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Zhu X, Zhang S, Ye S. Does Mn 2+-Mn 2+ Spin-Exchange Interaction Involve Mn 2+ Luminescence of Mn 2+-Doped/Concentrated Materials? J Phys Chem Lett 2024:2804-2814. [PMID: 38440997 DOI: 10.1021/acs.jpclett.3c03581] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/06/2024]
Abstract
Mn2+-doped luminescent quantum dots play a vital role in the fields of optoelectronic materials and devices. The presence of five unpaired d electrons in Mn2+ ions facilitates spin-exchange interactions, profoundly influencing the spin state of the exciton and thereby impacting the optical behaviors. However, the involvement and specific effects of spin-exchange interactions on optical properties of Mn2+ in insulating bulk phosphors remain a subject of controversy, attributed to the scarcity of solid evidence and the interference of various factors. In this Perspective, we delve into the fundamentals and recent advancements concerning the Mn2+-Mn2+ spin-exchange interaction in Mn2+ luminescent materials. The discussion encompasses various aspects, such as types of magnetic coupling, the coupling mechanism in optical ground state and excited state, as well as effective measures for verification. This Perspective underscores the existing knowledge gaps in Mn2+-doped bulk phosphors, highlighting significant opportunities for further exploration and advancement in both fundamental and applied research within this domain.
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Affiliation(s)
- Xinglu Zhu
- State Key Laboratory of Luminescent Materials and Devices, and Guangdong Provincial Key Laboratory of Fiber Laser Materials and Applied Techniques, School of Materials Science and Engineering, South China University of Technology, Guangzhou 510641, China
| | - Shuai Zhang
- State Key Laboratory of Luminescent Materials and Devices, and Guangdong Provincial Key Laboratory of Fiber Laser Materials and Applied Techniques, School of Materials Science and Engineering, South China University of Technology, Guangzhou 510641, China
| | - Shi Ye
- State Key Laboratory of Luminescent Materials and Devices, and Guangdong Provincial Key Laboratory of Fiber Laser Materials and Applied Techniques, School of Materials Science and Engineering, South China University of Technology, Guangzhou 510641, China
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2
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Mondal P, Sathiyamani S, Das S, Viswanatha R. Electronic structure study of dual-doped II-VI semiconductor quantum dots towards single-source white light emission. NANOSCALE 2023; 15:15288-15297. [PMID: 37681636 DOI: 10.1039/d3nr03542e] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/09/2023]
Abstract
Single-source white light emitting colloidal semiconductor quantum dots (QDs) is one of the most exciting and promising high-quality solid-state light sources to meet the current global demand for sustainable resources. While most of the previous methods involve dual (green-red) emissive nanostructures coated on blue LEDs to achieve white light, this work describes a single-source white light emitter of robust and superior quality using dual-doping. A modified synthesis method for intense white light emitting Cu, Mn dual-doped ZnSe QDs is engineered such that the extent of doping and concentration of ligands can alter their electronic structures. This is then customized to obtain various types of white light emissions ranging from warm white to cool white. Further, the composition-driven change in the electronic structure of the host QDs is exploited to achieve emission tunability over the entire visible range.
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Affiliation(s)
- Payel Mondal
- New Chemistry Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bangalore 560064, India.
| | - Sowmeya Sathiyamani
- New Chemistry Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bangalore 560064, India.
| | - Subham Das
- New Chemistry Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bangalore 560064, India.
| | - Ranjani Viswanatha
- New Chemistry Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bangalore 560064, India.
- International Centre for Materials Science, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bangalore 560064, India
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3
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Nadtochenko V, Cherepanov D, Kochev S, Motyakin M, Kostrov A, Golub A, Antonova O, Kabachii Y, Rtimi S. Structural and optical properties of Mn2+-doped ZnCdS/ZnS core/shell quantum dots: New insights in Mn2+ localization for higher luminescence sensing. J Photochem Photobiol A Chem 2022. [DOI: 10.1016/j.jphotochem.2022.113946] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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4
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Mondal P, Viswanatha R. Insights into the Oxidation State of Cu Dopants in II-VI Semiconductor Nanocrystals. J Phys Chem Lett 2022; 13:1952-1961. [PMID: 35188398 DOI: 10.1021/acs.jpclett.1c04076] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Luminescent Cu-doped semiconductor nanocrystals have played a pivotal role in the emergence of lighting and display applications for a long time. However, consensus regarding the Cu oxidation state and hence their emission mechanism has not been attained. Distinction between seemingly simple optically and magnetically active Cu2+ and inactive Cu1+ has surprisingly been the subject matter of debate in the literature for more than a decade. In this Perspective, we first discuss the fundamental quantum mechanical phenomenon explaining the optical properties of the monovalent and divalent Cu dopants. We then focus down on various techniques used to differentiate between these two fundamental mechanisms, their benefits, and their pitfalls arising in large part because of the lack of spatial separation. Hence, to obtain a cohesive story consistent with all the observations, we discuss recent results from single-molecule spectroscopy to understand the optical properties and hence the oxidation state of internally doped Cu in doped nanocrystals.
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5
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Torma AJ, Li W, Zhang H, Tu Q, Klepov VV, Brennan MC, McCleese CL, Krzyaniak MD, Wasielewski MR, Katan C, Even J, Holt MV, Grusenmeyer TA, Jiang J, Pachter R, Kanatzidis MG, Blancon JC, Mohite AD. Interstitial Nature of Mn 2+ Doping in 2D Perovskites. ACS NANO 2021; 15:20550-20561. [PMID: 34882393 DOI: 10.1021/acsnano.1c09142] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Halide perovskites doped with magnetic impurities (such as the transition metals Mn2+, Co2+, Ni2+) are being explored for a wide range of applications beyond photovoltaics, such as spintronic devices, stable light-emitting diodes, single-photon emitters, and magneto-optical devices. However, despite several recent studies, there is no consensus on whether the doped magnetic ions will predominantly replace the octahedral B-site metal via substitution or reside at interstitial defect sites. Here, by performing correlated nanoscale X-ray microscopy, spatially and temporally resolved photoluminescence measurements, and magnetic force microscopy on the inorganic 2D perovskite Cs2PbI2Cl2, we show that doping Mn2+ into the structure results in a lattice expansion. The observed lattice expansion contrasts with the predicted contraction expected to arise from the B-site metal substitution, thus implying that Mn2+ does not replace the Pb2+ sites. Photoluminescence and electron paramagnetic resonance measurements confirm the presence of Mn2+ in the lattice, while correlated nano-XRD and X-ray fluorescence track the local strain and chemical composition. Density functional theory calculations predict that Mn2+ atoms reside at the interstitial sites between two octahedra in the triangle formed by one Cl- and two I- atoms, which results in a locally expanded structure. These measurements show the fate of the transition metal dopants, the local structure, and optical emission when they are doped at dilute concentrations into a wide band gap semiconductor.
