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Gas K, Kret S, Zaleszczyk W, Kamińska E, Sawicki M, Wojtowicz T, Szuszkiewicz W. Oxidation of MBE-Grown ZnTe and ZnTe/Zn Nanowires and Their Structural Properties. Materials (Basel) 2021; 14:ma14185252. [PMID: 34576476 PMCID: PMC8469095 DOI: 10.3390/ma14185252] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/04/2021] [Revised: 09/01/2021] [Accepted: 09/07/2021] [Indexed: 12/23/2022]
Abstract
Results of comparative structural characterization of bare and Zn-covered ZnTe nanowires (NWs) before and after thermal oxidation at 300 °C are presented. Scanning electron microscopy, energy-dispersive X-ray spectroscopy, high-resolution transmission electron microscopy, and Raman scattering not only unambiguously confirm the conversion of the outer layer of the NWs into ZnO, but also demonstrate the influence of the oxidation process on the structure of the inner part of the NWs. Our study shows that the morphology of the resulting ZnO can be improved by the deposition of thin Zn shells on the bare ZnTe NWs prior to the oxidation. The oxidation of bare ZnTe NWs results in the formation of separated ZnO nanocrystals which decorate crystalline Te cores of the NWs. In the case of Zn-covered NWs, uniform ZnO shells are formed, however they are of a fine-crystalline structure or partially amorphous. Our study provides an important insight into the details of the oxidation processes of ZnTe nanostructures, which could be of importance for the preparation and performance of ZnTe based nano-devices operating under normal atmospheric conditions and at elevated temperatures.
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Affiliation(s)
- Katarzyna Gas
- Institute of Physics, Polish Academy of Sciences, Aleja Lotnikow 32/46, PL-02668 Warsaw, Poland; (S.K.); (W.Z.); (M.S.); (W.S.)
- Correspondence:
| | - Slawomir Kret
- Institute of Physics, Polish Academy of Sciences, Aleja Lotnikow 32/46, PL-02668 Warsaw, Poland; (S.K.); (W.Z.); (M.S.); (W.S.)
| | - Wojciech Zaleszczyk
- Institute of Physics, Polish Academy of Sciences, Aleja Lotnikow 32/46, PL-02668 Warsaw, Poland; (S.K.); (W.Z.); (M.S.); (W.S.)
- International Research Centre MagTop, Institute of Physics, Polish Academy of Sciences, Aleja Lotnikow 32/46, PL-02668 Warsaw, Poland;
| | - Eliana Kamińska
- Institute of High Pressure Physics Unipress, Al. Prymasa Tysiaclecia 98, PL-01142 Warsaw, Poland;
| | - Maciej Sawicki
- Institute of Physics, Polish Academy of Sciences, Aleja Lotnikow 32/46, PL-02668 Warsaw, Poland; (S.K.); (W.Z.); (M.S.); (W.S.)
| | - Tomasz Wojtowicz
- International Research Centre MagTop, Institute of Physics, Polish Academy of Sciences, Aleja Lotnikow 32/46, PL-02668 Warsaw, Poland;
| | - Wojciech Szuszkiewicz
- Institute of Physics, Polish Academy of Sciences, Aleja Lotnikow 32/46, PL-02668 Warsaw, Poland; (S.K.); (W.Z.); (M.S.); (W.S.)
- Institute of Physics, College of Natural Sciences, University of Rzeszow, S. Pigonia 1, PL-35310 Rzeszow, Poland
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Kamińska I, Wosztyl A, Kowalik P, Sikora B, Wojciechowski T, Sobczak K, Minikayev R, Zajdel K, Chojnacki M, Zaleszczyk W, Łysiak K, Paszkowicz W, Szczytko J, Frontczak-Baniewicz M, Stryczniewicz W, Fronc K. Synthesis and characterization of Gd 2O 3: Er 3+, Yb 3+doped with Mg 2+, Li +ions-effect on the photoluminescence and biological applications. Nanotechnology 2021; 32:245705. [PMID: 33690193 DOI: 10.1088/1361-6528/abed02] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Accepted: 03/09/2021] [Indexed: 06/12/2023]
Abstract
Gd2O3:1% Er3+, 18% Yb3+,x% Mg2+(x = 0; 2.5; 4; 5; 6; 8;10; 20; 25; 50) and Gd2O3:1% Er3+, 18% Yb3+, 2,5% Mg2+,y% Li+(y = 0.5-2.5) nanoparticles were synthesized by homogenous precipitation method and calcined at 900 °C for 3 h in air atmosphere. Powder x-ray diffraction, scanning electron microscopy, cathodoluminescence, transmission electron microscopy, energy dispersive x-ray spectroscopy and photoluminescence techniques were employed to characterize the obtained nanoparticles. We observed a 8-fold increase in red luminescence for samples suspended in DMSO solution for 2.5% of Mg2+doping. The x-ray analysis shows that for the concentration of 2.5% Mg, the size of the crystallites in the NPs is the largest, which is mainly responsible for the increase in the intensity of the upconversion luminescence. But the addition of Li+ions did not improve the luminescence of the upconversion due to decreasing of crystallites size of the NPs. Synthesized nanomaterials with very effective upconverting luminescence, can act as luminescent markers inin vivoimaging. The cytotoxicity of the nanoparticles was evaluated on the 4T1 cell line for the first time.
