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Gupta R, Pradhan J, Haldar A, Murapaka C, Chandra Mondal P. Chemical Approach Towards Broadband Spintronics on Nanoscale Pyrene Films. Angew Chem Int Ed Engl 2023; 62:e202307458. [PMID: 37363873 DOI: 10.1002/anie.202307458] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2023] [Revised: 06/26/2023] [Accepted: 06/26/2023] [Indexed: 06/28/2023]
Abstract
The injection of pure spin current into the non-magnetic layer plays a crucial role in transmitting, processing, and storing data information in the realm of spintronics. To understand broadband molecular spintronics, pyrene oligomer film (≈20 nm thickness) was prepared using an electrochemical method forming indium tin oxide (ITO) electrode/pyrene covalent interfaces. Permalloy (Ni80 Fe20 ) films with different nanoscale thicknesses were used as top contact over ITO/pyrene layers to estimate the spin pumping efficiency across the interfaces using broadband ferromagnetic resonance spectra. The spintronic devices are composed of permalloy/pyrene/ITO orthogonal configuration, showing remarkable spin pumping from permalloy to pyrene film. The large spin pumping is evident from the linewidth broadening of 5.4 mT at 9 GHz, which is direct proof of spin angular momentum transfer across the interface. A striking observation is made with the high spin-mixing conductance of ≈1.02×1018 m-2 , a value comparable to the conventional heavy metals. Large spin angular moment transfer was observed at the permalloy-pyrene interfaces, especially at the lower thickness of permalloy, indicating a strong spinterface effect. Pure spin current injection from ferromagnetic into electrochemically grown pyrene films ensures efficient broadband spin transport, which opens a new area in molecular broadband spintronics.
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Affiliation(s)
- Ritu Gupta
- Department of Chemistry, Indian Institute of Technology Kanpur, Uttar Pradesh, 208016, India
| | - Jhantu Pradhan
- Department of Physics, Indian Institute of Technology Hyderabad, Kandi-502285, Telangana, India
- Department of Materials Science and Metallurgical Engineering, Indian Institute of Technology Hyderabad, Kandi-502285, Telangana, India
| | - Arabinda Haldar
- Department of Physics, Indian Institute of Technology Hyderabad, Kandi-502285, Telangana, India
| | - Chandrasekhar Murapaka
- Department of Materials Science and Metallurgical Engineering, Indian Institute of Technology Hyderabad, Kandi-502285, Telangana, India
| | - Prakash Chandra Mondal
- Department of Chemistry, Indian Institute of Technology Kanpur, Uttar Pradesh, 208016, India
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Nicolaides C, Bazzi F, Vouros E, Flesariu DF, Chrysochos N, Koutentis PA, Constantinides CP, Trypiniotis T. Metal-Free Organic Radical Spin Source. NANO LETTERS 2023; 23:4579-4586. [PMID: 37154760 DOI: 10.1021/acs.nanolett.3c01044] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
Organic radicals have long been suggested as candidates for organic magnets and components in organic spintronic devices. Herein, we demonstrate spin current emission from an organic radical film via spin pumping at room temperature. We present the synthesis and the thin film preparation of a Blatter-type radical with outstanding stability and low roughness. These features enable the fabrication of a radical/ferromagnet bilayer, in which the spin current emission from the organic radical layer can be reversibly reduced when the ferromagnetic film is brought into simultaneous resonance with the radical. The results provide an experimental demonstration of a metal-free organic radical layer operating as a spin source, opening a new avenue for the development of purely organic spintronic devices and bridging the gap between potential and real applications.
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Affiliation(s)
| | - Fadwat Bazzi
- Department of Natural Sciences, University of Michigan - Dearborn, 4901 Evergreen Rd, Dearborn, Michigan 48128-1491, United States
| | - Evangelos Vouros
- Department of Physics, University of Cyprus, P.O. Box 20537, 1678 Nicosia, Cyprus
| | - Dragos F Flesariu
- Department of Chemistry, University of Cyprus, P.O. Box 20537, 1678 Nicosia, Cyprus
| | - Nicolas Chrysochos
- Department of Chemistry, University of Cyprus, P.O. Box 20537, 1678 Nicosia, Cyprus
| | | | - Christos P Constantinides
- Department of Natural Sciences, University of Michigan - Dearborn, 4901 Evergreen Rd, Dearborn, Michigan 48128-1491, United States
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Miao Y, Li D, Zhang H, Ren J, Hu G. Spin Hall effect from bipolaron dynamics in organics. Phys Chem Chem Phys 2023; 25:7763-7771. [PMID: 36857654 DOI: 10.1039/d2cp05204k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/15/2023]
Abstract
Using an extended Su-Schrieffer-Heeger model and a nonadiabatic dynamics method, we investigate the dynamics of bipolarons in coupled nondegenerate organic chains including the spin-orbit coupling and interchain coupling. By tracing the time-dependent evolution of the charges and spins in each chain, an obvious oscillating spin Hall effect (SHE) from the bipolaron transport is revealed. The results are compared with that from polaron-dominated transport. A reduction of amplitude and an increase of oscillating frequency are observed for the SHE from the bipolaron transport. The mechanism is attributed to the enhanced skew scattering off the larger transient deformations of the chains in the case of the bipolaron. Spectrum analysis by fast Fourier transform of the SHE signal demonstrates a distinct shift of two characteristic peaks to a higher onset frequency compared to the polaron transport. The charge-spin conversion efficiency is also compared, where a larger conversion efficiency is obtained from the bipolaron transport due to the lower saturated velocity. The effects of the strength of the electric field and the interactions are discussed. This work reveals the role of the bipolaron in organic SHE and provides a feasible way to achieve larger conversion efficiency by controlling the species of carriers with the concentration of the dopant.
