101
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Gong SJ, Zheng F, Rappe AM. Phonon Influence on Bulk Photovoltaic Effect in the Ferroelectric Semiconductor GeTe. PHYSICAL REVIEW LETTERS 2018; 121:017402. [PMID: 30028160 DOI: 10.1103/physrevlett.121.017402] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2017] [Revised: 03/03/2018] [Indexed: 06/08/2023]
Abstract
The shift current (SHC) has been accepted as the primary mechanism of the bulk photovoltaic effect (BPVE) in ferroelectrics, which is much different from the typical p-n junction-based photovoltaic mechanism in heterogeneous materials. In the present work, we use first-principles calculations to investigate the SHC response in the ferroelectric semiconductor GeTe, which is found possess a large SHC response due to its intrinsic narrow band gap and high covalency. We explore the changes of SHC response induced by phonon vibrations, and analytically fit current versus vibrational amplitude to reveal the quantitative relationships between vibrations and the SHC response. Furthermore, we demonstrate the temperature dependence of the SHC response by averaging the phonon vibration influence in the Brillouin zone. Our investigation provides an explicit experimental prediction about the temperature dependence of BPVE and can be extended to other classes of noncentrosymmetric materials.
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Affiliation(s)
- Shi-Jing Gong
- Key Laboratory of Polar Materials and Devices, Ministry of Education, Department of Electronic Engineering, East China Normal University, Shanghai 200062, China
| | - Fan Zheng
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6323, USA
| | - Andrew M Rappe
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6323, USA
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102
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You L, Zheng F, Fang L, Zhou Y, Tan LZ, Zhang Z, Ma G, Schmidt D, Rusydi A, Wang L, Chang L, Rappe AM, Wang J. Enhancing ferroelectric photovoltaic effect by polar order engineering. SCIENCE ADVANCES 2018; 4:eaat3438. [PMID: 29984307 PMCID: PMC6035034 DOI: 10.1126/sciadv.aat3438] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2018] [Accepted: 05/24/2018] [Indexed: 05/31/2023]
Abstract
Ferroelectric materials for photovoltaics have sparked great interest because of their switchable photoelectric responses and above-bandgap photovoltages that violate conventional photovoltaic theory. However, their relatively low photocurrent and power conversion efficiency limit their potential application in solar cells. To improve performance, conventional strategies focus mainly on narrowing the bandgap to better match the solar spectrum, leaving the fundamental connection between polar order and photovoltaic effect largely overlooked. We report large photovoltaic enhancement by A-site substitutions in a model ferroelectric photovoltaic material, BiFeO3. As revealed by optical measurements and supported by theoretical calculations, the enhancement is accompanied by the chemically driven rotational instability of the polarization, which, in turn, affects the charge transfer at the band edges and drives a direct-to-indirect bandgap transition, highlighting the strong coupling between polarization, lattice, and orbital order parameters in ferroelectrics. Polar order engineering thus provides an additional degree of freedom to further boost photovoltaic efficiency in ferroelectrics and related materials.
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Affiliation(s)
- Lu You
- School of Materials Science and Engineering, Nanyang Technological University, Singapore 639798, Singapore
| | - Fan Zheng
- Department of Chemistry, University of Pennsylvania, Philadelphia, PA 19104−6323, USA
| | - Liang Fang
- Jiangsu Key Laboratory of Thin Films and Department of Physics, Soochow University, Suzhou 215006, China
| | - Yang Zhou
- School of Materials Science and Engineering, Nanyang Technological University, Singapore 639798, Singapore
| | - Liang Z. Tan
- Department of Chemistry, University of Pennsylvania, Philadelphia, PA 19104−6323, USA
| | - Zeyu Zhang
- Department of Physics, Shanghai University, Shanghai 200444, China
| | - Guohong Ma
- Department of Physics, Shanghai University, Shanghai 200444, China
| | - Daniel Schmidt
- Singapore Synchrotron Light Source, National University of Singapore, 5 Research Link, Singapore 117603, Singapore
| | - Andrivo Rusydi
- Singapore Synchrotron Light Source, National University of Singapore, 5 Research Link, Singapore 117603, Singapore
| | - Le Wang
- School of Materials Science and Engineering, Nanyang Technological University, Singapore 639798, Singapore
| | - Lei Chang
- School of Materials Science and Engineering, Nanyang Technological University, Singapore 639798, Singapore
| | - Andrew M. Rappe
- Department of Chemistry, University of Pennsylvania, Philadelphia, PA 19104−6323, USA
| | - Junling Wang
- School of Materials Science and Engineering, Nanyang Technological University, Singapore 639798, Singapore
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103
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Electron-hole separation in ferroelectric oxides for efficient photovoltaic responses. Proc Natl Acad Sci U S A 2018; 115:6566-6571. [PMID: 29891684 PMCID: PMC6042087 DOI: 10.1073/pnas.1721503115] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Photovoltaics (PVs) benefitting from ferroelectric polarizations can overcome critical limitations of conventional type PVs. In this class, Bi2FeCrO6 is known to be the best-performing material; however, a fundamental understanding of the origin is lacking, which has limited further performance improvements. Here, we carried out a theoretical investigation of the electronic structure of this material. As a result, electron−hole (e-h) pairs are observed to separate upon photoexcitation, which can be a dominant underlying mechanism for the exceptional PV responses. Based on this understanding, we further suggest five novel materials that can offer a combination of strong e-h separations and visible-light absorptions. We expect the community of ferroelectric PVs to immediately benefit from the features of the new suggested materials. Despite their potential to exceed the theoretical Shockley−Queisser limit, ferroelectric photovoltaics (FPVs) have performed inefficiently due to their extremely low photocurrents. Incorporating Bi2FeCrO6 (BFCO) as the light absorber in FPVs has recently led to impressively high and record photocurrents [Nechache R, et al. (2015) Nat Photonics 9:61–67], which has revived the FPV field. However, our understanding of this remarkable phenomenon is far from satisfactory. Here, we use first-principles calculations to determine that such excellent performance mainly lies in the efficient separation of electron−hole (e-h) pairs. We show that photoexcited electrons and holes in BFCO are spatially separated on the Fe and Cr sites, respectively. This separation is much more pronounced in disordered BFCO phases, which adequately explains the observed exceptional PV responses. We further establish a design strategy to discover next-generation FPV materials. By exploring 44 additional Bi-based double-perovskite oxides, we suggest five active-layer materials that offer a combination of strong e-h separations and visible-light absorptions for FPV applications. Our work indicates that charge separation is the most important issue to be addressed for FPVs to compete with conventional devices.
