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Li GL, Wu SY, Fan KM. Investigations on the defect structures for Mn 2+ in CdSe nanocrystals and bulk materials and the criterion of occupation for Mn 2+ in CdX (X = S, Se, Te) nanocrystals. MAGNETIC RESONANCE IN CHEMISTRY : MRC 2024; 62:610-618. [PMID: 38666325 DOI: 10.1002/mrc.5446] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2024] [Revised: 03/26/2024] [Accepted: 03/27/2024] [Indexed: 07/06/2024]
Abstract
The spin Hamiltonian parameters and defect structures are theoretically studied for the substitutional Mn2+ at the core of CdSe nanocrystals and in the bulk materials from the perturbation calculations of spin Hamiltonian parameters for trigonal tetrahedral 3d5 clusters. Both the crystal-field and charge transfer contributions are taken into account in the calculations from the cluster approach. The impurity-ligand bond angles are found to be about 1.84° larger and 0.10° smaller in the CdSe:Mn2+ nanocrystals and bulk materials, respectively, than those (≈109.37°) of the host Cd2+ sites. The quantitative criterion of occupation (at the core or surface) for Mn2+ in CdX (X = S, Se, Te) nanocrystals is presented for the first time based on the inequations of hyperfine structure constants (HSCs). This criterion is well supported by the experimental HSCs data of Mn2+ in CdX nanocrystals. The previous assignments of signals SI as Mn2+ at the core of CdS nanocrystals are renewed as Mn2+ at the surface based on the above criterion. The present studies would be helpful to achieve convenient determination of occupation for Mn2+ impurities in CdX semiconductor nanocrystals by means of spectral (e.g., HSCs) analysis.
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Affiliation(s)
- Guo-Liang Li
- College of Physics and Engineering Technology, Minzu Normal University of Xingyi, Xingyi, China
| | - Shao-Yi Wu
- Department of Applied Physics, School of Physics, University of Electronic Science and Technology of China, Chengdu, China
| | - Kai-Min Fan
- General Education Centre, Qinghai University of Technology, Xining, China
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2
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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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3
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Steenbock T, Rybakowski LLM, Benner D, Herrmann C, Bester G. Exchange Spin Coupling in Optically Excited States. J Chem Theory Comput 2022; 18:4708-4718. [PMID: 35797603 DOI: 10.1021/acs.jctc.2c00256] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
In optically excited states in molecules and materials, coupling between local electron spins plays an important role for their photoemission properties and is interesting for potential applications in quantum information processing. Recently, it was experimentally demonstrated that the photogenerated local spins in donor-acceptor metal complexes can interact with the spin of an attached radical, resulting in a spin-coupling-dependent mixing of excited doublet states, which controls the local spin density distributions on donor, acceptor, and radical subunits in optically excited states. In this work, we propose an energy-difference scheme to evaluate spin coupling in optically excited states, using unrestricted and spin-flip simplified time-dependent density functional theory. We apply it to three platinum complexes which have been studied experimentally to validate our methodology. We find that all computed coupling constants are in excellent agreement with the experimental data. In addition, we show that the spin coupling between donor and acceptor in the optically excited state can be fine-tuned by replacing platinum with palladium and zinc in the structure. Besides the two previously discussed excited doublet states (one bright and one dark), our calculations reveal a third, bright excited doublet state which was not considered previously. This third state possesses the inverse spin polarization on donor and acceptor with respect to the previously studied bright doublet state and is by an order of magnitude brighter, which might be interesting for optically controlling local spin polarizations with potential applications in spin-only information transfer and manipulation of connected qubits.