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Affiliation(s)
- Izabela Kamińska
- Institute of Physics Polish Academy of Sciences, al. Lotników 32/46, Warsaw 02-668, Poland
| | - Aleksandra Wosztyl
- Institute of Physics Polish Academy of Sciences, al. Lotników 32/46, Warsaw 02-668, Poland
- Institute of Experimental Physics, Faculty of Physics, University of Warsaw, 02-093, Poland
| | - Przemysław Kowalik
- Institute of Physics Polish Academy of Sciences, al. Lotników 32/46, Warsaw 02-668, Poland
| | - Bożena Sikora
- Institute of Physics Polish Academy of Sciences, al. Lotników 32/46, Warsaw 02-668, Poland
| | - Tomasz Wojciechowski
- Institute of Physics Polish Academy of Sciences, al. Lotników 32/46, Warsaw 02-668, Poland
- International Research Centre MagTop, al. Lotników 32/46, Warsaw 02-668, Poland
| | - Kamil Sobczak
- Faculty of Chemistry, Biological and Chemical Research Centre, University of Warsaw, Żwirki i Wigury 101, Warsaw 02-089, Poland
| | - Roman Minikayev
- Institute of Physics Polish Academy of Sciences, al. Lotników 32/46, Warsaw 02-668, Poland
| | - Karolina Zajdel
- Mossakowski Medical Research Centre, Polish Academy of Sciences, Pawińskiego 5, Warsaw 02-106, Poland
| | - Michał Chojnacki
- Institute of Physics Polish Academy of Sciences, al. Lotników 32/46, Warsaw 02-668, Poland
| | - Wojciech Zaleszczyk
- Institute of Physics Polish Academy of Sciences, al. Lotników 32/46, Warsaw 02-668, Poland
- International Research Centre MagTop, al. Lotników 32/46, Warsaw 02-668, Poland
| | - Katarzyna Łysiak
- Faculty of Physics, University of Warsaw, Ludwika Pasteura 5, 02-093, Poland
| | - Wojciech Paszkowicz
- Institute of Physics Polish Academy of Sciences, al. Lotników 32/46, Warsaw 02-668, Poland
| | - Jacek Szczytko
- Institute of Experimental Physics, Faculty of Physics, University of Warsaw, 02-093, Poland
| | | | - Wit Stryczniewicz
- Łukasiewicz Research Network-Institute of Aviation, al. Krakowska 110/114, Warsaw 02-256, Poland
| | - Krzysztof Fronc
- Institute of Physics Polish Academy of Sciences, al. Lotników 32/46, Warsaw 02-668, Poland
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3
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Kamińska I, Elbaum D, Sikora B, Kowalik P, Mikulski J, Felcyn Z, Samol P, Wojciechowski T, Minikayev R, Paszkowicz W, Zaleszczyk W, Szewczyk M, Konopka A, Gruzeł G, Pawlyta M, Donten M, Ciszak K, Zajdel K, Frontczak-Baniewicz M, Stępień P, Łapiński M, Wilczyński G, Fronc K. Single-step synthesis of Er 3+ and Yb 3+ ions doped molybdate/Gd 2O 3 core-shell nanoparticles for biomedical imaging. Nanotechnology 2018; 29:025702. [PMID: 29130898 DOI: 10.1088/1361-6528/aa9974] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Nanostructures as color-tunable luminescent markers have become major, promising tools for bioimaging and biosensing. In this paper separated molybdate/Gd2O3 doped rare earth ions (erbium, Er3+ and ytterbium, Yb3+) core-shell nanoparticles (NPs), were fabricated by a one-step homogeneous precipitation process. Emission properties were studied by cathodo- and photoluminescence. Scanning electron and transmission electron microscopes were used to visualize and determine the size and shape of the NPs. Spherical NPs were obtained. Their core-shell structures were confirmed by x-ray diffraction and energy-dispersive x-ray spectroscopy measurements. We postulated that the molybdate rich core is formed due to high segregation coefficient of the Mo ion during the precipitation. The calcination process resulted in crystallization of δ/ξ (core/shell) NP doped Er and Yb ions, where δ-gadolinium molybdates and ξ-molybdates or gadolinium oxide. We confirmed two different upconversion mechanisms. In the presence of