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Affiliation(s)
- Andrew J Torma
- Department of Chemical and Biomolecular Engineering, Rice University, Houston, Texas 77005, United States
- Applied Physics Program, Smalley-Curl Institute, Rice University, Houston, Texas 77005, United States
| | - Wenbin Li
- Department of Chemical and Biomolecular Engineering, Rice University, Houston, Texas 77005, United States
- Applied Physics Program, Smalley-Curl Institute, Rice University, Houston, Texas 77005, United States
| | - Hao Zhang
- Department of Chemical and Biomolecular Engineering, Rice University, Houston, Texas 77005, United States
- Applied Physics Program, Smalley-Curl Institute, Rice University, Houston, Texas 77005, United States
| | - Qing Tu
- Department of Materials Science and Engineering, Texas A&M University, College Station, Texas 77843, United States
| | - Vladislav V Klepov
- Department of Chemistry and Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois 60208, United States
| | - Michael C Brennan
- Air Force Research Laboratory, Materials and Manufacturing Directorate, Wright-Patterson Air Force Base, Dayton, Ohio 45433, United States
| | - Christopher L McCleese
- Air Force Research Laboratory, Materials and Manufacturing Directorate, Wright-Patterson Air Force Base, Dayton, Ohio 45433, United States
- General Dynamics Information Technology, 5000 Springfield Pike, Dayton, Ohio 45431, United States
| | - Matthew D Krzyaniak
- Department of Chemistry and Institute for Sustainability and Energy at Northwestern, Northwestern University, Evanston, Illinois 60208-3113, United States
| | - Michael R Wasielewski
- Department of Chemistry and Institute for Sustainability and Energy at Northwestern, Northwestern University, Evanston, Illinois 60208-3113, United States
| | - Claudine Katan
- Univ Rennes, ENSCR, INSA Rennes, CNRS, ISCR (Institut des Sciences Chimiques de Rennes)-UMR 6226, F-35000 Rennes, France
| | - Jacky Even
- Univ Rennes, INSA Rennes, CNRS, Institut FOTON-UMR 6082, F-35000 Rennes, France
| | - Martin V Holt
- Center for Nanoscale Materials, Argonne National Laboratory, Lemont, Illinois 60439, United States
| | - Tod A Grusenmeyer
- Air Force Research Laboratory, Materials and Manufacturing Directorate, Wright-Patterson Air Force Base, Dayton, Ohio 45433, United States
| | - Jie Jiang
- Air Force Research Laboratory, Materials and Manufacturing Directorate, Wright-Patterson Air Force Base, Dayton, Ohio 45433, United States
| | - Ruth Pachter
- Air Force Research Laboratory, Materials and Manufacturing Directorate, Wright-Patterson Air Force Base, Dayton, Ohio 45433, United States
| | - Mercouri G Kanatzidis
- Department of Chemistry and Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois 60208, United States
| | - Jean-Christophe Blancon
- Department of Chemical and Biomolecular Engineering, Rice University, Houston, Texas 77005, United States
| | - Aditya D Mohite
- Department of Chemical and Biomolecular Engineering, Rice University, Houston, Texas 77005, United States
- Applied Physics Program, Smalley-Curl Institute, Rice University, Houston, Texas 77005, United States
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6
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Ultrafast Quenching of Excitons in the Zn xCd 1-xS/ZnS Quantum Dots Doped with Mn 2+ through Charge Transfer Intermediates Results in Manganese Luminescence. NANOMATERIALS 2021; 11:nano11113007. [PMID: 34835771 PMCID: PMC8618633 DOI: 10.3390/nano11113007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/07/2021] [Revised: 10/27/2021] [Accepted: 11/03/2021] [Indexed: 11/17/2022]
Abstract
For the first time, a specific time-delayed peak was registered in the femtosecond transient absorption (TA) spectra of ZnxCd1−xS/ZnS (x~0.5) alloy quantum dots (QDs) doped with Mn2+, which was interpreted as the electrochromic Stark shift of the band-edge exciton. The time-delayed rise and decay kinetics of the Stark peak in the manganese-doped QDs significantly distinguish it from the kinetics of the Stark peak caused by exciton–exciton interaction in the undoped QDs. The Stark shift in the Mn2+-doped QDs developed at a 1 ps time delay in contrast to the instantaneous appearance of the Stark shift in the undoped QDs. Simultaneously with the development of the Stark peak in the Mn2+-doped QDs, stimulated emission corresponding to 4T1-6A1 Mn2+ transition was detected in the subpicosecond time domain. The time-delayed Stark peak in the Mn2+-doped QDs, associated with the development of an electric field in QDs, indicates the appearance of charge transfer intermediates in the process of exciton quenching by manganese ions, leading to the ultrafast Mn2+ excitation. The usually considered mechanism of the nonradiative energy transfer from an exciton to Mn2+ does not imply the development of an electric field in a QD. Femtosecond TA data were analyzed using a combination of empirical and computational methods. A kinetic scheme of charge transfer processes is proposed to explain the excitation of Mn2+. The kinetic scheme includes the reduction of Mn2+ by a 1Se electron and the subsequent oxidation of Mn1+ with a hole, leading to the formation of an excited state of manganese.