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Affiliation(s)
- Torben Steenbock
- Department of Chemistry, University of Hamburg, HARBOR, Building 610, Luruper Chaussee 149, Hamburg 22761, Germany
| | - Lawrence L M Rybakowski
- Department of Chemistry, University of Hamburg, HARBOR, Building 610, Luruper Chaussee 149, Hamburg 22761, Germany
| | - Dominik Benner
- Department of Chemistry, University of Hamburg, HARBOR, Building 610, Luruper Chaussee 149, Hamburg 22761, Germany
| | - Carmen Herrmann
- Department of Chemistry, University of Hamburg, HARBOR, Building 610, Luruper Chaussee 149, Hamburg 22761, Germany.,The Hamburg Centre for Ultrafast Imaging, Luruper Chaussee 149, Hamburg 22761, Germany
| | - Gabriel Bester
- Department of Chemistry, University of Hamburg, HARBOR, Building 610, Luruper Chaussee 149, Hamburg 22761, Germany.,Department of Physics, University of Hamburg, HARBOR, Building 610, Luruper Chaussee 149, Hamburg 22761, Germany.,The Hamburg Centre for Ultrafast Imaging, Luruper Chaussee 149, Hamburg 22761, Germany
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Rtimi S, Kiwi J, Nadtochenko V. Photo-induced environmental remediation, biomedical imaging, and microbial inactivation by Mn-doped semiconductors: critical issues. Curr Opin Chem Eng 2021. [DOI: 10.1016/j.coche.2021.100731] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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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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Lorenz S, Bieniek J, Erickson CS, Gamelin DR, Fainblat R, Bacher G. Orientation of Individual Anisotropic Nanocrystals Identified by Polarization Fingerprint. ACS NANO 2021; 15:13579-13590. [PMID: 34339182 DOI: 10.1021/acsnano.1c04451] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
The polarization of photoluminescence emitted from anisotropic nanocrystals directly reflects the symmetry of the eigenstates involved in the recombination process and can thus be considered as a characteristic feature of a nanocrystal. We performed polarization resolved magneto-photoluminescence spectroscopy on single colloidal Mn2+:CdSe/CdS core-shell quantum dots of wurtzite crystal symmetry. At zero magnetic field, a distinct linear polarization pattern is observed, while applying a magnetic field enforces circularly polarized emission with a characteristic saturation value below 100%. These polarization features are shown to act as a specific fingerprint of each individual nanocrystal. A model considering the orientation of the crystal c⃗ axis with respect to the optical axis and the magnetic field and taking into account the impact of magnetic doping is introduced and quantitatively explains our findings. We demonstrate that a careful analysis of the polarization state of single nanocrystal emission using the full set of Stokes parameters allows for identification of the complete three-dimensional orientation of the crystal anisotropy axis of an individual nanoobject in lab coordinates.
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Affiliation(s)
- Severin Lorenz
- Werkstoffe der Elektrotechnik and CENIDE, University of Duisburg-Essen, Bismarckstr. 81, Duisburg 47057 Germany
| | - Jan Bieniek
- Werkstoffe der Elektrotechnik and CENIDE, University of Duisburg-Essen, Bismarckstr. 81, Duisburg 47057 Germany
| | - Christian S Erickson
- Department of Chemistry, University of Washington, Seattle, Washington 98195-1700, United States
| | - Daniel R Gamelin
- Department of Chemistry, University of Washington, Seattle, Washington 98195-1700, United States
| | - Rachel Fainblat
- Werkstoffe der Elektrotechnik and CENIDE, University of Duisburg-Essen, Bismarckstr. 81, Duisburg 47057 Germany
| | - Gerd Bacher
- Werkstoffe der Elektrotechnik and CENIDE, University of Duisburg-Essen, Bismarckstr. 81, Duisburg 47057 Germany
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Zhang X, Tang B, Li Y, Liu C, Jiao P, Wei Y. Molecularly Imprinted Magnetic Fluorescent Nanocomposite-Based Sensor for Selective Detection of Lysozyme. NANOMATERIALS (BASEL, SWITZERLAND) 2021; 11:1575. [PMID: 34203859 PMCID: PMC8232576 DOI: 10.3390/nano11061575] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/23/2021] [Revised: 06/08/2021] [Accepted: 06/11/2021] [Indexed: 12/26/2022]
Abstract
A new strategy for the design and construction of molecularly imprinted magnetic fluorescent nanocomposite-based-sensor is proposed. This multifunctional nanocomposite exhibits the necessary optics, magnetism and biocompatibility for use in the selective fluorescence detection of lysozyme. The magnetic fluorescent nanocomposites are prepared by combining carboxyl- functionalized Fe3O4 magnetic nanoparticles with l-cysteine-modified zinc sulfide quantum dots (MNP/QDs). Surface molecular imprinting technology was employed to coat the lysozyme molecularly imprinted polymer (MIP) layer on the MNP/QDs to form a core-shell structure. The molecularly imprinted MNP/QDs (MNP/QD@MIPs) can rapidly separate the target protein and then use fluorescence sensing to detect the protein; this reduces the background interference, and the selectivity and sensitivity of the detection are improved. The molecularly imprinted MNP/QDs sensor presented good linearity over a lysozyme concentration range from 0.2 to 2.0 μM and a detection limit of 4.53 × 10-3 μM for lysozyme. The imprinting factor of the MNP/QD@MIPs was 4.12, and the selectivity coefficient ranged from 3.19 to 3.85. Furthermore, the MNP/QD@MIPs sensor was applied to detect of lysozyme in human urine and egg white samples with recoveries of 95.40-103.33%. Experimental results showed that the prepared MNP/QD@MIPs has potential for selective magnetic separation and fluorescence sensing of target proteins in biological samples.
