidal one-dimensional (1D) perovskite nanorods (NRs) and metal epitaxial heterostructures (HSs) are the promising class of new materials for efficient photovoltaic and photocatalytic applications. Besides, fundamental photophysical properties and its device applications of 1D perovskite-metal HSs are limited due to their challenging synthetic protocols and difficulties in forming epitaxial growth between covalent and ionic bonds. Herein, we have synthesized the CsPbBr3 perovskite NRs-platinum (Pt) nanoparticles (NPs) (CsPbBr3/Pt) epitaxial HS using cation exchange followed by chemical reduction methods with the orthorhombic Cs2CuBr4 NRs. Here, the tertiary ammonium ions extensively helped to form the 1D Cs2CuBr4, CsPbBr3 NRs, and CsPbBr3/Pt HSs. For CsPbBr3/Pt HSs an epitaxial relationship has been established in the (020) plane of orthorhombic CsPbBr3 with the (020) plane of cubic Pt. Further, femtosecond transient absorption (TA) spectroscopy was employed to study the charge carrier dynamics of CsPbBr3/Pt HS. Upon 420 nm photoexcitation, excitons in the conduction band of CsPbBr3 NRs dissociate by electron transfer (with an ultrafast time of 1.1 ps) to the Pt domain. In addition, charge transfer (CT) was also demonstrated in the CsPbBr3/Pt HS, which is ascribed to strong electron coupling and epitaxial growth between CsPbBr3 and Pt states. This extensive understanding of the electron transfer dynamics of CsPbBr3/Pt epitaxial HS may pave the way to designing highly efficient photovoltaic and photocatalytic applications.
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Affiliation(s)
| | | | - Ayushi Shukla
- Institute of Nano Science and Technology, Mohali, Punjab 140306, India
| | - Arshdeep Kaur
- Institute of Nano Science and Technology, Mohali, Punjab 140306, India
| | - Manvi Sachdeva
- Institute of Nano Science and Technology, Mohali, Punjab 140306, India
| | - Hirendra N Ghosh
- School of Chemical Science, National Institute of Science Education and Research, Jatni, Bhubaneswar, Odisha 752050, India
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2
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Bera S, Tripathi A, Titus T, Sethi NM, Das R, Afreen, Adarsh KV, Thomas KG, Pradhan N. CsPbBr 3 Perovskite Crack Platelet Nanocrystals and Their Biexciton Generation. J Am Chem Soc 2024; 146:20300-20311. [PMID: 39005055 DOI: 10.1021/jacs.4c05803] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/16/2024]
Abstract
Lead halide perovskite nanocrystals have been extensively studied in recent years as efficient optical materials for their bright and color-tunable emissions. However, these are mostly confined to their 3D nanocrystals and limited to the anisotropic nanostructures. By exploring the Cs-sublattice-induced metal(II) ion exchange with Pb(II), crack CsPbBr3 perovskite platelet nanocrystals having polar surfaces in all three directions are reported here, which remained different than reported standard square platelets. The crack platelets are also passivated with halides to enhance their brightness. Further, as these crack and passivated crack platelets have defects and polar surfaces, the exciton and biexciton generation in these platelets is investigated using femtosecond photoluminescence and transient absorption measurement at ambient as well as cryogenic temperatures, correlated with time-resolved single-particle photoluminescence spectroscopy, and compared with standard square platelets having nonpolar facets. These investigations revealed that the crack platelets and passivated crack platelets possess enhanced biexciton emission compared to square platelets due to the presence of polar surfaces in all three directions. These results provide insights into not only the design of the anisotropic nanostructures of ionic nanocrystals but also the possibility of tuning the single exciton to biexciton generation efficiency, which has potential applications in optoelectronic systems.