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7
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Temperature-dependent anomalous Mn2+ emission and excited state dynamics in Mn2+-doped MAPbCl3-xBrx nanocrystals. J CHEM SCI 2021. [DOI: 10.1007/s12039-021-01919-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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8
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Najafi A, Sharma M, Delikanli S, Bhattacharya A, Murphy JR, Pientka J, Sharma A, Quinn AP, Erdem O, Kattel S, Kelestemur Y, Kovalenko MV, Rice WD, Demir HV, Petrou A. Light-Induced Paramagnetism in Colloidal Ag +-Doped CdSe Nanoplatelets. J Phys Chem Lett 2021; 12:2892-2899. [PMID: 33724845 DOI: 10.1021/acs.jpclett.1c00398] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
We describe a study of the magneto-optical properties of Ag+-doped CdSe colloidal nanoplatelets (NPLs) that were grown using a novel doping technique. In this work, we used magnetic circularly polarized luminescence and magnetic circular dichroism spectroscopy to study light-induced magnetism for the first time in 2D solution-processed structures doped with nominally nonmagnetic Ag+ impurities. The excitonic circular polarization (PX) and the exciton Zeeman splitting (ΔEZ) were recorded as a function of the magnetic field (B) and temperature (T). Both ΔEZ and PX have a Brillouin-function-like dependence on B and T, verifying the presence of paramagnetism in Ag+-doped CdSe NPLs. The observed light-induced magnetism is attributed to the transformation of nonmagnetic Ag+ ions into Ag2+, which have a nonzero magnetic moment. This work points to the possibility of incorporating these nanoplatelets into spintronic devices, in which light can be used to control the spin injection.
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Affiliation(s)
- Arman Najafi
- Department of Physics, University at Buffalo SUNY, Buffalo, New York 14260, United States
| | - Manoj Sharma
- Luminous! Centre of Excellence for Semiconductor Lighting and Displays, School of Electrical and Electronic Engineering and Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 639798
- Department of Electrical and Electronics Engineering and Department of Physics, UNAM-Institute of Materials Science and Nanotechnology, Bilkent University, 06800 Ankara, Turkey
| | - Savas Delikanli
- Luminous! Centre of Excellence for Semiconductor Lighting and Displays, School of Electrical and Electronic Engineering and Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 639798
- Department of Electrical and Electronics Engineering and Department of Physics, UNAM-Institute of Materials Science and Nanotechnology, Bilkent University, 06800 Ankara, Turkey
| | - Arinjoy Bhattacharya
- Department of Physics, University at Buffalo SUNY, Buffalo, New York 14260, United States
| | - Joseph R Murphy
- Department of Chemistry and Physics, Southeast Missouri State University, Cape Girardeau, Missouri 63701, United States
- Department of Physics and Astronomy, University of Wyoming, Laramie, Wyoming 82071, United States
| | - James Pientka
- Department of Physics, St. Bonaventure University, St. Bonaventure, New York 14778, United States
| | - Ashma Sharma
- Luminous! Centre of Excellence for Semiconductor Lighting and Displays, School of Electrical and Electronic Engineering and Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 639798
| | - Alexander P Quinn
- Department of Physics, University at Buffalo SUNY, Buffalo, New York 14260, United States
| | - Onur Erdem
- Department of Electrical and Electronics Engineering and Department of Physics, UNAM-Institute of Materials Science and Nanotechnology, Bilkent University, 06800 Ankara, Turkey
| | - Subash Kattel
- Department of Physics and Astronomy, University of Wyoming, Laramie, Wyoming 82071, United States
| | - Yusuf Kelestemur
- Department of Chemistry and Applied Biosciences, ETH Zürich, Vladimir Prelog Weg 1, CH-8093 Zürich, Switzerland
- Department of Metallurgical and Materials Engineering, Atilim University, Ankara 06830, Turkey
| | - Maksym V Kovalenko
- Department of Chemistry and Applied Biosciences, ETH Zürich, Vladimir Prelog Weg 1, CH-8093 Zürich, Switzerland
- Empa-Swiss Federal Laboratories for Materials Science and Technology, Überlandstrasse 129, CH-8600 Dübendorf, Switzerland
| | - William D Rice
- Department of Physics and Astronomy, University of Wyoming, Laramie, Wyoming 82071, United States
| | - Hilmi Volkan Demir
- Luminous! Centre of Excellence for Semiconductor Lighting and Displays, School of Electrical and Electronic Engineering and Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 639798
- Department of Electrical and Electronics Engineering and Department of Physics, UNAM-Institute of Materials Science and Nanotechnology, Bilkent University, 06800 Ankara, Turkey
| | - Athos Petrou
- Department of Physics, University at Buffalo SUNY, Buffalo, New York 14260, United States
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9
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Sarang S, Delmas W, Bonabi Naghadeh S, Cherrette V, Zhang JZ, Ghosh S. Low-Temperature Energy Transfer via Self-Trapped Excitons in Mn 2+-Doped 2D Organometal Halide Perovskites. J Phys Chem Lett 2020; 11:10368-10374. [PMID: 33236909 DOI: 10.1021/acs.jpclett.0c03287] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
We investigate the mechanisms of energy transfer in Mn2+-doped ethylammonium lead bromide (EA2PbBr4:Mn2+), a two-dimensional layered perovskite (2DLP), using cryogenic optical spectroscopy. At temperature T > 120 K, photoluminescence (PL) is dominated by emission from Mn2+, with complete suppression of band edge (BE) emission and self-trapped exciton (STE) emission. However, for T < 120 K, in addition to Mn2+ emission, PL is observed from BE and STEs. Data further reveal that for 20 K < T < 120 K, STEs form the most dominant routes in assisting energy transfer (ET) from 2DLP to Mn2+ dopants. However, at higher Mn2+ concentration, higher activation energies indicate defect states come into play, successfully competing with STEs for ET both from BE to STE states and from STE to Mn2+. Finally, using polarization-resolved spectroscopy, we demonstrate optical spin orientation of the Mn2+ ions via ET from 2DLP excitons at zero magnetic field. Our results reveal fundamental insights on the interactions between quantum confined charge carriers and dopants in organometal halide perovskites.