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Affiliation(s)
- Xin Zhang
- School of Life Science and Agricultural Engineering, Nanyang Normal University, Nanyang 473061, China; (Y.L.); (C.L.); (P.J.); (Y.W.)
| | - Bo Tang
- Key Laboratory of Molecular Medicine and Biotherapy, School of Life Science, Beijing Institute of Technology, Beijing 100081, China;
| | - Yansong Li
- School of Life Science and Agricultural Engineering, Nanyang Normal University, Nanyang 473061, China; (Y.L.); (C.L.); (P.J.); (Y.W.)
| | - Chengbin Liu
- School of Life Science and Agricultural Engineering, Nanyang Normal University, Nanyang 473061, China; (Y.L.); (C.L.); (P.J.); (Y.W.)
| | - Pengfei Jiao
- School of Life Science and Agricultural Engineering, Nanyang Normal University, Nanyang 473061, China; (Y.L.); (C.L.); (P.J.); (Y.W.)
| | - Yuping Wei
- School of Life Science and Agricultural Engineering, Nanyang Normal University, Nanyang 473061, China; (Y.L.); (C.L.); (P.J.); (Y.W.)
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Halder O, Mallik G, Suffczyński J, Pacuski W, Varadwaj KSK, Satpati B, Rath S. Enhanced exciton binding energy, Zeeman splitting and spin polarization in hybrid layered nanosheets comprised of (Cd, Mn)Se and nitrogen-doped graphene oxide: implication for semiconductor devices. NANOTECHNOLOGY 2021; 32:325204. [PMID: 33946057 DOI: 10.1088/1361-6528/abfdee] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/26/2020] [Accepted: 05/04/2021] [Indexed: 06/12/2023]
Abstract
The exciton properties of (Cd,Mn)Se-NrGO (nitrogen doped reduced graphene oxide) hybrid layered nanosheets have been studied in a magnetic field up to 10 T and compared to those of (Cd,Mn)Se nanosheets. The temperature dependent photoluminescence reveals the hybridization of inter-band exciton and intra-center Mn transition with enhancement of the binding energy of exciton-Mn hybridized state (80 meV with respect to 60 meV in (Cd,Mn)Se nanosheets) and increase of exciton-phonon coupling strength to 90 meV (with respect to 55 meV in (Cd,Mn)Se nanosheets). The circularly polarized magneto-photoluminescence at 2 K provides evidence for magnetic field induced exciton spin polarization and the realization of excitonic giant Zeeman splitting withgeffas high as 165.4 ± 10.3, much larger than in the case of (Cd,Mn)Se nanosheets (63.9 ± 6.6), promising for implementation in spin active semiconductor devices.