molybdenum ions, in the core of the NPs, Yb3+-[Formula: see text] (∣2F7/2, 3T2〉) dimers were formed. As a result of a two 980 nm photon absorption by the dimer, we observed enhanced green luminescence in the upconversion process. However, for the shell formed by the Gd2O3:Er, Yb NPs (without the Mo ions), the typical energy transfer upconversion takes place, which results in red luminescence. We demonstrated that the NPs were transported into cytosol of the HeLa and astrocytes cells by endocytosis. The core-shell NPs are sensitive sensors for the environment prevailing inside (shorter luminescence decay) and outside (longer luminescence decay) of the tested cells. The toxicity of the NPs was examined using MTT assay.
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Affiliation(s)
- Izabela Kamińska
- Institute of Physics Polish Academy of Sciences, al Lotników 32/46, Warsaw 02-668, Poland
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4
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Sikora B, Kowalik P, Mikulski J, Fronc K, Kamińska I, Szewczyk M, Konopka A, Zajdel K, Minikayev R, Sobczak K, Zaleszczyk W, Borodziuk A, Rybusiński J, Szczytko J, Sienkiewicz A, Wojciechowski T, Stępień P, Frontczak-Baniewicz M, Łapiński M, Wilczyński G, Paszkowicz W, Twardowski A, Elbaum D. Mammalian cell defence mechanisms against the cytotoxicity of NaYF 4:(Er,Yb,Gd) nanoparticles. Nanoscale 2017; 9:14259-14271. [PMID: 28914943 DOI: 10.1039/c7nr03705h] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Water-soluble upconversion nanoparticles (UCNPs), based on polyvinylpyrrolidone (PVP)-coated NaYF4:Er3+,Yb3+,Gd3+, with various concentrations of Gd3+ ions and relatively high upconversion efficiencies, were synthesized. The internalization and cytotoxicity of the thus obtained UCNPs were evaluated in three cell lines (HeLa, HEK293 and astrocytes). No cytotoxicity was observed even at concentrations of UCNPs up to 50 μg ml-1. The fate of the UCNPs within the cells was studied by examining their upconversion emission spectra with confocal microscopy and confirming these observations with transmission electron microscopy. It was found that the cellular uptake of the UCNPs occurred primarily by clathrin-mediated endocytosis, whereas they were secreted from the cells via lysosomal exocytosis. The results of this study, focused on the mechanisms of the cellular uptake, localization and secretion of UCNPs, demonstrate, for the first time, the co-localization of UCNPs within discrete cell organelles.
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Affiliation(s)
- B Sikora
- Institute of Physics, Polish Academy of Sciences, Al. Lotnikow 42/46, PL-02668, Warsaw, Poland.
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5
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Wojnar P, Płachta J, Kret S, Kaleta A, Zaleszczyk W, Szymura M, Wiater M, Baczewski LT, Pietruczik A, Karczewski G, Wojtowicz T, Kossut J. Growth and optical investigations of high quality individual CdTe/(Cd,Mg)Te core/shell nanowires. Nanotechnology 2017; 28:045207. [PMID: 28000610 DOI: 10.1088/1361-6528/28/4/045207] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
CdTe nanowires with the average diameter of only 40 nm coated with (Cd,Mg)Te shells are grown using Au-catalyzed vapor-liquid-solid growth mechanism in a system for molecular beam epitaxy. High optical quality of individual nanowires is revealed by means of low temperature cathodoluminescence and micro-luminescence. It is found that, the optical emission spectrum consists mostly of the near band edge emission without any significant contribution of defect related luminescence. Moreover, the importance of surface passivation with (Cd,Mg)Te coating shells is demonstrated.