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Affiliation(s)
- Som Sarang
- Department of Physics, School of Natural Sciences, University of California, Merced, California 95343, United States
| | - William Delmas
- Department of Physics, School of Natural Sciences, University of California, Merced, California 95343, United States
| | - Sara Bonabi Naghadeh
- Department of Chemistry and Biochemistry, University of California, Santa Cruz, California 95064, United States
| | - Vivien Cherrette
- Department of Chemistry and Biochemistry, University of California, Santa Cruz, California 95064, United States
| | - Jin Z Zhang
- Department of Chemistry and Biochemistry, University of California, Santa Cruz, California 95064, United States
| | - Sayantani Ghosh
- Department of Physics, School of Natural Sciences, University of California, Merced, California 95343, United States
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10
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Fang Z, Peng W, Zheng S, Qiu J, Guan BO. Controllable modulation of coordination environments of Mn2+ in glasses and glass-ceramics for tunable luminescence. Ann Ital Chir 2020. [DOI: 10.1016/j.jeurceramsoc.2019.12.025] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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11
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Chen W, Tang X, Zang Z, Shi Y, Yang Z, Du J. Tunable dual emission in Mn 2+-doped CsPbX 3 (X = Cl, Br) quantum dots for high efficiency white light-emitting diodes. NANOTECHNOLOGY 2019; 30:075704. [PMID: 30524095 DOI: 10.1088/1361-6528/aaf299] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Doping of Mn2+ into semiconductor nanocrystals has been demonstrated to endow them with novel electronic, optical and magnetic functionalities. In this paper, Mn-doped CsPbX3 (X = Br, Cl) quantum dots (QDs) were synthesized at room temperature via a facile strategy by introducing dimethyl sulfoxide (DMSO)-MnBr2/PbX2 composite as a precursor. The excitonic emission spectra of the as-obtained Mn-doped CsPbX3 QDs can be tuned from 517 nm to 418 nm by adjusting the ratio of PbBr2/PbCl2 precisely, and the luminescence mechanism of the doped QDs is discussed in detail. Moreover, the highest photoluminescence quantum yield of the Mn2+ emission achieves 36.7%, which is comparable with QDs prepared by the conventional hot-injection method. Depending on the ratios of PbPb2/PbCl2, the energy transfer rate from the band-edge to Mn2+ excited state is in the range of 0.006-20.42 × 107 s-1. Furthermore, white light-emitting diodes (LEDs) were successfully fabricated by combining the as-prepared Mn-doped CsPbX3 QDs with commercial UV GaN chips, and the high luminous efficiency of the as-prepared white LEDs was developed to 55.9 lm W-1. This work strongly supports the fact that Mn-doped CsPbX3 QDs are promising materials for application in lighting and displaying fields.
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Affiliation(s)
- Weiwei Chen
- Key Laboratory of Optoelectronic Technology & Systems, Ministry of Education, Chongqing University, Chongqing 400044, People's Republic of China
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12
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Halder O, Satpati B, Rajput P, Mohapatra N, Jha SN, Suffczyński J, Pacuski W, Rath S. Light Emitting Spin Active Electronic States in Ultra-Thin Mn Doped CdSe Layered Nanosheets. Sci Rep 2019; 9:1804. [PMID: 30755677 PMCID: PMC6372604 DOI: 10.1038/s41598-019-38974-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2018] [Accepted: 12/27/2018] [Indexed: 11/17/2022] Open
Abstract
The layered nanosheets exhibit a variety of physical and optical properties originating from amalgamation of intra- and inter- layer electronic interactions, which makes them promising materials for advanced devices with varsatile controlling channels. In particular, the dilute magnetic semiconductor multilayered nanosheets have promising optical, electrical and magnetic properties that have been less explored so far. Here, the spin permissible optical properties from solvothermally grown Mn doped CdSe (thickness ~2.26 nm) multilayered nanosheets are reported on. The presence of multi-phase magnetic orderings with a sharp ferromagnetic transition at temperature ~48 K pertinent to the stabilization and co-existence of Mn2+ and Mn3+ based local phases have been observed from the (Cd,Mn)Se layered nanosheets corroborating to the x-ray absorption near edge structure, electron paramagnetic resonance, Raman scattering and magnetic measurements. The optical absorption and photoluminescence (PL) studies at room temperature affirm wide array of optical properties in the visible regime corresponding to the band edge and intriguing dopant-phase mediated spin approved transitions. The circularly polarized magneto-PL and life time analysis exhibits the spin-polarized fast radiative transitions confirming the presence of spin-active electronic states.
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Affiliation(s)
- O Halder
- School of Basic Sciences, Indian Institute of Technology Bhubaneswar, Jatni, 752 050, Khurda, India
| | - B Satpati
- Saha Institute of Nuclear Physics, 1/AF Bidhannagar, Kolkata, 700 064, India
| | - P Rajput
- Atomic & Molecular Physics Division, Bhabha Atomic Research Centre, Trombay, Mumbai, 400085, India
| | - N Mohapatra
- School of Basic Sciences, Indian Institute of Technology Bhubaneswar, Jatni, 752 050, Khurda, India
| | - S N Jha
- Atomic & Molecular Physics Division, Bhabha Atomic Research Centre, Trombay, Mumbai, 400085, India
| | - J Suffczyński
- Institute of Experimental Physics, Faculty of Physics, University of Warsaw, Pasteura 5 St., Warsaw, 02-093, Poland
| | - W Pacuski
- Institute of Experimental Physics, Faculty of Physics, University of Warsaw, Pasteura 5 St., Warsaw, 02-093, Poland
| | - S Rath
- School of Basic Sciences, Indian Institute of Technology Bhubaneswar, Jatni, 752 050, Khurda, India.
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Smith MD, Connor BA, Karunadasa HI. Tuning the Luminescence of Layered Halide Perovskites. Chem Rev 2019; 119:3104-3139. [DOI: 10.1021/acs.chemrev.8b00477] [Citation(s) in RCA: 379] [Impact Index Per Article: 75.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Matthew D. Smith
- Department of Chemistry, Stanford University, Stanford, California 94305, United States
| | - Bridget A. Connor
- Department of Chemistry, Stanford University, Stanford, California 94305, United States
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14
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Pietryga JM, Park YS, Lim J, Fidler AF, Bae WK, Brovelli S, Klimov VI. Spectroscopic and Device Aspects of Nanocrystal Quantum Dots. Chem Rev 2017; 116:10513-622. [PMID: 27677521 DOI: 10.1021/acs.chemrev.6b00169] [Citation(s) in RCA: 400] [Impact Index Per Article: 57.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The field of nanocrystal quantum dots (QDs) is already more than 30 years old, and yet continuing interest in these structures is driven by both the fascinating physics emerging from strong quantum confinement of electronic excitations, as well as a large number of prospective applications that could benefit from the tunable properties and amenability toward solution-based processing of these materials. The focus of this review is on recent advances in nanocrystal research related to applications of QD materials in lasing, light-emitting diodes (LEDs), and solar energy conversion. A specific underlying theme is innovative concepts for tuning the properties of QDs beyond what is possible via traditional size manipulation, particularly through heterostructuring. Examples of such advanced control of nanocrystal functionalities include the following: interface engineering for suppressing Auger recombination in the context of QD LEDs and lasers; Stokes-shift engineering for applications in large-area luminescent solar concentrators; and control of intraband relaxation for enhanced carrier multiplication in advanced QD photovoltaics. We examine the considerable recent progress on these multiple fronts of nanocrystal research, which has resulted in the first commercialized QD technologies. These successes explain the continuing appeal of this field to a broad community of scientists and engineers, which in turn ensures even more exciting results to come from future exploration of this fascinating class of materials.