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Affiliation(s)
- Oindrila Halder
- School of Basic Sciences, Indian Institute of Technology Bhubaneswar, Jatni, Khordha 752050, India
| | - Gyanadeep Mallik
- School of Basic Sciences, Indian Institute of Technology Bhubaneswar, Jatni, Khordha 752050, India
| | - Jan Suffczyński
- Institute of Experimental Physics, Faculty of Physics, University of Warsaw, Pasteura 5, Warsaw 02 093, Poland
| | - Wojciech Pacuski
- Institute of Experimental Physics, Faculty of Physics, University of Warsaw, Pasteura 5, Warsaw 02 093, Poland
| | | | - Biswarup Satpati
- Saha Institute of Nuclear Physics, 1/AF Bidhannagar, Kolkata 700064, India
| | - Satchidananda Rath
- School of Basic Sciences, Indian Institute of Technology Bhubaneswar, Jatni, Khordha 752050, India
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9
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Shornikova EV, Yakovlev DR, Tolmachev DO, Ivanov VY, Kalitukha IV, Sapega VF, Kudlacik D, Kusrayev YG, Golovatenko AA, Shendre S, Delikanli S, Demir HV, Bayer M. Magneto-Optics of Excitons Interacting with Magnetic Ions in CdSe/CdMnS Colloidal Nanoplatelets. ACS NANO 2020; 14:9032-9041. [PMID: 32585089 DOI: 10.1021/acsnano.0c04048] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Excitons in diluted magnetic semiconductors represent excellent probes for studying the magnetic properties of these materials. Various magneto-optical effects, which depend sensitively on the exchange interaction of the excitons with the localized spins of the magnetic ions can be used for probing. Here, we study core/shell CdSe/(Cd,Mn)S colloidal nanoplatelets hosting diluted magnetic semiconductor layers. The inclusion of the magnetic Mn2+ ions is evidenced by three magneto-optical techniques using high magnetic fields up to 15 T: polarized photoluminescence, optically detected magnetic resonance, and spin-flip Raman scattering. We show that the holes in the excitons play the dominant role in exchange interaction with magnetic ions. We suggest and test an approach for evaluation of the Mn2+ concentration based on the spin-lattice relaxation dynamics of the Mn2+ spin system.
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Affiliation(s)
- Elena V Shornikova
- Experimentelle Physik 2, Technische Universität Dortmund, 44227 Dortmund, Germany
| | - Dmitri R Yakovlev
- Experimentelle Physik 2, Technische Universität Dortmund, 44227 Dortmund, Germany
- Ioffe Institute, Russian Academy of Sciences, 194021 St. Petersburg, Russia
| | - Danil O Tolmachev
- Experimentelle Physik 2, Technische Universität Dortmund, 44227 Dortmund, Germany
- Ioffe Institute, Russian Academy of Sciences, 194021 St. Petersburg, Russia
| | - Vitalii Yu Ivanov
- Institute of Physics, Polish Academy of Sciences, PL-02-668 Warsaw, Poland
| | - Ina V Kalitukha
- Ioffe Institute, Russian Academy of Sciences, 194021 St. Petersburg, Russia
| | - Victor F Sapega
- Ioffe Institute, Russian Academy of Sciences, 194021 St. Petersburg, Russia
| | - Dennis Kudlacik
- Experimentelle Physik 2, Technische Universität Dortmund, 44227 Dortmund, Germany
| | - Yuri G Kusrayev
- Ioffe Institute, Russian Academy of Sciences, 194021 St. Petersburg, Russia
| | | | - Sushant Shendre
- LUMINOUS! Center of Excellence for Semiconductor Lighting and Displays, School of Electrical and Electronic Engineering, School of Physical and Materials Sciences, Nanyang Technological University, 639798 Singapore
| | - Savas Delikanli
- LUMINOUS! Center of Excellence for Semiconductor Lighting and Displays, School of Electrical and Electronic Engineering, School of Physical and Materials Sciences, Nanyang Technological University, 639798 Singapore
- Department of Electrical and Electronics Engineering, Department of Physics, UNAM - Institute of Materials Science and Nanotechnology, Bilkent University, 06800 Ankara, Turkey
| | - Hilmi Volkan Demir
- LUMINOUS! Center of Excellence for Semiconductor Lighting and Displays, School of Electrical and Electronic Engineering, School of Physical and Materials Sciences, Nanyang Technological University, 639798 Singapore
- Department of Electrical and Electronics Engineering, Department of Physics, UNAM - Institute of Materials Science and Nanotechnology, Bilkent University, 06800 Ankara, Turkey
| | - Manfred Bayer
- Experimentelle Physik 2, Technische Universität Dortmund, 44227 Dortmund, Germany
- Ioffe Institute, Russian Academy of Sciences, 194021 St. Petersburg, Russia
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