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104
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Qi J, Ma N, Ma X, Adelung R, Yang Y. Enhanced Photocurrent in BiFeO 3 Materials by Coupling Temperature and Thermo-Phototronic Effects for Self-Powered Ultraviolet Photodetector System. ACS APPLIED MATERIALS & INTERFACES 2018; 10:13712-13719. [PMID: 29619823 DOI: 10.1021/acsami.8b02543] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Ferroelectric materials can be utilized for fabricating photodetectors because of the photovoltaic effect. Enhancing the photovoltaic performance of ferroelectric materials is still a challenge. Here, a self-powered ultraviolet (UV) photodetector is designed based on the ferroelectric BiFeO3 (BFO) material, exhibiting a high current/voltage response to 365 nm light in heating/cooling states. The photovoltaic performance of the BFO-based device can be well modulated by applying different temperature variations, where the output current and voltage can be enhanced by 60 and 75% in heating and cooling states, respectively. The enhancement mechanism of the photocurrent is associated with both temperature effect and thermo-phototronic effect in the photovoltaic process. Moreover, a 4 × 4 matrix photodetector array has been designed for detecting the 365 nm light distribution in the cooling state by utilizing photovoltage signals. This study clarifies the role of the temperature effect and the thermo-phototronic effect in the photovoltaic process of the BFO material and provides a feasible route for pushing forward practical applications of self-powered UV photodetectors.
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Affiliation(s)
- Jia Qi
- CAS Center for Excellence in Nanoscience, Beijing Institute of Nanoenergy and Nanosystems , Chinese Academy of Sciences , Beijing 100083 , China
- School of Nanoscience and Technology , University of Chinese Academy of Sciences , Beijing 100049 , China
| | - Nan Ma
- CAS Center for Excellence in Nanoscience, Beijing Institute of Nanoenergy and Nanosystems , Chinese Academy of Sciences , Beijing 100083 , China
- School of Nanoscience and Technology , University of Chinese Academy of Sciences , Beijing 100049 , China
| | - Xiaochen Ma
- CAS Center for Excellence in Nanoscience, Beijing Institute of Nanoenergy and Nanosystems , Chinese Academy of Sciences , Beijing 100083 , China
- School of Nanoscience and Technology , University of Chinese Academy of Sciences , Beijing 100049 , China
| | - Rainer Adelung
- Functional Nanomaterials, Institute for Materials Science , Kiel University , Kaiserstr. 2 , D-24143 Kiel , Germany
| | - Ya Yang
- CAS Center for Excellence in Nanoscience, Beijing Institute of Nanoenergy and Nanosystems , Chinese Academy of Sciences , Beijing 100083 , China
- School of Nanoscience and Technology , University of Chinese Academy of Sciences , Beijing 100049 , China
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105
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Yang MM, Kim DJ, Alexe M. Flexo-photovoltaic effect. Science 2018; 360:904-907. [DOI: 10.1126/science.aan3256] [Citation(s) in RCA: 171] [Impact Index Per Article: 28.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2017] [Accepted: 04/06/2018] [Indexed: 01/24/2023]
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106
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Yang MM, Alexe M. Light-Induced Reversible Control of Ferroelectric Polarization in BiFeO 3. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2018; 30:e1704908. [PMID: 29457305 DOI: 10.1002/adma.201704908] [Citation(s) in RCA: 67] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/27/2017] [Revised: 12/22/2017] [Indexed: 06/08/2023]
Abstract
Manipulation of ferroic order parameters, namely (anti-)ferromagnetic, ferroelectric, and ferroelastic, by light at room temperature is a fascinating topic in modern solid-state physics due to potential cross-fertilization in research fields that are largely decoupled. Here, full optical control, that is, reversible switching, of the ferroelectric/ferroelastic domains in BiFeO3 thin films at room temperature by the mediation of the tip-enhanced photovoltaic effect is demonstrated. The enhanced short-circuit photocurrent density at the tip contact area generates a local electric field well exceeding the coercive field, enabling ferroelectric polarization switching. Interestingly, by tailoring the photocurrent direction, via either tuning the illumination geometry or simply rotating the light polarization, full control of the ferroelectric polarization is achieved. The finding offers a new insight into the interactions between light and ferroic orders, enabling fully optical control of all the ferroic orders at room temperature and providing guidance to design novel optoferroic devices for data storage and sensing.
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Affiliation(s)
- Ming-Min Yang
- Department of Physics, The University of Warwick, Coventry, CV4 7AL, UK
| | - Marin Alexe
- Department of Physics, The University of Warwick, Coventry, CV4 7AL, UK
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107
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Yang X, Zeng R, Ren Z, Wu Y, Chen X, Li M, Chen J, Zhao R, Zhou D, Liao Z, Tian H, Lu Y, Li X, Li J, Han G. Single-Crystal BiFeO 3 Nanoplates with Robust Antiferromagnetism. ACS APPLIED MATERIALS & INTERFACES 2018; 10:5785-5792. [PMID: 29368504 DOI: 10.1021/acsami.7b17449] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Freestanding and single-crystal BiFeO3 (BFO) nanoplates have been successfully synthesized by a fluoride ion-assisted hydrothermal method, and the thickness of the nanoplates can be effectively tailored from 80 to 380 nm by the concentration of fluoride ions. It is revealed that BFO nanoplates grew via an oriented attachment of layer by layer, giving rise to the formation of the inner interface within the nanoplates. In particular, antiferromagnetic (AFM) phase-transition temperature (Néel temperature, TN) of the BFO nanoplates is significantly enhanced from typical 370 to ∼512 °C, whereas the Curie temperature (TC) of the BFO nanoplates is determined to be ∼830 °C, in good agreement with a bulk value. The combination of scanning transmission electron microscopy, electron energy loss spectroscopy, and the first-principle calculations reveals that the interfacial tensile strain remarkably improves the stability of AFM ordering, accounting for the significant enhancement in TN of BFO plates. Correspondingly, the tensile strain induced the polarization and oxygen octahedral tilting has been observed near the interface. The findings presented here suggest that single-crystal BFO nanoplate is an ideal system for exploring an intrinsic magnetoelectric property, where a tensile strain can be a very promising approach to tailor AFM ordering and polarization rotation for an enhanced coupling effect.