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Affiliation(s)
- Suman Bera
- School of Materials Sciences, Indian Association for the Cultivation of Science, Kolkata, West Bengal 700032, India
| | - Akash Tripathi
- Department of Physics, Indian Institute of Science Education and Research, Bhopal, Madhya Pradesh 462066, India
| | - Timi Titus
- School of Chemistry, Indian Institute of Science Education and Research Thiruvananthapuram, Vithura, Thiruvananthapuram, Kerala 695551, India
| | - Nilesh Monohar Sethi
- School of Materials Sciences, Indian Association for the Cultivation of Science, Kolkata, West Bengal 700032, India
| | - Rajdeep Das
- School of Materials Sciences, Indian Association for the Cultivation of Science, Kolkata, West Bengal 700032, India
| | - Afreen
- Department of Physics, Indian Institute of Science Education and Research, Bhopal, Madhya Pradesh 462066, India
| | - K V Adarsh
- Department of Physics, Indian Institute of Science Education and Research, Bhopal, Madhya Pradesh 462066, India
| | - K George Thomas
- School of Chemistry, Indian Institute of Science Education and Research Thiruvananthapuram, Vithura, Thiruvananthapuram, Kerala 695551, India
| | - Narayan Pradhan
- School of Materials Sciences, Indian Association for the Cultivation of Science, Kolkata, West Bengal 700032, India
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3
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Garai A, Vishnu EK, Banerjee S, Nair AAK, Bera S, Thomas KG, Pradhan N. Vertex-Oriented Cube-Connected Pattern in CsPbBr 3 Perovskite Nanorods and Their Optical Properties: An Ensemble to Single-Particle Study. J Am Chem Soc 2023. [PMID: 37317943 DOI: 10.1021/jacs.3c03759] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
The design of cube-connected nanorods is accomplished by connecting seed nanocrystals of a defined shape in a particular orientation or by etching selective facets of preformed nanorods. In lead halide perovskite nanostructures, which retain mostly a hexahedron cube shape, such patterned nanorods can be designed with the anisotropic direction along the edge, vertex, or facet of seed cubes. Combining the Cs-sublattice platform for transforming metal halides to halide perovskites with facet-specific ligand binding chemistry, herein, vertex-oriented patterning of nanocubes in one-dimensional (1D) rod structures is reported. By tuning the length of host metal halides, their lengths could also be tuned from 100 nm to nearly 1000 nm. The symmetry of the hexagonal phase of host halide CsCdBr3 and product orthorhombic CsPbBr3 helped in maintaining the vertex [201] as the anisotropic direction. Neutral exciton recombination rates, extracted from photoluminescence blinking traces, showed a systematic increase from isolated cubes to cube-connected nanorods of various lengths. Efficient coupling of wave functions in vertex-oriented cube assemblies permits exciton delocalization. Our findings on carrier delocalization in cube-connected nanorods along their vertex direction having minimum interfacial contacts provide valuable insights into the fundamental chemistry of assembling anisotropic halide perovskite nanostructures as conducting wires.
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Affiliation(s)
- Arghyadeep Garai
- School of Materials Sciences, Indian Association for the Cultivation of Science, Kolkata 700032, India
| | - E Krishnan Vishnu
- School of Chemistry, Indian Institute of Science Education and Research Thiruvananthapuram (IISER TVM), Vithura, Thiruvananthapuram 695551, India
| | - Souvik Banerjee
- School of Materials Sciences, Indian Association for the Cultivation of Science, Kolkata 700032, India
| | - Anoop Ajaya Kumar Nair
- School of Chemistry, Indian Institute of Science Education and Research Thiruvananthapuram (IISER TVM), Vithura, Thiruvananthapuram 695551, India
| | - Suman Bera
- School of Materials Sciences, Indian Association for the Cultivation of Science, Kolkata 700032, India
| | - K George Thomas
- School of Chemistry, Indian Institute of Science Education and Research Thiruvananthapuram (IISER TVM), Vithura, Thiruvananthapuram 695551, India
| | - Narayan Pradhan
- School of Materials Sciences, Indian Association for the Cultivation of Science, Kolkata 700032, India
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4
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Behera RK, Bera S, Pradhan N. Hexahedron Symmetry and Multidirectional Facet Coupling of Orthorhombic CsPbBr 3 Nanocrystals. ACS NANO 2023; 17:7007-7016. [PMID: 36996308 DOI: 10.1021/acsnano.3c01617] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/19/2023]
Abstract
The cube shape of orthorhombic phase CsPbBr3 nanocrystals possesses the ability of selective facet packing that leads to 1D, 2D, and 3D nanostructures. In solution, their transformation with linear one-dimensional packing to nanorods/nanowires is extensively studied. Here, multifacet coupling in two directions of the truncated cube nanocrystals to rod couples and then to single-crystalline rectangular rods is reported. With extensive high-resolution transmission electron microscopy image analysis, length and width directions of these nanorods are derived. For the seed cube structures, finding {110} and {002} facets has remained difficult as these possess the hexahedron symmetry and their size remains smaller; however, for nanorods, these planes and the ⟨110⟩ and ⟨001⟩ directions are clearly identified. From nanocrystal to nanorod formation, the alignment directions are observed as random (as shown in the abstract graphic), and this could vary from one to the other rods obtained in the same batch of samples. Moreover, seed nanocrystal connections are derived here as not random and are rather induced by addition of the calculated amount of additional Pb(II). The same has also been extended to nanocubes obtained from different literature methods. It is predicted that a Pb-bromide buffer octahedra layer was created to connect two cubes, and this can connect along one, two, or even more facets of cubes simultaneously to connect other cubes and form different nanostructures. Hence, these results here provide some basic fundamentals of seed cube connections, the driving force to connect those, trapping the intermediate to visualize their alignments for attachments, and identifying and establishing the orthorhombic ⟨110⟩ and ⟨001⟩ directions of the length and width of CsPbBr3 nanostructures.