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Affiliation(s)
- Yuanyuan Miao
- School of Physics and Electronics, Shandong Normal University, Jinan 250100, China.
| | - Dan Li
- School of Physics and Electronics, Shandong Normal University, Jinan 250100, China.
| | - Huiqing Zhang
- School of Physics and Electronics, Shandong Normal University, Jinan 250100, China.
| | - Junfeng Ren
- School of Physics and Electronics, Shandong Normal University, Jinan 250100, China.
| | - Guichao Hu
- School of Physics and Electronics, Shandong Normal University, Jinan 250100, China.
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Zhang L, Zan J, Huang Y, Cui H, Hao Y. Generating Pure Spin Current in Heterojunction Organic Solar Cells. J Phys Chem Lett 2021; 12:12114-12118. [PMID: 34913703 DOI: 10.1021/acs.jpclett.1c03569] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
We propose a mechanism for generating pure spin current in heterojunction organic solar cells, with the donor and acceptor both being degenerate ground-state polymers; thus, solitons can be formed. This mechanism contains the following steps: (i) the donor is photoexcited to create the electron-hole (e-h) pairs; (ii) the excited electrons are transferred to the acceptor; (iii) the net charges in the donor and acceptor are evolved into the localized charged solitons; (iv) the intermolecule bias is applied to drive the transferred electrons back to donor, and concomitantly, charged solitons are converted to neutral solitons. Here, the on-site Coulomb interaction plays an important role in ensuring the neutral solitons' spins in the donor and acceptor are oppositely polarized. Because spins are separated between the donor and acceptor without any charge separations, pure spin current can be formed. Our mechanism opens a new avenue for exploring potential organic spintronic devices.
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Affiliation(s)
- Longlong Zhang
- College of Physics and Optoelectronics, Taiyuan University of Technology, Taiyuan 030024, China
| | - Jun Zan
- College of Physics and Optoelectronics, Taiyuan University of Technology, Taiyuan 030024, China
| | - Yujuan Huang
- College of Physics and Optoelectronics, Taiyuan University of Technology, Taiyuan 030024, China
| | - Huiqin Cui
- College of Physics and Optoelectronics, Taiyuan University of Technology, Taiyuan 030024, China
| | - Yuying Hao
- College of Physics and Optoelectronics, Taiyuan University of Technology, Taiyuan 030024, China
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Lu Q, Xie S, Qu F. Hopping-Dominated Spin Transport in Unintentionally Doped Organic Semiconductors. J Phys Chem Lett 2021; 12:3540-3544. [PMID: 33797911 DOI: 10.1021/acs.jpclett.1c00692] [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 report a spin diffusion theory to predict unusual pure spin current transport in unintentionally doped organic semiconductors. We demonstrate that the feasibility of pure spin current transport via polaron hopping at a low carrier density. Our theoretical prediction, 40 nm, for spin diffusion length (SDL) in dinaphtho[2,3-b:2,3-f]thieno[3,2-b]thiophene (DNTT) is in very good agreement with experimental data. Interestingly, SDL can be prolonged by restraining molecular geometry structure disorder and reducing the reorganization energy. In comparison with anisotropic organic materials, the SDL in isotropic ones increases up to 60%. Our results open up a new avenue to design organic spintronics devices with long SDL and low carrier density.
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Affiliation(s)
- Qiuxia Lu
- School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100, China
| | - Shijie Xie
- School of Physics, State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100, China
| | - Fanyao Qu
- Institute of Physics, International Center for Condensed Matter Physics, University of Brasilia, Brasilia 70919-970, Brazil
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