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Affiliation(s)
- Xin Yang
- State Key Laboratory of Silicon Materials, School of Materials Science and Engineering, Cyrus Tang Center for Sensor Materials and Application, Zhejiang University , Hangzhou 310027, China
- Key Laboratory of Advanced Technique & Preparation for Renewable Energy Materials, Ministry of Education, Yunnan Normal University , Kunming 650500, China
| | - RongGuang Zeng
- Science and Technology on Surface Physics and Chemistry Laboratory , P.O. Box 718-35, Mianyang 621907, China
| | - ZhaoHui Ren
- State Key Laboratory of Silicon Materials, School of Materials Science and Engineering, Cyrus Tang Center for Sensor Materials and Application, Zhejiang University , Hangzhou 310027, China
| | - YanFei Wu
- Institute for Quantum Science and Engineering and Department of Physics, South University of Science and Technology of China , Shenzhen 518055, China
| | - Xing Chen
- Center of Electron Microscope, School of Materials Science and Engineering, Zhejiang University , Hangzhou 310027, China
| | - Ming Li
- State Key Laboratory of Silicon Materials, School of Materials Science and Engineering, Cyrus Tang Center for Sensor Materials and Application, Zhejiang University , Hangzhou 310027, China
| | - JiaLu Chen
- State Key Laboratory of Silicon Materials, School of Materials Science and Engineering, Cyrus Tang Center for Sensor Materials and Application, Zhejiang University , Hangzhou 310027, China
| | - RuoYu Zhao
- State Key Laboratory of Silicon Materials, School of Materials Science and Engineering, Cyrus Tang Center for Sensor Materials and Application, Zhejiang University , Hangzhou 310027, China
| | - DiKui Zhou
- State Key Laboratory of Silicon Materials, School of Materials Science and Engineering, Cyrus Tang Center for Sensor Materials and Application, Zhejiang University , Hangzhou 310027, China
| | - ZhiMin Liao
- State Key Laboratory for Mesoscopic Physics, School of Physics, Peking University , Beijing 100871, China
| | - He Tian
- Center of Electron Microscope, School of Materials Science and Engineering, Zhejiang University , Hangzhou 310027, China
| | - YunHao Lu
- State Key Laboratory of Silicon Materials, School of Materials Science and Engineering, Cyrus Tang Center for Sensor Materials and Application, Zhejiang University , Hangzhou 310027, China
| | - Xiang Li
- State Key Laboratory of Silicon Materials, School of Materials Science and Engineering, Cyrus Tang Center for Sensor Materials and Application, Zhejiang University , Hangzhou 310027, China
| | - JiXue Li
- Center of Electron Microscope, School of Materials Science and Engineering, Zhejiang University , Hangzhou 310027, China
| | - GaoRong Han
- State Key Laboratory of Silicon Materials, School of Materials Science and Engineering, Cyrus Tang Center for Sensor Materials and Application, Zhejiang University , Hangzhou 310027, China
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108
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Han H, Kim D, Chu K, Park J, Nam SY, Heo S, Yang CH, Jang HM. Enhanced Switchable Ferroelectric Photovoltaic Effects in Hexagonal Ferrite Thin Films via Strain Engineering. ACS APPLIED MATERIALS & INTERFACES 2018; 10:1846-1853. [PMID: 29250953 DOI: 10.1021/acsami.7b16700] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Ferroelectric photovoltaics (FPVs) are being extensively investigated by virtue of switchable photovoltaic responses and anomalously high photovoltages of ∼104 V. However, FPVs suffer from extremely low photocurrents due to their wide band gaps (Eg). Here, we present a promising FPV based on hexagonal YbFeO3 (h-YbFO) thin-film heterostructure by exploiting its narrow Eg. More importantly, we demonstrate enhanced FPV effects by suitably exploiting the substrate-induced film strain in these h-YbFO-based photovoltaics. A compressive-strained h-YbFO/Pt/MgO heterojunction device shows ∼3 times enhanced photovoltaic efficiency than that of a tensile-strained h-YbFO/Pt/Al2O3 device. We have shown that the enhanced photovoltaic efficiency mainly stems from the enhanced photon absorption over a wide range of the photon energy, coupled with the enhanced polarization under a compressive strain. Density functional theory studies indicate that the compressive strain reduces Eg substantially and enhances the strength of d-d transitions. This study will set a new standard for determining substrates toward thin-film photovoltaics and optoelectronic devices.