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Affiliation(s)
- Jeffrey M Pietryga
- Nanotechnology and Advanced Spectroscopy Team, Chemistry Division, Los Alamos National Laboratory , Los Alamos, New Mexico 87545, United States
| | - Young-Shin Park
- Nanotechnology and Advanced Spectroscopy Team, Chemistry Division, Los Alamos National Laboratory , Los Alamos, New Mexico 87545, United States.,Center for High Technology Materials, University of New Mexico , Albuquerque, New Mexico 87131, United States
| | - Jaehoon Lim
- Nanotechnology and Advanced Spectroscopy Team, Chemistry Division, Los Alamos National Laboratory , Los Alamos, New Mexico 87545, United States
| | - Andrew F Fidler
- Nanotechnology and Advanced Spectroscopy Team, Chemistry Division, Los Alamos National Laboratory , Los Alamos, New Mexico 87545, United States
| | - Wan Ki Bae
- Photo-Electronic Hybrids Research Center, Korea Institute of Science and Technology , Seoul 02792, Korea
| | - Sergio Brovelli
- Dipartimento di Scienza dei Materiali, Università degli Studi di Milano-Bicocca , I-20125 Milano, Italy
| | - Victor I Klimov
- Nanotechnology and Advanced Spectroscopy Team, Chemistry Division, Los Alamos National Laboratory , Los Alamos, New Mexico 87545, United States
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15
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Saha A, Makkar M, Shetty A, Gahlot K, A R P, Viswanatha R. Diffusion doping in quantum dots: bond strength and diffusivity. NANOSCALE 2017; 9:2806-2813. [PMID: 28155949 DOI: 10.1039/c6nr09839h] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Semiconducting materials uniformly doped with optical or magnetic impurities have been useful in a number of potential applications. However, clustering or phase separation during synthesis has made this job challenging. Recently the "inside out" diffusion doping was proposed to be successful in obtaining large sized quantum dots (QDs) uniformly doped with a dilute percentage of dopant atoms. Herein, we demonstrate the use of basic physical chemistry of diffusion to control the size and concentration of the dopants within the QDs for a given transition metal ion. We have studied three parameters; the bond strength of the core molecules and the diffusion coefficient of the diffusing metal ion are found to be important while the ease of cation exchange was not highly influential in the control of size and concentration of the single domain dilute magnetic semiconductor quantum dots (DMSQDs) with diverse dopant ions M2+ (Fe2+, Ni2+, Co2+, Mn2+). Steady state optical emission spectra reveal that the dopants are incorporated inside the semiconducting CdS and the emission can be tuned during shell growth. We have shown that this method enables control over doping percentage and the QDs show a superior ferromagnetic response at room temperature as compared to previously reported systems.
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Affiliation(s)
- Avijit Saha
- New Chemistry Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bangalore 560064, India.
| | - Mahima Makkar
- New Chemistry Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bangalore 560064, India.
| | - Amitha Shetty
- International Centre for Materials Science, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bangalore 560064, India
| | - Kushagra Gahlot
- New Chemistry Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bangalore 560064, India.
| | - Pavan A R
- International Centre for Materials Science, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bangalore 560064, India
| | - Ranjani Viswanatha
- New Chemistry Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bangalore 560064, India. and International Centre for Materials Science, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bangalore 560064, India
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16
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Pandey A, Sarma DD. Recent Advances in Manganese Doped II-VI Semiconductor Quantum Dots. Z Anorg Allg Chem 2016. [DOI: 10.1002/zaac.201600368] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Anshu Pandey
- Solid State and Structural Chemistry Unit; Indian Institute of Science; 560012 Bangalore India
| | - Dipankar Das Sarma
- Solid State and Structural Chemistry Unit; Indian Institute of Science; 560012 Bangalore India
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17
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Liu W, Lin Q, Li H, Wu K, Robel I, Pietryga JM, Klimov VI. Mn 2+-Doped Lead Halide Perovskite Nanocrystals with Dual-Color Emission Controlled by Halide Content. J Am Chem Soc 2016; 138:14954-14961. [PMID: 27756131 DOI: 10.1021/jacs.6b08085] [Citation(s) in RCA: 319] [Impact Index Per Article: 39.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Impurity doping has been widely used to endow semiconductor nanocrystals with novel optical, electronic, and magnetic functionalities. Here, we introduce a new family of doped NCs offering unique insights into the chemical mechanism of doping, as well as into the fundamental interactions between the dopant and the semiconductor host. Specifically, by elucidating the role of relative bond strengths within the precursor and the host lattice, we develop an effective approach for incorporating manganese (Mn) ions into nanocrystals of lead-halide perovskites (CsPbX3, where X = Cl, Br, or I). In a key enabling step not possible in, for example, II-VI nanocrystals, we use gentle chemical means to finely and reversibly tune the nanocrystal band gap over a wide range of energies (1.8-3.1 eV) via postsynthetic anion exchange. We observe a dramatic effect of halide identity on relative intensities of intrinsic band-edge and Mn emission bands, which we ascribe to the influence of the energy difference between the corresponding transitions on the characteristics of energy transfer between the Mn ion and the semiconductor host.