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Affiliation(s)
- Rakesh Kumar Behera
- School of Materials Sciences, Indian Association for the Cultivation of Science, Kolkata 700032, India
| | - Suman Bera
- School of Materials Sciences, Indian Association for the Cultivation of Science, Kolkata 700032, India
| | - Narayan Pradhan
- School of Materials Sciences, Indian Association for the Cultivation of Science, Kolkata 700032, India
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5
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Sheikh T, Anilkumar GM, Das T, Rahman A, Chakraborty S, Nag A. Combining π-Conjugation and Cation-π Interaction for Water-Stable and Photoconductive One-Dimensional Hybrid Lead Bromide. J Phys Chem Lett 2023; 14:1870-1876. [PMID: 36779963 DOI: 10.1021/acs.jpclett.2c03861] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
Hybrid lead halide perovskites and their derivatives are important optoelectronic materials but suffer from water instability. Combining both the optoelectronics and the water stability of such systems is a major challenge in material design today. To address this issue, we employ the well-known π-conjugation and cation-π interaction concepts in designing a hybrid lead halide perovskite derivative system. (4,4'-VDP)Pb2Br6 (VDP = vinylenedipyridinium) single crystals are prepared. They have a one-dimensional (1D) arrangement of inorganic Pb-Br sublattices connected via the 4,4'-VDP organic sublattice. The π-conjugation in the 4,4'-VDP sublattice allows electronic communication between the 1D Pb-Br units, reducing the band gap and improving the photoconductivity. Importantly, N+ of one 4,4'-VDP molecular ion interacts with the π-electron cloud of the adjacent one. This intermolecular cation-π interaction extends throughout the organic sublattice, making the hybrid crystal stable when stored under water for more than a year without requiring any encapsulations.
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Affiliation(s)
- Tariq Sheikh
- Department of Chemistry, Indian Institute of Science Education and Research (IISER), Pune 411008, India
| | - Gokul M Anilkumar
- Department of Physics, Indian Institute of Science Education and Research (IISER), Pune 411008, India
| | - Tisita Das
- Materials Theory for Energy Scavenging (MATES) Lab, Harish-Chandra Research Institute (HRI) Allahabad, HBNI, Chhatnag Road, Jhunsi, Prayagraj (Allahabad) 211019, India
| | - Atikur Rahman
- Department of Physics, Indian Institute of Science Education and Research (IISER), Pune 411008, India
| | - Sudip Chakraborty
- Materials Theory for Energy Scavenging (MATES) Lab, Harish-Chandra Research Institute (HRI) Allahabad, HBNI, Chhatnag Road, Jhunsi, Prayagraj (Allahabad) 211019, India
| | - Angshuman Nag
- Department of Chemistry, Indian Institute of Science Education and Research (IISER), Pune 411008, India
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6
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Banerjee S, Bera S, Pradhan N. Chemically Sculpturing the Facets of CsPbBr 3 Perovskite Platelet Nanocrystals. ACS NANO 2023; 17:678-686. [PMID: 36577129 DOI: 10.1021/acsnano.2c10107] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
The facet chemistry of lead halide perovskite nanocrystals is critically important for determining their shape and interface ligand binding. In colloidal nanocrystals, these are mostly controlled by adopting specific synthetic strategies with a selection of the appropriate reactants. However, using selected ligands, the surface of preformed nanocrystals can be reconstructed without altering the crystal phase and lattice structure of their core. This has been shown here for hexagonal-shaped orthorhombic CsPbBr3 platelet nanocrystals. When oleylammonium bromide was added to these postsynthesized platelets, all six edges and two planar facets are transformed from flat to wavy structures. With a variation in concentration, the crest-to-crest distance of these wavy platelets are also tuned. These became possible because of the oleylammonium ions, which changed the {200}, {012} and {020} facets of orthorhombic phase of CsPbBr3 to the more compatible {110} and {002} facets simply by surface atom dissolution. This was also observed for multisegmented platelets having multiple junctions and even for platelets having a size of more than 200 nm. While shape modulations in ionic halide perovskite nanocrystals still face synthetic challenges, these results of surface reconstruction provide strong evidence of the possibility of sculpturing surface facets and shape changes in these nanostructures.
