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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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Pimachev A, Rimal G, Nielsen RD, Tang J, Dahnovsky Y. Room temperature d 0 ferromagnetism in PbS films: nonuniform distribution of Pb vacancies. Phys Chem Chem Phys 2018; 20:29804-29810. [PMID: 30465566 DOI: 10.1039/c8cp04882g] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Because of the importance of ferromagnetism at room temperature, we search for new materials that can exhibit a non-vanishing magnetic moment at room temperature and at the same time can be used in spintronics. The experimental results indicate that d0 ferromagnetism without any magnetic impurities takes place in PbS films made of close-packed lead sulfide nanoparticles of 30 nm. To explain the existence of the d0 ferromagnetism, we propose a model where various PbS bulk and surface configurations of Pb-vacancies are analyzed. The bulk configurations have a zero magnetic moment while the two surface configurations with Pb vacancies with the same non-vanishing magnetic moments and lowest ground state energies contribute to the total magnetization. Based on the experimental value of the saturation magnetization, 0.2 emu g-1, we have found that the calculated Pb vacancy concentration should be about 3.5%, which is close to typical experimental values. Besides being very important for applications, there is one feature of PbS d0 ferromagnetism that makes this material special for fundamental research: PbS ferromagnetism can exhibit topologically driven spatial magnetic moment distributions (e.g., magnetic skyrmions) due to large spin-orbit coupling.
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Affiliation(s)
- Artem Pimachev
- Department of Physics & Astronomy/3905, 1000 E. University Avenue, University of Wyoming, Laramie, WY 82071, USA.
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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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Pimachev A, Poudyal U, Proshchenko V, Wang W, Dahnovsky Y. Large enhancement in photocurrent by Mn doping in CdSe/ZTO quantum dot sensitized solar cells. Phys Chem Chem Phys 2016; 18:26771-26776. [DOI: 10.1039/c6cp04263e] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
In the presence of Mn impurities in relatively small concentrations (2.3%) the photoelectric current of CdSe QDSCCs increases by up to 190%. We propose an electron tunneling mechanism from the quantum dot LUMO state to the Zn2SnO4 semiconductor photoanode.
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Affiliation(s)
- Artem Pimachev
- Department of Physics and Astronomy/3905
- University of Wyoming
- Laramie
- USA
| | - Uma Poudyal
- Department of Physics and Astronomy/3905
- University of Wyoming
- Laramie
- USA
| | | | - Wenyong Wang
- Department of Physics and Astronomy/3905
- University of Wyoming
- Laramie
- USA
| | - Yuri Dahnovsky
- Department of Physics and Astronomy/3905
- University of Wyoming
- Laramie
- USA
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