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Affiliation(s)
- Wenyong Liu
- Chemistry Division, Los Alamos National Laboratory , Los Alamos, New Mexico 87545, United States
| | - Qianglu Lin
- Chemistry Division, Los Alamos National Laboratory , Los Alamos, New Mexico 87545, United States
| | - Hongbo Li
- Chemistry Division, Los Alamos National Laboratory , Los Alamos, New Mexico 87545, United States
| | - Kaifeng Wu
- Chemistry Division, Los Alamos National Laboratory , Los Alamos, New Mexico 87545, United States
| | - István Robel
- Chemistry Division, Los Alamos National Laboratory , Los Alamos, New Mexico 87545, United States
| | - Jeffrey M Pietryga
- Chemistry Division, Los Alamos National Laboratory , Los Alamos, New Mexico 87545, United States
| | - Victor I Klimov
- Chemistry Division, Los Alamos National Laboratory , Los Alamos, New Mexico 87545, United States
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18
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Saha A, Shetty A, Pavan AR, Chattopadhyay S, Shibata T, Viswanatha R. Uniform Doping in Quantum-Dots-Based Dilute Magnetic Semiconductor. J Phys Chem Lett 2016; 7:2420-2428. [PMID: 27295453 DOI: 10.1021/acs.jpclett.6b01099] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Effective manipulation of magnetic spin within a semiconductor leading to a search for ferromagnets with semiconducting properties has evolved into an important field of dilute magnetic semiconductors (DMS). Although a lot of research is focused on understanding the still controversial origin of magnetism, efforts are also underway to develop new materials with higher magnetic temperatures for spintronics applications. However, so far, efforts toward quantum-dots(QDs)-based DMS materials are plagued with problems of phase separation, leading to nonuniform distribution of dopant ions. In this work, we have developed a strategy to synthesize highly crystalline, single-domain DMS system starting from a small magnetic core and allowing it to diffuse uniformly inside a thick CdS semiconductor matrix and achieve DMS QDs. X-ray absorption fine structure (XAFS) spectroscopy and energy-dispersive X-ray spectroscopy-scanning transmission electron microscopy (STEM-EDX) indicates the homogeneous distribution of magnetic impurities inside the semiconductor QDs leading to superior magnetic property. Further, the versatility of this technique was demonstrated by obtaining ultra large particles (∼60 nm) with uniform doping concentration as well as demonstrating the high quality magnetic response.
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Affiliation(s)
| | | | | | - Soma Chattopadhyay
- Sector 10 ID, CSRRI-IIT, Advanced Photon Source, 9700 South Cass Avenue, Lemont, Illinois 60439, United States
- Advanced Materials Group, Physics Department, Illinois Institute of Technology , Chicago, Illinois 60616, United States
| | - Tomohiro Shibata
- MRCAT, Argonne National Laboratory , Argonne, Illinois 60439, United States
- Advanced Materials Group, Physics Department, Illinois Institute of Technology , Chicago, Illinois 60616, United States
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19
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Pradhan N. Red-Tuned Mn d-d Emission in Doped Semiconductor Nanocrystals. Chemphyschem 2016; 17:1087-94. [PMID: 26632423 DOI: 10.1002/cphc.201500953] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2015] [Indexed: 12/30/2022]
Abstract
Light-emitting Mn-doped semiconductor nanocrystals have been extensively studied for the last three decades for their intense and stable Mn d-d emission. In principle, this emission should be fixed at 585 nm (yellow), but recent studies have shown that the emission can be widely tuned even to 650 nm (red). This is a spectacular achievement as this would make Mn-doped nanocrystals efficient and tunable light emitters. Keeping these developments in view, the chemistry of the synthesis of these materials, their photophysical processes and the expected origins of their red emission are summarized in this Minireview. All the related important studies from 1992 onwards are chronologically discussed, and one particular case is elaborated on in detail. As these materials are potentially important for biology, and photovoltaic, sensing and light-emitting devices, this Minireview is expected to help researchers investigating the chemistry, physics and applications of these materials.
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Affiliation(s)
- Narayan Pradhan
- Department of Materials Science, Indian Association for the Cultivation of Science, Kolkata, 700032, India.
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20
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Hartmann NF, Yalcin SE, Adamska L, Hároz EH, Ma X, Tretiak S, Htoon H, Doorn SK. Photoluminescence imaging of solitary dopant sites in covalently doped single-wall carbon nanotubes. NANOSCALE 2015; 7:20521-20530. [PMID: 26586162 DOI: 10.1039/c5nr06343d] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Covalent dopants in semiconducting single wall carbon nanotubes (SWCNTs) are becoming important as routes for introducing new photoluminescent emitting states with potential for enhanced quantum yields, new functionality, and as species capable of near-IR room-temperature single photon emission. The origin and behavior of the dopant-induced emission is thus important to understand as a key requirement for successful room-T photonics and optoelectronics applications. Here, we use direct correlated two-color photoluminescence imaging to probe how the interplay between the SWCNT bright E(11) exciton and solitary dopant sites yields the dopant-induced emission for three different dopant species: oxygen, 4-methoxybenzene, and 4-bromobenzene. We introduce a route to control dopant functionalization to a low level as a means for introducing spatially well-separated solitary dopant sites. Resolution of emission from solitary dopant sites and correlation to their impact on E(11) emission allows confirmation of dopants as trapping sites for localization of E(11) excitons following their diffusive transport to the dopant site. Imaging of the dopant emission also reveals photoluminescence intermittency (blinking), with blinking dynamics being dependent on the specific dopant. Density functional theory calculations were performed to evaluate the stability of dopants and delineate the possible mechanisms of blinking. Theoretical modeling suggests that the trapping of free charges in the potential well created by permanent dipoles introduced by dopant atoms/groups is likely responsible for the blinking, with the strongest effects being predicted and observed for oxygen-doped SWCNTs.
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Affiliation(s)
- Nicolai F Hartmann
- Center for Integrated Nanotechnologies, Materials Physics and Applications Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.
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21
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Rodina A, Efros AL. Magnetic Properties of Nonmagnetic Nanostructures: Dangling Bond Magnetic Polaron in CdSe Nanocrystals. NANO LETTERS 2015; 15:4214-4222. [PMID: 25919576 DOI: 10.1021/acs.nanolett.5b01566] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
We predict theoretically that nonmagnetic CdSe nanocrystals may possess macroscopic magnetic moments due to the formation of dangling-bond magnetic polarons (DBMPs). A DBMP is created in optically pumped nanocrystals by dynamic polarization of dangling bond spins (DBSs) at the nanocrystal surface during radiative recombination of the ground state "dark" exciton assisted by a spin-flip of the DBS. The formation of DBMPs suppresses the radiative recombination of the dark exciton and leads to a temperature-dependent contribution to the Stokes shift of the photoluminescence. This model consistently explains the experimentally observed low-temperature photoluminescence features of nonmagnetic CdSe nanocrystals as manifestations of their spin-related magnetic properties.