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Affiliation(s)
- Souvik Banerjee
- School of Materials Sciences, Indian Association for the Cultivation of Science, Kolkata 700032, India
| | - Suman Bera
- School of Materials Sciences, Indian Association for the Cultivation of Science, Kolkata 700032, India
| | - Narayan Pradhan
- School of Materials Sciences, Indian Association for the Cultivation of Science, Kolkata 700032, India
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7
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Junot G, Leyva SG, Pauer C, Calero C, Pagonabarraga I, Liedl T, Tavacoli J, Tierno P. Friction Induces Anisotropic Propulsion in Sliding Magnetic Microtriangles. NANO LETTERS 2022; 22:7408-7414. [PMID: 36062566 PMCID: PMC9523709 DOI: 10.1021/acs.nanolett.2c02295] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Revised: 08/22/2022] [Indexed: 06/15/2023]
Abstract
In viscous fluids, motile microentities such as bacteria or artificial swimmers often display different transport modes than macroscopic ones. A current challenge in the field aims at using friction asymmetry to steer the motion of microscopic particles. Here we show that lithographically shaped magnetic microtriangles undergo a series of complex transport modes when driven by a precessing magnetic field, including a surfing-like drift close to the bottom plane. In this regime, we exploit the triangle asymmetric shape to obtain a transversal drift which is later used to transport the microtriangle in any direction along the plane. We explain this friction-induced anisotropic sliding with a minimal numerical model capable to reproduce the experimental results. Due to the flexibility offered by soft-lithographic sculpturing, our method to guide anisotropic-shaped magnetic microcomposites can be potentially extended to many other field responsive structures operating in fluid media.
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Affiliation(s)
- Gaspard Junot
- Departament
de Física de la Matèria Condensada, Universitat de Barcelona, 08028 Barcelona, Spain
| | - Sergi G. Leyva
- Departament
de Física de la Matèria Condensada, Universitat de Barcelona, 08028 Barcelona, Spain
- Universitat
de Barcelona Institute of Complex Systems (UBICS), Universitat de Barcelona, 08028, Barcelona, Spain
| | - Christoph Pauer
- Faculty
of Physics and Center for Nano Science, Ludwig-Maximilians-Universität, Geschwister-Scholl-Platz 1, München 80539, Germany
| | - Carles Calero
- Departament
de Física de la Matèria Condensada, Universitat de Barcelona, 08028 Barcelona, Spain
- Institut
de Nanociéncia i Nanotecnologia, Universitat de Barcelona, 08028, Barcelona, Spain
| | - Ignacio Pagonabarraga
- Departament
de Física de la Matèria Condensada, Universitat de Barcelona, 08028 Barcelona, Spain
- Universitat
de Barcelona Institute of Complex Systems (UBICS), Universitat de Barcelona, 08028, Barcelona, Spain
- CECAM,
Centre Européen de Calcul Atomique et Moléculaire, École Polytechnique Fédérale
de Lausanne (EPFL), Batochime, Avenue Forel 2, 1015 Lausanne, Switzerland
| | - Tim Liedl
- Faculty
of Physics and Center for Nano Science, Ludwig-Maximilians-Universität, Geschwister-Scholl-Platz 1, München 80539, Germany
| | - Joe Tavacoli
- Faculty
of Physics and Center for Nano Science, Ludwig-Maximilians-Universität, Geschwister-Scholl-Platz 1, München 80539, Germany
| | - Pietro Tierno
- Universitat
de Barcelona Institute of Complex Systems (UBICS), Universitat de Barcelona, 08028, Barcelona, Spain
- Institut
de Nanociéncia i Nanotecnologia, Universitat de Barcelona, 08028, Barcelona, Spain
- Departament
de Física de la Matèria Condensada, Universitat de Barcelona, 08028, Barcelona, Spain