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Affiliation(s)
- Hyeon Han
- Department of Materials Science and Engineering and Division of Advanced Materials Science, Pohang University of Science and Technology (POSTECH) , Pohang 37673, Republic of Korea
| | - Donghoon Kim
- Department of Materials Science and Engineering and Division of Advanced Materials Science, Pohang University of Science and Technology (POSTECH) , Pohang 37673, Republic of Korea
| | - Kanghyun Chu
- Department of Physics, Korea Advanced Institute of Science and Technology (KAIST) , Daejeon 343411, Republic of Korea
| | - Jucheol Park
- Gyeongbuk Science & Technology Promotion Center, Gumi Electronics & Information Technology Research Institute , Gumi 39171, Republic of Korea
| | - Sang Yeol Nam
- Gyeongbuk Science & Technology Promotion Center, Gumi Electronics & Information Technology Research Institute , Gumi 39171, Republic of Korea
- Department of Materials Science and Engineering, Kumoh National Institute of Technology , Gumi 39177, Republic of Korea
| | - Seungyang Heo
- Department of Materials Science and Engineering and Division of Advanced Materials Science, Pohang University of Science and Technology (POSTECH) , Pohang 37673, Republic of Korea
| | - Chan-Ho Yang
- Department of Physics, Korea Advanced Institute of Science and Technology (KAIST) , Daejeon 343411, Republic of Korea
- KAIST Institute for the Nano Century , Daejeon 343411, Republic of Korea
| | - Hyun Myung Jang
- Department of Materials Science and Engineering and Division of Advanced Materials Science, Pohang University of Science and Technology (POSTECH) , Pohang 37673, Republic of Korea
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109
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Ma N, Zhang K, Yang Y. Photovoltaic-Pyroelectric Coupled Effect Induced Electricity for Self-Powered Photodetector System. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2017; 29:1703694. [PMID: 29058793 DOI: 10.1002/adma.201703694] [Citation(s) in RCA: 63] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2017] [Revised: 09/04/2017] [Indexed: 05/25/2023]
Abstract
Ferroelectric materials have demonstrated novel photovoltaic effect to scavenge solar energy. However, most of the ferroelectric materials with wide bandgaps (2.7-4 eV) suffer from low power conversion efficiency of less than 0.5% due to absorbing only 8-20% of solar spectrum. Instead of harvesting solar energy, these ferroelectric materials can be well suited for photodetector applications, especially for sensing near-UV irradiations. Here, a ferroelectric BaTiO3 film-based photodetector is demonstrated that can be operated without using any external power source and a fast sensing of 405 nm light illumination is enabled. As compared with photovoltaic effect, both the responsivity and the specific detectivity of the photodetector can be dramatically enhanced by larger than 260% due to the light-induced photovoltaic-pyroelectric coupled effect. A self-powered photodetector array system can be utilized to achieve spatially resolved light intensity detection by recording the output voltage signals as a mapping figure.
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Affiliation(s)
- Nan Ma
- Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Sciences, Beijing, 100083, P. R. China
- CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology (NCNST), Beijing, 100190, P. R. China
| | - Kewei Zhang
- Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Sciences, Beijing, 100083, P. R. China
- CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology (NCNST), Beijing, 100190, P. R. China
| | - Ya Yang
- Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Sciences, Beijing, 100083, P. R. China
- CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology (NCNST), Beijing, 100190, P. R. China
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110
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Shenton JK, Bowler DR, Cheah WL. Effects of the Hubbard U on density functional-based predictions of BiFeO 3 properties. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2017; 29:445501. [PMID: 28853713 DOI: 10.1088/1361-648x/aa8935] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
First principles studies of multiferroic materials, such as bismuth ferrite (BFO), require methods that extend beyond standard density functional theory (DFT). The DFT + U method is one such extension that is widely used in the study of BFO. We present a systematic study of the effects of the U parameter on the structural, ferroelectric and electronic properties of BFO. We find that the structural and ferroelectric properties change negligibly in the range of U typically considered for BFO (3-5 eV). In contrast, the electronic structure varies significantly with U. In particular, we see large changes to the character and curvature of the valence band maximum and conduction band minimum, in addition to the expected increase in band gap, as U increases. Most significantly, we find that the [Formula: see text]/[Formula: see text] ordering at the conduction band minimum inverts for U values larger than 4 eV. We therefore recommend a U value of at most 4 eV to be applied to the Fe d orbitals in BFO. More generally, this study emphasises the need for systematic investigations of the effects of the U parameter not merely on band gaps but on the electronic structure as a whole, especially for strongly correlated materials.
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Affiliation(s)
- J Kane Shenton
- Department of Physics & Astronomy, University College London, Gower St, London WC1E 6BT, United Kingdom. Institute of High Performance Computing, 1 Fusionopolis Way, #16-16 Connexis North, 138632, Singapore. London Centre for Nanotechnology, 17-19 Gordon St, London WC1H 0AH, United Kingdom
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111
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Lu Z, Li P, Wan JG, Huang Z, Tian G, Pan D, Fan Z, Gao X, Liu JM. Controllable Photovoltaic Effect of Microarray Derived from Epitaxial Tetragonal BiFeO 3 Films. ACS APPLIED MATERIALS & INTERFACES 2017; 9:27284-27289. [PMID: 28745480 DOI: 10.1021/acsami.7b06535] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Recently, the ferroelectric photovoltaic (FePV) effect has attracted great interest due to its potential in developing optoelectronic devices such as solar cell and electric-optical sensors. It is important for actual applications to realize a controllable photovoltaic process in ferroelectric-based materials. In this work, we prepared well-ordered microarrays based on epitaxially tetragonal BiFeO3 (T-BFO) films by the pulsed laser deposition technique. The polarization-dependent photocurrent image was directly observed by a conductive atomic force microscope under ultraviolet illumination. By choosing a suitable buffer electrode layer and controlling the ferroelectric polarization in the T-BFO layer, we realized the manipulation of the photovoltaic process. Moreover, based on the analysis of the band structure, we revealed the mechanism of manipulating the photovoltaic process and attributed it to the competition between two key factors, i.e., the internal electric field caused by energy band alignments at interfaces and the depolarization field induced by the ferroelectric polarization in T-BFO. This work is very meaningful for deeply understanding the photovoltaic process of BiFeO3-based devices at the microscale and provides us a feasible avenue for developing data storage or logic switching microdevices based on the FePV effect.