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Affiliation(s)
- P Wojnar
- Institute of Physics, Polish Academy of Sciences, Aleja Lotnikow 32/46, PL-02668 Warsaw, Poland
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6
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Wojnar P, Płachta J, Zaleszczyk W, Kret S, Sanchez AM, Rudniewski R, Raczkowska K, Szymura M, Karczewski G, Baczewski LT, Pietruczik A, Wojtowicz T, Kossut J. Coexistence of optically active radial and axial CdTe insertions in single ZnTe nanowire. Nanoscale 2016; 8:5720-5727. [PMID: 26903109 DOI: 10.1039/c5nr08806b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
We report on the growth, cathodoluminescence and micro-photoluminescence of individual radial and axial CdTe insertions in ZnTe nanowires. In particular, the cathodoluminescence technique is used to determine the position of each emitting object inside the nanowire. It is demonstrated that depending on the CdTe deposition temperature, one can obtain an emission either from axial CdTe insertions only, or from both, radial and axial heterostructures, simultaneously. At 350 °C CdTe grows only axially, whereas at 310 °C and 290 °C, there is also significant deposition on the nanowire sidewalls resulting in radial core/shell heterostructures. The presence of Cd atoms on the sidewalls is confirmed by energy dispersive X-ray spectroscopy. Micro-photoluminescence study reveals a strong linear polarization of the emission from both types of heterostructures in the direction along the nanowire axis.
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Affiliation(s)
- P Wojnar
- Institute of Physics, Polish Academy of Sciences, Al. Lotników 32/46, Warsaw, Poland
| | - J Płachta
- Institute of Physics, Polish Academy of Sciences, Al. Lotników 32/46, Warsaw, Poland
| | - W Zaleszczyk
- Institute of Physics, Polish Academy of Sciences, Al. Lotników 32/46, Warsaw, Poland
| | - S Kret
- Institute of Physics, Polish Academy of Sciences, Al. Lotników 32/46, Warsaw, Poland
| | - Ana M Sanchez
- Department of Physics, University of Warwick, Coventry CV4 7AL, UK.
| | - R Rudniewski
- Institute of Physics, Polish Academy of Sciences, Al. Lotników 32/46, Warsaw, Poland
| | - K Raczkowska
- Institute of Physics, Polish Academy of Sciences, Al. Lotników 32/46, Warsaw, Poland
| | - M Szymura
- Institute of Physics, Polish Academy of Sciences, Al. Lotników 32/46, Warsaw, Poland
| | - G Karczewski
- Institute of Physics, Polish Academy of Sciences, Al. Lotników 32/46, Warsaw, Poland
| | - L T Baczewski
- Institute of Physics, Polish Academy of Sciences, Al. Lotników 32/46, Warsaw, Poland
| | - A Pietruczik
- Institute of Physics, Polish Academy of Sciences, Al. Lotników 32/46, Warsaw, Poland
| | - T Wojtowicz
- Institute of Physics, Polish Academy of Sciences, Al. Lotników 32/46, Warsaw, Poland
| | - J Kossut
- Institute of Physics, Polish Academy of Sciences, Al. Lotników 32/46, Warsaw, Poland
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7
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Szymura M, Wojnar P, Kłopotowski Ł, Suffczyński J, Goryca M, Smoleński T, Kossacki P, Zaleszczyk W, Wojciechowski T, Karczewski G, Wojtowicz T, Kossut J. Spin splitting anisotropy in single diluted magnetic nanowire heterostructures. Nano Lett 2015; 15:1972-1978. [PMID: 25710186 DOI: 10.1021/nl504853m] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
We study the impact of the nanowire shape anisotropy on the spin splitting of excitonic photoluminescence. The experiments are performed on individual ZnMnTe/ZnMgTe core/shell nanowires as well as on ZnTe/ZnMgTe core/shell nanowires containing optically active magnetic CdMnTe insertions. When the magnetic field is oriented parallel to the nanowire axis, the spin splitting is several times larger than for the perpendicular field. We interpret this pronounced anisotropy as an effect of mixing of valence band states arising from the strain present in the core/shell geometry. This interpretation is further supported by theoretical calculations which allow to reproduce experimental results.