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8
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Nasipuri D, Patra A, Bera S, Dutta SK, Pradhan N. Nucleophile-Controlled Halide Release from the Substitution Reaction of Haloketone for Facet Tuning and Manganese Doping in CsPbCl 3 Nanocrystals. J Phys Chem Lett 2022; 13:4506-4512. [PMID: 35575707 DOI: 10.1021/acs.jpclett.2c01084] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Halide content of the reaction medium not only enhances the brightness of CsPbCl3 nanocrystals but also, control the shape modulations as well as doping Mn(II) in these host nanocrystals. Correlating both the shape effect and doping, herein, an in situ reaction of nucleophile-controlled halide release was explored for monitoring facets modulations and doping in CsPbCl3 nanocrystals. This was performed using alkyl amine as nucleophile which reacted with α-halo ketone, phenacyl chloride, to release chloride ions. Increase in amine concentration which released more Cl ions, reduced the possibility of shape transformation from perfect to truncated cubes during annealing. Similarly, for Mn(II) doping, the dopant photoluminescence intensity remained directly proportional to the amount of introduced amine nucleophiles. Quality of both doped and undoped nanocrystals obtained in this procedure remained unparallel and the method provided a strong correlation of rate of halide release with both facet modulations and doping in these nanocrystals.
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Affiliation(s)
- Diptam Nasipuri
- School of Materials Sciences, Indian Association for the Cultivation of Science, Kolkata 700032, India
| | - Avijit Patra
- School of Materials Sciences, Indian Association for the Cultivation of Science, Kolkata 700032, India
| | - Suman Bera
- School of Materials Sciences, Indian Association for the Cultivation of Science, Kolkata 700032, India
| | - Sumit Kumar Dutta
- School of Materials Sciences, Indian Association for the Cultivation of Science, Kolkata 700032, India
| | - Narayan Pradhan
- School of Materials Sciences, Indian Association for the Cultivation of Science, Kolkata 700032, India
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9
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Wen JR, Rodríguez Ortiz FA, Champ A, Sheldon MT. Kinetic Control for Continuously Tunable Lattice Parameters, Size, and Composition during CsPbX 3 (X = Cl, Br, I) Nanorod Synthesis. ACS NANO 2022; 16:8318-8328. [PMID: 35544608 DOI: 10.1021/acsnano.2c02474] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
The fast kinetics of all-inorganic CsPbX3 (X = Cl, Br, or I) nanocrystal growth entail that many synthetic strategies for structural control established in other semiconductor systems do not apply. Rather, products are often determined by thermodynamic factors, limiting the range of synthetic outcomes and functionality. In this study, we show how reaction kinetics are significantly slowed if nanocrystals are prepared using a dual injection strategy that moderates the crucial interaction between cesium and halide during nucleation and growth. The result is highly uniform nanorod or cuboid nanocrystals with a controllable size and aspect ratio across the quantum confinement regime, obtainable for both pure and mixed halide compositions. Further, the crystal lattice is continuously tunable between the tetragonal (I4/mcm) and orthorhombic (Pbnm) phases, independent of the overall nanorod morphology, enabling significantly more sophisticated structure-property relationships that can be tailored during this kinetically controlled synthesis.