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Affiliation(s)
- Anna Rodina
- †Ioffe Physical-Technical Institute, Russian Academy of Sciences, 194021 St. Petersburg, Russia
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22
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Sun Z, Yang X, Wang C, Yao T, Cai L, Yan W, Jiang Y, Hu F, He J, Pan Z, Liu Q, Wei S. Graphene activating room-temperature ferromagnetic exchange in cobalt-doped ZnO dilute magnetic semiconductor quantum dots. ACS NANO 2014; 8:10589-10596. [PMID: 25222885 DOI: 10.1021/nn5040845] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Control over the magnetic interactions in dilute magnetic semiconductor quantum dots (DMSQDs) is a key issue to future development of nanometer-sized integrated "spintronic" devices. However, manipulating the magnetic coupling between impurity ions in DMSQDs remains a great challenge because of the intrinsic quantum confinement effects and self-purification of the quantum dots. Here, we propose a hybrid structure to achieve room-temperature ferromagnetic interactions in DMSQDs, via engineering the density and nature of the energy states at the Fermi level. This idea has been applied to Co-doped ZnO DMSQDs where the growth of a reduced graphene oxide shell around the Zn(0.98)Co(0.02)O core turns the magnetic interactions from paramagnetic to ferromagnetic at room temperature, due to the hybridization of 2p(z) orbitals of graphene and 3d obitals of Co(2+)-oxygen-vacancy complexes. This design may open up a kind of possibility for manipulating the magnetism of doped oxide nanostructures.
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Affiliation(s)
- Zhihu Sun
- National Synchrotron Radiation Laboratory, University of Science and Technology of China , Hefei, Anhui 230029, People's Republic of China
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23
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Turyanska L, Hill RJA, Makarovsky O, Moro F, Knott AN, Larkin OJ, Patanè A, Meaney A, Christianen PCM, Fay MW, Curry RJ. Tuneable paramagnetic susceptibility and exciton g-factor in Mn-doped PbS colloidal nanocrystals. NANOSCALE 2014; 6:8919-8925. [PMID: 24966016 DOI: 10.1039/c4nr02336f] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
We report on PbS colloidal nanocrystals that combine within one structure solubility in physiological solvents with near-infrared photoluminescence, and magnetic and optical properties tuneable by the controlled incorporation of magnetic impurities (Mn). We use high magnetic fields (B up to 30 T) to measure the magnetization of the nanocrystals in liquid and the strength of the sp-d exchange interaction between the exciton and the Mn-ions. With increasing Mn-content from 0.1% to 7%, the mass magnetic susceptibility increases at a rate of ∼ 10(-7) m(3) kg(-1) per Mn percentage; correspondingly, the exciton g-factor decreases from 0.47 to 0.10. The controlled modification of the paramagnetism, fluorescence and exciton g-factor of the nanocrystals is relevant to the implementation of these paramagnetic semiconductor nanocrystals in quantum technologies ranging from quantum information to magnetic resonance imaging.
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Affiliation(s)
- L Turyanska
- School of Physics and Astronomy, The University of Nottingham, Nottingham NG7 2RD, UK.
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24
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Lin J, Zhang Q, Wang L, Liu X, Yan W, Wu T, Bu X, Feng P. Atomically Precise Doping of Monomanganese Ion into Coreless Supertetrahedral Chalcogenide Nanocluster Inducing Unusual Red Shift in Mn2+ Emission. J Am Chem Soc 2014; 136:4769-79. [DOI: 10.1021/ja501288x] [Citation(s) in RCA: 132] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Jian Lin
- College
of Chemistry, Chemical Engineering and Materials Science, Soochow University, Jiangsu 215123, China
| | - Qian Zhang
- College
of Chemistry, Chemical Engineering and Materials Science, Soochow University, Jiangsu 215123, China
| | - Le Wang
- College
of Chemistry, Chemical Engineering and Materials Science, Soochow University, Jiangsu 215123, China
| | - Xiaochun Liu
- College
of Chemistry, Chemical Engineering and Materials Science, Soochow University, Jiangsu 215123, China
| | - Wenbo Yan
- College
of Chemistry, Chemical Engineering and Materials Science, Soochow University, Jiangsu 215123, China
| | - Tao Wu
- College
of Chemistry, Chemical Engineering and Materials Science, Soochow University, Jiangsu 215123, China
| | - Xianhui Bu
- Department
of Chemistry and Biochemistry, California State University, 1250
Bellflower Blvd., Long Beach, California 90840, United States
| | - Pingyun Feng
- Department
of Chemistry, University of California, Riverside, California 92521, United States
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25
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Yan W, Liu Q, Wang C, Yang X, Yao T, He J, Sun Z, Pan Z, Hu F, Wu Z, Xie Z, Wei S. Realizing Ferromagnetic Coupling in Diluted Magnetic Semiconductor Quantum Dots. J Am Chem Soc 2014; 136:1150-5. [DOI: 10.1021/ja411900w] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Wensheng Yan
- National Synchrotron Radiation
Laboratory, University of Science and Technology of China, Hefei, Anhui 230029, China
| | - Qinghua Liu
- National Synchrotron Radiation
Laboratory, University of Science and Technology of China, Hefei, Anhui 230029, China
| | - Chao Wang
- National Synchrotron Radiation
Laboratory, University of Science and Technology of China, Hefei, Anhui 230029, China
| | - Xiaoyu Yang
- National Synchrotron Radiation
Laboratory, University of Science and Technology of China, Hefei, Anhui 230029, China
| | - Tao Yao
- National Synchrotron Radiation
Laboratory, University of Science and Technology of China, Hefei, Anhui 230029, China
| | - Jingfu He
- National Synchrotron Radiation
Laboratory, University of Science and Technology of China, Hefei, Anhui 230029, China
| | - Zhihu Sun
- National Synchrotron Radiation
Laboratory, University of Science and Technology of China, Hefei, Anhui 230029, China
| | - Zhiyun Pan
- National Synchrotron Radiation
Laboratory, University of Science and Technology of China, Hefei, Anhui 230029, China
| | - Fengchun Hu
- National Synchrotron Radiation
Laboratory, University of Science and Technology of China, Hefei, Anhui 230029, China
| | - Ziyu Wu
- National Synchrotron Radiation
Laboratory, University of Science and Technology of China, Hefei, Anhui 230029, China
| | - Zhi Xie
- National Synchrotron Radiation
Laboratory, University of Science and Technology of China, Hefei, Anhui 230029, China
| | - Shiqiang Wei
- National Synchrotron Radiation
Laboratory, University of Science and Technology of China, Hefei, Anhui 230029, China
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26
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Hazarika A, Layek A, De S, Nag A, Debnath S, Mahadevan P, Chowdhury A, Sarma DD. Ultranarrow and widely tunable Mn2+-Induced photoluminescence from single Mn-doped nanocrystals of ZnS-CdS alloys. PHYSICAL REVIEW LETTERS 2013; 110:267401. [PMID: 23848921 DOI: 10.1103/physrevlett.110.267401] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/2012] [Revised: 02/22/2013] [Indexed: 06/02/2023]
Abstract
Extensively studied Mn-doped semiconductor nanocrystals have invariably exhibited photoluminescence over a narrow energy window of width ≤150 meV in the orange-red region and a surprisingly large spectral width (≥180 meV), contrary to its presumed atomic-like origin. Carrying out emission measurements on individual single nanocrystals and supported by ab initio calculations, we show that Mn PL emission, in fact, can (i) vary over a much wider range (∼370 meV) covering the deep green--deep red region and (ii) exhibit widths substantially lower (∼60-75 meV) than reported so far, opening newer application possibilities and requiring a fundamental shift in our perception of the emission from Mn-doped semiconductor nanocrystals.