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Affiliation(s)
- Małgorzata Szymura
- Institute of Physics, Polish Academy of Sciences , Al Lotników 32/46, PL-02-668 Warsaw, Poland
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8
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Kamińska I, Fronc K, Sikora B, Mouawad M, Siemiarczuk A, Szewczyk M, Sobczak K, Wojciechowski T, Zaleszczyk W, Minikayev R, Paszkowicz W, Stępień P, Dziawa P, Ciszak K, Piątkowski D, Maćkowski S, Kaliszewski M, Włodarski M, Młyńczak J, Kopczyński K, Łapiński M, Elbaum D. Upconverting/magnetic: Gd2O3:(Er3+,Yb3+,Zn2+) nanoparticles for biological applications: effect of Zn2+ doping. RSC Adv 2015. [DOI: 10.1039/c5ra11888c] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Upconverting/paramagnetic Gd2O3:1% Er3+, 18% Yb3+ with Zn2+ nanoparticles (NPs) permits one to perform optical imaging.
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9
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Wojnar P, Szymura M, Zaleszczyk W, Kłopotowski L, Janik E, Wiater M, Baczewski LT, Kret S, Karczewski G, Kossut J, Wojtowicz T. Activation of an intense near band edge emission from ZnTe/ZnMgTe core/shell nanowires grown on silicon. Nanotechnology 2013; 24:365201. [PMID: 23960005 DOI: 10.1088/0957-4484/24/36/365201] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
The absence of luminescence in the near band edge energy region of Te-anion based semiconductor nanowires grown by gold catalyst assisted molecular beam epitaxy has strongly limited their applications in the field of photonics. In this paper, an enhancement of the near band edge emission intensity from ZnTe/ZnMgTe core/shell nanowires grown on Si substrates is reported. A special role of the use of Si substrates instead of GaAs substrates is emphasized, which results in an increase of the near band edge emission intensity by at least one order of magnitude accompanied by a simultaneous reduction of the defect related luminescence. A possible explanation of this effect relies on the presence of Ga-related deep level defects in structures grown on GaAs substrates, which are absent when Si substrates are used. Monochromatic mapping of the cathodoluminescence clearly confirms that the observed emission originates, indeed, from the ZnTe/ZnMgTe core/shell nanowires, whereas individual objects are studied by means of microphotoluminescence.
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Affiliation(s)
- P Wojnar
- Institute of Physics Polish Academy of Sciences, Aleja Lotników 32/46, 02-660 Warszawa, Poland.
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10
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Gas K, Sadowski J, Kasama T, Siusys A, Zaleszczyk W, Wojciechowski T, Morhange JF, Altintaş A, Xu HQ, Szuszkiewicz W. Structural and optical properties of self-catalytic GaAs:Mn nanowires grown by molecular beam epitaxy on silicon substrates. Nanoscale 2013; 5:7410-7418. [PMID: 23832244 DOI: 10.1039/c3nr01145c] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Mn-doped GaAs nanowires were grown in the self-catalytic growth mode on the oxidized Si(100) surface by molecular beam epitaxy and characterized by scanning and transmission electron microscopy, Raman scattering, photoluminescence, cathodoluminescence, and electron transport measurements. The transmission electron microscopy studies evidenced the substantial accumulation of Mn inside the catalyzing Ga droplets on the top of the nanowires. Optical and transport measurements revealed that the limit of the Mn content for self-catalysed growth of GaAs nanowires corresponds to the doping level, i.e., it is much lower than the Mn/Ga flux ratio (about 3%) used during the MBE growth. The resistivity measurements of individual nanowires confirmed that they are conductive, in accordance with the photoluminescence measurements which showed the presence of Mn(2+) acceptors located at Ga sites of the GaAs host lattice of the nanowires. An anomalous temperature dependence of the photoluminescence related to excitons was demonstrated for Mn-doped GaAs nanowires.
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Affiliation(s)
- Katarzyna Gas
- Institute of Physics, Polish Academy of Sciences, al. Lotników 32/46, PL-02-668 Warszawa, Poland.
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11
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Janik E, Wachnicka A, Guziewicz E, Godlewski M, Kret S, Zaleszczyk W, Dynowska E, Presz A, Karczewski G, Wojtowicz T. ZnTe-ZnO core-shell radial heterostructures grown by the combination of molecular beam epitaxy and atomic layer deposition. Nanotechnology 2010; 21:015302. [PMID: 19946158 DOI: 10.1088/0957-4484/21/1/015302] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
ZnTe-ZnO core-shell radial heterostructures were grown using a new method of combining molecular beam epitaxy (MBE) and atomic layer deposition (ALD). Zinc telluride nanowires (core) were grown on a GaAs substrate using gold catalyzed vapor-liquid-solid mechanism. An atomic layer deposition technique using diethyl zinc and deionized water as precursors was applied for zinc oxide shell formation. The core-shell ZnTe-ZnO heterostructures thus obtained were characterized by scanning electron microscopy, transmission electron microscopy, x-ray diffraction and photoluminescence measurements.