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Affiliation(s)
- Je-Ruei Wen
- Department of Chemistry, Texas A&M University, College Station, Texas 77843-3255, United States
| | | | - Anna Champ
- Department of Chemistry, Texas A&M University, College Station, Texas 77843-3255, United States
| | - Matthew T Sheldon
- Department of Chemistry, Texas A&M University, College Station, Texas 77843-3255, United States
- Department of Materials Science & Engineering, Texas A&M University, College Station, Texas 77843-3255, United States
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10
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Bera S, Banerjee S, Das R, Pradhan N. Tuning Crystal Plane Orientation in Multijunction and Hexagonal Single Crystalline CsPbBr 3 Perovskite Disc Nanocrystals. J Am Chem Soc 2022; 144:7430-7440. [DOI: 10.1021/jacs.2c01969] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Suman Bera
- School of Materials Sciences, Indian Association for the Cultivation of Science, Kolkata 700032, India
| | - Souvik Banerjee
- School of Materials Sciences, Indian Association for the Cultivation of Science, Kolkata 700032, India
| | - Rajdeep Das
- School of Materials Sciences, Indian Association for the Cultivation of Science, Kolkata 700032, India
| | - Narayan Pradhan
- School of Materials Sciences, Indian Association for the Cultivation of Science, Kolkata 700032, India
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11
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Chakkamalayath J, Hartland GV, Kamat PV. Photoinduced Transformation of Cs 2Au 2Br 6 into CsPbBr 3 Nanocrystals. J Phys Chem Lett 2022; 13:2921-2927. [PMID: 35343694 DOI: 10.1021/acs.jpclett.2c00473] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Lead-free halide double perovskites offer an environmentally friendly alternative to lead halide perovskites for designing optoelectronic solar cell devices. One simple approach to synthesize such double halide perovskites is through metal ion exchange. CsPbBr3 nanocrystals undergo exchange of Pb2+ with Au(I)/Au(III) to form double perovskite Cs2Au2Br6. When excited, a majority of the charge carriers undergo quick recombination in contrast to long-lived charge carries of excited CsPbBr3 nanocrystals. This metal ion exchange process is reversible as one can regenerate CsPbBr3 by adding excess PbBr2 to the suspension. Interestingly, when subjected to visible light irradiation, Cs2Au2Br6 nanocrystals eject reduced Au from the lattice as evidenced from the formation of larger gold nanoparticles. The presence of residual Pb2+ ions in the suspension restores the original CsPbBr3 composition. The results presented here provide insight into the dynamic nature of Au within the perovskite lattice under both chemical and light stimuli.
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12
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Bera S, Hudait B, Mondal D, Shyamal S, Mahadevan P, Pradhan N. Transformation of Metal Halides to Facet-Modulated Lead Halide Perovskite Platelet Nanostructures on A-Site Cs-Sublattice Platform. NANO LETTERS 2022; 22:1633-1640. [PMID: 35157475 DOI: 10.1021/acs.nanolett.1c04624] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
The conversion of metal halides to lead halide perovskites with B-site metal ion diffusion has remained a convenient approach for obtaining shape-modulated perovskite nanocrystals. These transformations are typically observed for materials having a common A-site Cs-sublattice platform. However, due to the fast reactions, trapping the interconversion process has been difficult. In an exploration of the tetragonal phase of Cs7Cd3Br13 platelets as the parent material, herein, a slower diffusion of Pb(II) leading to facet-modulated CsPbBr3 platelets is reported. This was expected due to the presence of Cd(II) halide octahedra along with Cd(II) halide tetrahedra in the parent material. This helped in microscopically monitoring their phase transformation via an epitaxially related core/shell intermediate heterostructure. The transformation was also derived and predicted by density functional theory calculations. Further, when the reaction chemistry was tuned, core/shell platelets were transformed to different facet-modulated and hollow CsPbBr3 platelet nanostructures. These platelets having different facets were also explored for catalytic CO2 reduction, and their catalytic rates were compared.