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Affiliation(s)
- Zengxing Lu
- Laboratory of Solid State Microstructures and Innovation Center of Advanced Microstructures, Nanjing University , Nanjing 210093, China
| | - Peilian Li
- Institute for Advanced Materials and Laboratory of Quantum Engineering and Quantum Materials, South China Normal University , Guangzhou 510006, China
| | - Jian-Guo Wan
- Laboratory of Solid State Microstructures and Innovation Center of Advanced Microstructures, Nanjing University , Nanjing 210093, China
| | - Zhifeng Huang
- Institute for Advanced Materials and Laboratory of Quantum Engineering and Quantum Materials, South China Normal University , Guangzhou 510006, China
| | - Guo Tian
- Institute for Advanced Materials and Laboratory of Quantum Engineering and Quantum Materials, South China Normal University , Guangzhou 510006, China
| | - Danfeng Pan
- Laboratory of Solid State Microstructures and Innovation Center of Advanced Microstructures, Nanjing University , Nanjing 210093, China
| | - Zhen Fan
- Institute for Advanced Materials and Laboratory of Quantum Engineering and Quantum Materials, South China Normal University , Guangzhou 510006, China
| | - Xingsen Gao
- Institute for Advanced Materials and Laboratory of Quantum Engineering and Quantum Materials, South China Normal University , Guangzhou 510006, China
| | - Jun-Ming Liu
- Laboratory of Solid State Microstructures and Innovation Center of Advanced Microstructures, Nanjing University , Nanjing 210093, China
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112
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Gap-state engineering of visible-light-active ferroelectrics for photovoltaic applications. Nat Commun 2017; 8:207. [PMID: 28785049 PMCID: PMC5547143 DOI: 10.1038/s41467-017-00245-9] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2017] [Accepted: 06/12/2017] [Indexed: 11/08/2022] Open
Abstract
Photoferroelectrics offer unique opportunities to explore light energy conversion based on their polarization-driven carrier separation and above-bandgap voltages. The problem associated with the wide bandgap of ferroelectric oxides, i.e., the vanishingly small photoresponse under visible light, has been overcome partly by bandgap tuning, but the narrowing of the bandgap is, in principle, accompanied by a substantial loss of ferroelectric polarization. In this article, we report an approach, ‘gap-state’ engineering, to produce photoferroelectrics, in which defect states within the bandgap act as a scaffold for photogeneration. Our first-principles calculations and single-domain thin-film experiments of BiFeO3 demonstrate that gap states half-filled with electrons can enhance not only photocurrents but also photovoltages over a broad photon-energy range that is different from intermediate bands in present semiconductor-based solar cells. Our approach opens a promising route to the material design of visible-light-active ferroelectrics without sacrificing spontaneous polarization. Overcoming the optical transparency of wide bandgap of ferroelectric oxides by narrowing its bandgap tends to result in a loss of polarization. By utilizing defect states within the bandgap, Matsuo et al. report visible-light-active ferroelectrics without sacrificing polarization.
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113
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Nagaosa N, Morimoto T. Concept of Quantum Geometry in Optoelectronic Processes in Solids: Application to Solar Cells. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2017; 29:1603345. [PMID: 28318063 DOI: 10.1002/adma.201603345] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/2016] [Revised: 11/21/2016] [Indexed: 06/06/2023]
Abstract
The concept of topology is becoming more and more relevant to the properties and functions of electronic materials including various transport phenomena and optical responses. A pedagogical introduction is given here to the basic ideas and their applications to optoelectronic processes in solids.
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Affiliation(s)
- Naoto Nagaosa
- RIKEN Center for Emergent Matter Science (CEMS), Wako, Saitama, 351-0198, Japan
- Department of Applied Physics, The University of Tokyo, Tokyo, 113-8656, Japan
| | - Takahiro Morimoto
- Department of Physics, University of California, Berkeley, CA, 94720, USA
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114
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Liu S, Cohen RE. Stable charged antiparallel domain walls in hyperferroelectrics. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2017; 29:244003. [PMID: 28443824 DOI: 10.1088/1361-648x/aa6f95] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Charge-neutral 180° domain walls that separate domains of antiparallel polarization directions are common structural topological defects in ferroelectrics. In normal ferroelectrics, charged 180° domain walls running perpendicular to the polarization directions are highly energetically unfavorable because of the depolarization field and are difficult to stabilize. We explore both neutral and charged 180° domain walls in hyperferroelectrics, a class of proper ferroelectrics with persistent polarization in the presence of a depolarization field, using density functional theory. We obtain zero temperature equilibrium structures of head-to-head and tail-to-tail walls in recently discovered ABC-type hexagonal hyperferroelectrics. Charged domain walls can also be stabilized in canonical ferroelectrics represented by LiNbO3 without any dopants, defects or mechanical clamping. First-principles electronic structure calculations show that charged domain walls can reduce and even close the band gap of host materials and support quasi-two-dimensional electron(hole) gas with enhanced electrical conductivity.
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Affiliation(s)
- S Liu
- Extreme Materials Initiative, Geophysical Laboratory, Carnegie Institution for Science, Washington, DC 20015-1305, United States of America
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115
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Ren Y, Nan F, You L, Zhou Y, Wang Y, Wang J, Su X, Shen M, Fang L. Enhanced Photoelectrochemical Performance in Reduced Graphene Oxide/BiFeO 3 Heterostructures. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2017; 13:1603457. [PMID: 28181404 DOI: 10.1002/smll.201603457] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2016] [Revised: 01/10/2017] [Indexed: 06/06/2023]
Abstract
BiFeO3 (BFO)-based ferroelectrics have been proved to be visible-light-driven photoelectrodes for O2 production. However, the hitherto reported photoelectrochemical performances remain inferior to meet the requirements for any applications. Besides, expensive noble metals (Ag, Au) are commonly required to achieve high photoelectric conversion efficiency. Here, the significant enhancements of photoelectrochemical performance is reported by fabricating a noble-metal-free reduced graphene oxide (RGO)/BFO composite film via a simple and cost-effective solution process. The optimized RGO/BFO composite film exhibits a 600% improvement of the short-circuit photocurrent density compared to that of the pristine BFO, and also outperforms the noble-metal/BFO cells under the same reaction conditions. Furthermore, the incident photon-to-current efficiency of the optimized RGO/BFO sample shows threefold enhancement. This study delivers a facile and low-cost approach to preparing 2D materials/ferroelectric heterostructures and offers a promising pathway to boost the performance of semiconducting ferroelectric photoelectrodes.