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Affiliation(s)
- Abhijit Hazarika
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Bangalore 560012, India
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27
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28
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Fainblat R, Frohleiks J, Muckel F, Yu JH, Yang J, Hyeon T, Bacher G. Quantum confinement-controlled exchange coupling in manganese(II)-doped CdSe two-dimensional quantum well nanoribbons. NANO LETTERS 2012; 12:5311-5317. [PMID: 22947204 DOI: 10.1021/nl302639k] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
The impact of quantum confinement on the exchange interaction between charge carriers and magnetic dopants in semiconductor nanomaterials has been controversially discussed for more than a decade. We developed manganese-doped CdSe quantum well nanoribbons with a strong quantum confinement perpendicular to the c-axis, showing distinct heavy hole and light hole resonances up to 300 K. This allows a separate study of the s-d and the p-d exchange interactions all the way up to room temperature. Taking into account the optical selection rules and the statistical distribution of the nanoribbons orientation on the substrate, a remarkable change in particular of the s-d exchange constant with respect to bulk is indicated. Room-temperature studies revealed an unusually high effective g-factor up to ~13 encouraging the implementation of the DMS quantum well nanoribbons for (room temperature) spintronic applications.
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Affiliation(s)
- Rachel Fainblat
- Werkstoffe der Elektrotechnik and CeNIDE, Universität Duisburg-Essen, Bismarckstrasse 81, 47057 Duisburg, Germany.
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29
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Brovelli S, Galland C, Viswanatha R, Klimov VI. Tuning radiative recombination in Cu-doped nanocrystals via electrochemical control of surface trapping. NANO LETTERS 2012; 12:4372-9. [PMID: 22793380 DOI: 10.1021/nl302182u] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
The incorporation of copper dopants into II-VI colloidal nanocrystals (NCs) leads to the introduction of intragap electronic states and the development of a new emission feature due to an optical transition which couples the NC conduction band to the Cu-ion state. The mechanism underlying Cu-related emission and specifically the factors that control the branching between the intrinsic and impurity-related emission channels remain unclear. Here, we address this problem by conducting spectro-electrochemical measurements on Cu-doped core/shell ZnSe/CdSe NCs. These measurements indicate that the distribution of photoluminescence (PL) intensity between the intrinsic and the impurity bands as well as the overall PL efficiency can be controlled by varying the occupancy of surface defect sites. Specifically, by activating hole traps under negative electrochemical potential (the Fermi level is raised), we can enhance the Cu band at the expense of band-edge emission, which is consistent with the predominant Cu(2+) character of the dopant ions. Furthermore, we observe an overall PL "brightening" under negative potential and "dimming" under positive potential, which we attribute to changes in the occupancy of the electron trap sites (that is, the degree of their electronic passivation) that control nonradiative losses due to electron surface trapping.
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Affiliation(s)
- Sergio Brovelli
- Center for Advanced Solar Photophysics, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
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30
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Abolfath RM, Korkusinski M, Brabec T, Hawrylak P. Spin textures in strongly coupled electron spin and magnetic or nuclear spin systems in quantum dots. PHYSICAL REVIEW LETTERS 2012; 108:247203. [PMID: 23004315 DOI: 10.1103/physrevlett.108.247203] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2011] [Revised: 02/20/2012] [Indexed: 06/01/2023]
Abstract
Controlling electron spins strongly coupled to magnetic and nuclear spins in solid state systems is an important challenge in the field of spintronics and quantum computation. We show here that electron droplets with no net spin in semiconductor quantum dots strongly coupled with magnetic ion or nuclear spin systems break down at low temperature and form a nontrivial antiferromagnetic spatially ordered spin texture of magnetopolarons. The spatially ordered combined electron-magnetic ion spin texture, associated with spontaneous symmetry breaking in the parity of electronic charge and spin densities and magnetization of magnetic ions, emerges from an ab initio density functional approach to the electronic system coupled with mean-field approximation for the magnetic or nuclear spin system. The predicted phase diagram determines the critical temperature as a function of coupling strength and identifies possible phases of the strongly coupled spin system. The prediction may arrest fluctuations in the spin system and open the way to control, manipulate, and prepare magnetic and nuclear spin ensembles in semiconductor nanostructures.
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Affiliation(s)
- Ramin M Abolfath
- School of Natural Sciences and Mathematics, University of Texas at Dallas, Richardson, Texas 75080, USA
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31
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Freitas Neto ES, Dantas NO, Lourenço SA, Teodoro MD, Marques GE. Magneto-optical properties of Cd1−xMnxS nanoparticles: influences of magnetic doping, Mn2+ ions localization, and quantum confinement. Phys Chem Chem Phys 2012; 14:3248-55. [DOI: 10.1039/c2cp23492k] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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