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Affiliation(s)
- Suman Bera
- School of Materials Sciences, Indian Association for the Cultivation of Science, Kolkata 700032, India
| | - Biswajit Hudait
- School of Materials Sciences, Indian Association for the Cultivation of Science, Kolkata 700032, India
| | - Debayan Mondal
- Department of Condensed Matter Physics and Material Science, S. N. Bose National Centre for Basic Sciences, Kolkata 700106, India
| | - Sanjib Shyamal
- School of Materials Sciences, Indian Association for the Cultivation of Science, Kolkata 700032, India
| | - Priya Mahadevan
- Department of Condensed Matter Physics and Material Science, S. N. Bose National Centre for Basic Sciences, Kolkata 700106, India
| | - Narayan Pradhan
- School of Materials Sciences, Indian Association for the Cultivation of Science, Kolkata 700032, India
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13
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Dutta SK, Bera S, Behera RK, Hudait B, Pradhan N. Cs-Lattice Extension and Expansion for Inducing Secondary Growth of CsPbBr 3 Perovskite Nanocrystals. ACS NANO 2021; 15:16183-16193. [PMID: 34636535 DOI: 10.1021/acsnano.1c05053] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
The increase of the stability of perovskite nanocrystals with respect to exposure to polar media, layers growth, or shelling with different materials is in demand. While these are widely studied for metal chalcogenide nanocrystals, it has yet to be explored for perovskite nanocrystals. Even growth of a single monolayer on any facet or on the entire surface of these nanocrystals could not be established yet. To address this, herein, a secondary growth approach leading to creation of a secondary lattice with subsequent expansion on preformed CsPbBr3 perovskite nanocrystals is reported. As direct layer growth by adding precursors was not successful, Cs-lattice extension to preformed CsPbBr3 nanocrystals was performed by coupling CsBr to these nanocrystals. Opening both {110}/{002} and {200} facets of parent CsPbBr3 nanocrystals, CsBr was observed to be connected with lattice matching to the {200} facets. Further with Pb(II) incorporation, the Cs-sublattices of CsBr were expanded to CsPbBr3 and led to cube-couple nanocrystals. However, as cubes in these nanostructures were differently oriented, these showed lattice mismatch at their junctions. This lattice mismatch though restricted complete shelling but successfully favored the secondary growth on specific facets of parent CsPbBr3 nanocrystals. Details of this secondary growth via lattice extension and expansion are microscopically analyzed and reported. These results further suggest that lead halide perovskite nanocrystals can be epitaxially grown under proper reaction design and more complex as well as heterostructures of these materials can be fabricated to meet the current demands.
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Affiliation(s)
- Sumit Kumar Dutta
- School of Materials Sciences, Indian Association for the Cultivation of Sciences, Kolkata 700032, India
| | - Suman Bera
- School of Materials Sciences, Indian Association for the Cultivation of Sciences, Kolkata 700032, India
| | - Rakesh Kumar Behera
- School of Materials Sciences, Indian Association for the Cultivation of Sciences, Kolkata 700032, India
| | - Biswajit Hudait
- School of Materials Sciences, Indian Association for the Cultivation of Sciences, Kolkata 700032, India
| | - Narayan Pradhan
- School of Materials Sciences, Indian Association for the Cultivation of Sciences, Kolkata 700032, India
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Bera S, Shyamal S, Pradhan N. Chemically Spiraling CsPbBr 3 Perovskite Nanorods. J Am Chem Soc 2021; 143:14895-14906. [PMID: 34469686 DOI: 10.1021/jacs.1c07231] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Light emitting lead halide perovskite nanocrystals are currently emerging as the workhorse in quantum dot research. Most of these reported nanocrystals are isotropic cubes or polyhedral; but anisotropic nanostructures with controlled anisotropic directions still remain a major challenge. For orthorhombic CsPbBr3, the 1D shaped nanostructures reported are linear and along either of the axial directions ⟨100⟩. In contrast, herein, spiral CsPbBr3 perovskite nanorods in the orthorhombic phase are reported with unusual anisotropy having (101) planes remaining perpendicular to the major axis [201]. While these nanorods are synthesized using the prelattice of orthorhombic Cs2CdBr4 with Pb(II) diffusion, the spirality is controlled by manipulation of the compositions of alkylammonium ions in the reaction system which selectively dissolve some spiral facets of the nanorods. Further, as spirality varied with facet creation and elimination, these nanorods were explored as photocatalysts for CO2 reduction, and the evolution of methane was also found to be dependent on the depth of the spiral nanorods. The entire study demonstrates facet manipulation of complex nanorods, and these results suggest that even if perovskites are ionic in nature, their shape could be constructed by design with proper reaction manipulation.
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Affiliation(s)
- Suman Bera
- School of Materials Sciences, Indian Association for the Cultivation of Science, Kolkata 700032, India
| | - Sanjib Shyamal
- School of Materials Sciences, Indian Association for the Cultivation of Science, Kolkata 700032, India
| | - Narayan Pradhan
- School of Materials Sciences, Indian Association for the Cultivation of Science, Kolkata 700032, India
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