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Affiliation(s)
- Yan Ren
- College of Physics, Optoelectronics and Energy and Jiangsu Key Laboratory of Thin Films, Soochow University, Suzhou, 215006, P. R. China
| | - Feng Nan
- College of Physics, Optoelectronics and Energy and Jiangsu Key Laboratory of Thin Films, Soochow University, Suzhou, 215006, P. R. China
| | - Lu You
- School of Materials Science and Engineering, Nanyang Technological University, Singapore, 639798, Singapore
| | - Yang Zhou
- School of Materials Science and Engineering, Nanyang Technological University, Singapore, 639798, Singapore
| | - Yanyan Wang
- College of Physics, Optoelectronics and Energy and Jiangsu Key Laboratory of Thin Films, Soochow University, Suzhou, 215006, P. R. China
| | - Junling Wang
- School of Materials Science and Engineering, Nanyang Technological University, Singapore, 639798, Singapore
| | - Xiaodong Su
- College of Physics, Optoelectronics and Energy and Jiangsu Key Laboratory of Thin Films, Soochow University, Suzhou, 215006, P. R. China
| | - Mingrong Shen
- College of Physics, Optoelectronics and Energy and Jiangsu Key Laboratory of Thin Films, Soochow University, Suzhou, 215006, P. R. China
| | - Liang Fang
- College of Physics, Optoelectronics and Energy and Jiangsu Key Laboratory of Thin Films, Soochow University, Suzhou, 215006, P. R. China
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116
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Gu Z, Imbrenda D, Bennett-Jackson AL, Falmbigl M, Podpirka A, Parker TC, Shreiber D, Ivill MP, Fridkin VM, Spanier JE. Mesoscopic Free Path of Nonthermalized Photogenerated Carriers in a Ferroelectric Insulator. PHYSICAL REVIEW LETTERS 2017; 118:096601. [PMID: 28306282 DOI: 10.1103/physrevlett.118.096601] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2016] [Indexed: 06/06/2023]
Abstract
We show how finite-size scaling of a bulk photovoltaic effect-generated electric field in epitaxial ferroelectric insulating BaTiO_{3}(001) films and a photo-Hall response involving the bulk photovoltaic current reveal a large room-temperature mean free path of photogenerated nonthermalized electrons. Experimental determination of mesoscopic ballistic optically generated carrier transport opens a new paradigm for hot electron-based solar energy conversion, and for facile control of ballistic transport distinct from existing low-dimensional semiconductor interfaces, surfaces, layers, or other structures.
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Affiliation(s)
- Zongquan Gu
- Department of Electrical and Computer Engineering, Drexel University, Philadelphia, Pennsylvania 19104, USA
| | - Dominic Imbrenda
- Department of Electrical and Computer Engineering, Drexel University, Philadelphia, Pennsylvania 19104, USA
| | - Andrew L Bennett-Jackson
- Department of Materials Science and Engineering, Drexel University, Philadelphia, Pennsylvania 19104, USA
| | - Matthias Falmbigl
- Department of Materials Science and Engineering, Drexel University, Philadelphia, Pennsylvania 19104, USA
| | - Adrian Podpirka
- Department of Materials Science and Engineering, Drexel University, Philadelphia, Pennsylvania 19104, USA
| | - Thomas C Parker
- U.S. Army Research Laboratory, Aberdeen Proving Ground, Maryland 21005, USA
| | - Daniel Shreiber
- U.S. Army Research Laboratory, Aberdeen Proving Ground, Maryland 21005, USA
| | - Mathew P Ivill
- U.S. Army Research Laboratory, Aberdeen Proving Ground, Maryland 21005, USA
| | - Vladimir M Fridkin
- Shubnikov Institute of Crystallography, Russian Academy of Sciences, Leninsky Prospect 59, Moscow 117333, Russian Federation
| | - Jonathan E Spanier
- Department of Materials Science and Engineering, Drexel University, Philadelphia, Pennsylvania 19104, USA
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117
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Yang MM, Bhatnagar A, Luo ZD, Alexe M. Enhancement of Local Photovoltaic Current at Ferroelectric Domain Walls in BiFeO 3. Sci Rep 2017; 7:43070. [PMID: 28216672 PMCID: PMC5380211 DOI: 10.1038/srep43070] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2016] [Accepted: 01/18/2017] [Indexed: 11/09/2022] Open
Abstract
Domain walls, which are intrinsically two dimensional nano-objects exhibiting nontrivial electronic and magnetic behaviours, have been proven to play a crucial role in photovoltaic properties of ferroelectrics. Despite this recognition, the electronic properties of domain walls under illumination until now have been accessible only to macroscopic studies and their effects upon the conduction of photovoltaic current still remain elusive. The lack of understanding hinders the developing of nanoscale devices based on ferroelectric domain walls. Here, we directly characterize the local photovoltaic and photoconductive properties of 71° domain walls on BiFeO3 thin films with a nanoscale resolution. Local photovoltaic current, proven to be driven by the bulk photovoltaic effect, has been probed over the whole illuminated surface by using a specially designed photoelectric atomic force microscopy and found to be significantly enhanced at domain walls. Additionally, spatially resolved photoconductive current distribution reveals a higher density of excited carriers at domain walls in comparison with domains. Our measurements demonstrate that domain wall enhanced photovoltaic current originates from its high conduction rather than the internal electric field. This photoconduction facilitated local photovoltaic current is likely to be a universal property of topological defects in ferroelectric semiconductors.