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Affiliation(s)
- E Janik
- Institute of Physics Polish Academy of Sciences, aleja Lotników 32/46, 02-660 Warszawa, Poland.
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12
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Ganichev SD, Tarasenko SA, Bel'kov VV, Olbrich P, Eder W, Yakovlev DR, Kolkovsky V, Zaleszczyk W, Karczewski G, Wojtowicz T, Weiss D. Spin currents in diluted magnetic semiconductors. Phys Rev Lett 2009; 102:156602. [PMID: 19518662 DOI: 10.1103/physrevlett.102.156602] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2008] [Indexed: 05/27/2023]
Abstract
We study zero-bias spin separation in (Cd,Mn)Te/(Cd,Mg)Te diluted magnetic semiconductor structures. The spin current generated by electron gas heating under terahertz radiation is converted into a net electric current by applying an external magnetic field. The experiments show that the spin polarization of the magnetic ion system enhances drastically the conversion process due to giant Zeeman splitting of the conduction band and spin-dependent electron scattering on localized Mn(2+) ions.
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Affiliation(s)
- S D Ganichev
- Terahertz Center, University of Regensburg, 93040 Regensburg, Germany
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13
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Zaleszczyk W, Janik E, Presz A, Dłuzewski P, Kret S, Szuszkiewicz W, Morhange JF, Dynowska E, Kirmse H, Neumann W, Petroutchik A, Baczewski LT, Karczewski G, Wojtowicz T. Zn(1-x)MnxTe diluted magnetic semiconductor nanowires grown by molecular beam epitaxy. Nano Lett 2008; 8:4061-4065. [PMID: 18842031 DOI: 10.1021/nl802449g] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
It is shown that the growth of II-VI diluted magnetic semiconductor nanowires is possible by the catalytically enhanced molecular beam epitaxy (MBE). Zn(1-x)MnxTe NWs with manganese content up to x=0.60 were produced by this method. X-ray diffraction, Raman spectroscopy, and temperature dependent photoluminescence measurements confirm the incorporation of Mn(2+) ions in the cation substitutional sites of the ZnTe matrix of the NWs.
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Affiliation(s)
- Wojciech Zaleszczyk
- Institute of Physics, Polish Academy of Sciences, Al. Lotników 32/46, 02-668 Warsaw, Poland.
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14
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Janik E, Dynowska E, Dłużewski P, Kret S, Presz A, Zaleszczyk W, Szuszkiewicz W, Morhange JF, Petroutchik A, Maćkowski S, Wojtowicz T. Zn(1-x)Mg(x)Te nanowires grown by solid source molecular beam epitaxy. Nanotechnology 2008; 19:365606. [PMID: 21828877 DOI: 10.1088/0957-4484/19/36/365606] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
This paper reports on the epitaxial growth of single-crystalline ternary Zn(1-x)Mg(x)Te nanowires covering a broad compositional range of molar fraction 0≤x≤0.75. The nanowires were grown on (100), (110), and (111) GaAs substrates using a vapor-liquid-solid mechanism. Solid source molecular beam epitaxy and an Au-based nanocatalyst were used for these purposes. The composition of nanowires can be adjusted by changing the ratio of Mg to Zn molecular beam fluxes. Electron microscopy images show that the nanowires are smooth and slightly tapered. The diameters of the obtained nanowires are from 30 to 70 nm and their length is around 1 µm. X-ray diffraction analysis and transmission electron microscopy reveal that the nanowires have a zinc-blende structure throughout the whole range of obtained compositions, and have a [Formula: see text] growth axis. The Raman measurements reveal both the expected splitting and shift of phonon lines with increasing Mg content, thus proving the substitutional incorporation of Mg into metallic sites of the ZnTe lattice.
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Affiliation(s)
- E Janik
- Institute of Physics, Polish Academy of Sciences, aleja Lotników 32/46, 02-660 Warszawa, Poland
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Neumann W, Kirmse H, Kret S, Dluzewski P, Janik E, Presz A, Karczewski G, Wojtowicz T, Zaleszczyk W. Analysis of atomic structure and structural imperfections of ZnTe and (Zn,Mn)Te nanowires. Acta Crystallogr A 2008. [DOI: 10.1107/s010876730808077x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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