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Affiliation(s)
- Ming-Min Yang
- Department of Physics, University of Warwick, Coventry, CV4 7AL, United Kingdom
| | - Akash Bhatnagar
- Department of Physics, University of Warwick, Coventry, CV4 7AL, United Kingdom.,Centre for Innovation Competence SiLi-Nano, Karl-Freiherr-von-Fritsch-Straße 3, D-06120 Halle (Saale), Germany
| | - Zheng-Dong Luo
- Department of Physics, University of Warwick, Coventry, CV4 7AL, United Kingdom
| | - Marin Alexe
- Department of Physics, University of Warwick, Coventry, CV4 7AL, United Kingdom
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118
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Chen D, Chen Z, He Q, Clarkson JD, Serrao CR, Yadav AK, Nowakowski ME, Fan Z, You L, Gao X, Zeng D, Chen L, Borisevich AY, Salahuddin S, Liu JM, Bokor J. Interface Engineering of Domain Structures in BiFeO 3 Thin Films. NANO LETTERS 2017; 17:486-493. [PMID: 27935317 DOI: 10.1021/acs.nanolett.6b04512] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
A wealth of fascinating phenomena have been discovered at the BiFeO3 domain walls, examples such as domain wall conductivity, photovoltaic effects, and magnetoelectric coupling. Thus, the ability to precisely control the domain structures and accurately study their switching behaviors is critical to realize the next generation of novel devices based on domain wall functionalities. In this work, the introduction of a dielectric layer leads to the tunability of the depolarization field both in the multilayers and superlattices, which provides a novel approach to control the domain patterns of BiFeO3 films. Moreover, we are able to study the switching behavior of the first time obtained periodic 109° stripe domains with a thick bottom electrode. Besides, the precise controlling of pure 71° and 109° periodic stripe domain walls enable us to make a clear demonstration that the exchange bias in the ferromagnet/BiFeO3 system originates from 109° domain walls. Our findings provide future directions to study the room temperature electric field control of exchange bias and open a new pathway to explore the room temperature multiferroic vortices in the BiFeO3 system.
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Affiliation(s)
- Deyang Chen
- Institute for Advanced Materials and Guangdong Provincial Key Laboratory of Quantum Engineering and Quantum Materials, South China Normal University , Guangzhou 510006, China
- Department of Materials Science and Engineering, University of California, Berkeley , Berkeley, California 94720, United States
- School of Materials Science and Engineering, South China University of Technology , Guangzhou 510640, China
- Department of Physics, University of California Berkeley , Berkeley, California 94720, United States
| | - Zuhuang Chen
- Department of Materials Science and Engineering, University of California, Berkeley , Berkeley, California 94720, United States
| | - Qian He
- Materials Science and Technology Division, Oak Ridge National Laboratory , Oak Ridge, Tennessee 37831, United States
| | - James D Clarkson
- Department of Materials Science and Engineering, University of California, Berkeley , Berkeley, California 94720, United States
| | - Claudy R Serrao
- Department of Electrical Engineering and Computer Sciences, University of California Berkeley , Berkeley, California 94720, United States
| | - Ajay K Yadav
- Department of Materials Science and Engineering, University of California, Berkeley , Berkeley, California 94720, United States
| | - Mark E Nowakowski
- Department of Electrical Engineering and Computer Sciences, University of California Berkeley , Berkeley, California 94720, United States
| | - Zhen Fan
- Institute for Advanced Materials and Guangdong Provincial Key Laboratory of Quantum Engineering and Quantum Materials, South China Normal University , Guangzhou 510006, China
| | - Long You
- School of Optical and Electronic Information, Huazhong University of Science and Technology , Wuhan 430074, China
| | - Xingsen Gao
- Institute for Advanced Materials and Guangdong Provincial Key Laboratory of Quantum Engineering and Quantum Materials, South China Normal University , Guangzhou 510006, China
| | - Dechang Zeng
- School of Materials Science and Engineering, South China University of Technology , Guangzhou 510640, China
| | - Lang Chen
- Department of Physics, South University of Science and Technology of China , Shenzhen 518055, China
| | - Albina Y Borisevich
- Materials Science and Technology Division, Oak Ridge National Laboratory , Oak Ridge, Tennessee 37831, United States
| | - Sayeef Salahuddin
- Department of Electrical Engineering and Computer Sciences, University of California Berkeley , Berkeley, California 94720, United States
| | - Jun-Ming Liu
- Institute for Advanced Materials and Guangdong Provincial Key Laboratory of Quantum Engineering and Quantum Materials, South China Normal University , Guangzhou 510006, China
- Laboratory of Solid State Microstructures and Innovation Center of Advanced Microstructures, Nanjing University , Nanjing 210093, China
| | - Jeffrey Bokor
- Department of Electrical Engineering and Computer Sciences, University of California Berkeley , Berkeley, California 94720, United States
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119
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Wang L, Ma H, Chang L, Ma C, Yuan G, Wang J, Wu T. Ferroelectric BiFeO 3 as an Oxide Dye in Highly Tunable Mesoporous All-Oxide Photovoltaic Heterojunctions. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2017; 13:1602355. [PMID: 27706914 DOI: 10.1002/smll.201602355] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2016] [Revised: 08/30/2016] [Indexed: 06/06/2023]
Abstract
As potential photovoltaic materials, transition-metal oxides such as BiFeO3 (BFO) are capable of absorbing a substantial portion of solar light and incorporating ferroic orders into solar cells with enhanced performance. But the photovoltaic application of BFO has been hindered by low energy-conversion efficiency due to poor carrier transport and collection. In this work, a new approach of utilizing BFO as a light-absorbing sensitizer is developed to interface with charge-transporting TiO2 nanoparticles. This mesoporous all-oxide architecture, similar to that of dye-sensitized solar cells, can effectively facilitate the extraction of photocarriers. Under the standard AM1.5 (100 mW cm-2 ) irradiation, the optimized cell shows an open-circuit voltage of 0.67 V, which can be enhanced to 1.0 V by tailoring the bias history. A fill factor of 55% is achieved, which is much higher than those in previous reports on BFO-based photovoltaic devices. The results provide here a new viable approach toward developing highly tunable and stable photovoltaic devices based on ferroelectric transition-metal oxides.
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Affiliation(s)
- Lingfei Wang
- Materials Science and Engineering, King Abdullah University of Science and Technology (KAUST), Thuwal, 23955-6900, Kingdom of Saudi Arabia
| | - He Ma
- School of Materials Science and Engineering, Nanjing University of Science and Technology, Nanjing, 210094, P. R. China
| | - Lei Chang
- School of Materials Science and Engineering, Nanyang Technological University, Singapore, 639798
| | - Chun Ma
- Materials Science and Engineering, King Abdullah University of Science and Technology (KAUST), Thuwal, 23955-6900, Kingdom of Saudi Arabia
| | - Guoliang Yuan
- School of Materials Science and Engineering, Nanjing University of Science and Technology, Nanjing, 210094, P. R. China
| | - Junling Wang
- School of Materials Science and Engineering, Nanyang Technological University, Singapore, 639798
| | - Tom Wu
- Materials Science and Engineering, King Abdullah University of Science and Technology (KAUST), Thuwal, 23955-6900, Kingdom of Saudi Arabia
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120
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Seki A, Funatsu Y, Funahashi M. Anomalous photovoltaic effect based on molecular chirality: influence of enantiomeric purity on the photocurrent response in π-conjugated ferroelectric liquid crystals. Phys Chem Chem Phys 2017; 19:16446-16455. [DOI: 10.1039/c7cp02624b] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Photovoltaic effect based on molecular chirality was observed in π-conjugated ferroelectric liquid crystals.
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Affiliation(s)
- Atsushi Seki
- Department of Advanced Materials Science
- Faculty of Engineering
- Kagawa University
- Takamatsu
- Japan
| | - Yusuke Funatsu
- Department of Advanced Materials Science
- Faculty of Engineering
- Kagawa University
- Takamatsu
- Japan
| | - Masahiro Funahashi
- Department of Advanced Materials Science
- Faculty of Engineering
- Kagawa University
- Takamatsu
- Japan
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121
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Lee JH, Yoon C, Lee S, Kim YH, Park BH. Direct Observation of Domain Motion Synchronized with Resistive Switching in Multiferroic Thin Films. ACS APPLIED MATERIALS & INTERFACES 2016; 8:35464-35471. [PMID: 27977136 DOI: 10.1021/acsami.6b12756] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
The room-temperature resistive switching characteristics of ferroelectric, ferroelastic, and multiferroic materials are promising for application in nonvolatile memory devices. These resistive switching characteristics can be accompanied by a change in the ferroic order parameters via applied external electric and magnetic excitations. However, the dynamic evolution of the order parameters between two electrodes, which is synchronized with resistive switching, has rarely been investigated. In this study, for the first time, we directly monitor the ferroelectric/ferroelastic domain switching dynamics between two electrodes in multiferroic BiFeO3 (BFO) planar devices, which cause resistive switching, using piezoresponse force microscopy. It is demonstrated that the geometrical relationship between the ferroelectric domain and electrode in BFO planar capacitors with only 71° domain walls significantly affects both the ferroelectric domain dynamics and the resistive switching. The direct observation of domain dynamics relevant to resistive switching in planar devices may pave the way to a controllable combination of ferroelectric characteristics and resistive switching in multiferroic materials.
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Affiliation(s)
- Ji Hye Lee
- Division of Quantum Phase and Devices, Department of Physics, Konkuk University , Seoul 143-701, Korea
| | - Chansoo Yoon
- Division of Quantum Phase and Devices, Department of Physics, Konkuk University , Seoul 143-701, Korea
| | - Sangik Lee
- Division of Quantum Phase and Devices, Department of Physics, Konkuk University , Seoul 143-701, Korea
| | - Young Heon Kim
- Korea Research Institute of Standards and Science , Daejeon 305-304, Korea
| | - Bae Ho Park
- Division of Quantum Phase and Devices, Department of Physics, Konkuk University , Seoul 143-701, Korea
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122
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Ge C, Jin KJ, Zhang QH, Du JY, Gu L, Guo HZ, Yang JT, Gu JX, He M, Xing J, Wang C, Lu HB, Yang GZ. Toward Switchable Photovoltaic Effect via Tailoring Mobile Oxygen Vacancies in Perovskite Oxide Films. ACS APPLIED MATERIALS & INTERFACES 2016; 8:34590-34597. [PMID: 27936535 DOI: 10.1021/acsami.6b13203] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
The defect chemistry of perovskite oxides involves the cause to most of their abundant functional properties, including interface magnetism, charge transport, ionic exchange, and catalytic activity. The possibility to achieve dynamic control over oxygen anion vacancies offers a unique opportunity for the development of appealing switchable devices, which at present are commonly based on ferroelectric materials. Herein, we report the discovery of a switchable photovoltaic effect, that the sign of the open voltage and the short circuit current can be reversed by inverting the polarity of the applied field, upon electrically tailoring the distribution of oxygen vacancies in perovskite oxide films. This phenomenon is demonstrated in lateral photovoltaic devices based on both ferroelectric BiFeO3 and paraelectric SrTiO3 films, under a reversed applied field whose magnitude is much smaller than the coercivity value of BiFeO3. The migration of oxygen vacancies was directly observed by employing an advanced annular bright-field scanning transmission electron microscopy technique with in situ biasing equipment. We conclude that the band bending induced by the motion of oxygen vacancies is the driving force for the reversible switching between two photovoltaic states. The present work can provide an active path for the design of novel switchable photovoltaic devices with a wide range of transition metal oxides in terms of the ionic degrees of freedom.
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Affiliation(s)
- Chen Ge
- Institute of Physics, Chinese Academy of Sciences , Beijing 100190, China
| | - Kui-Juan Jin
- Institute of Physics, Chinese Academy of Sciences , Beijing 100190, China
- Collaborative Innovation Center of Quantum Matter , Beijing 100190, China
| | - Qing-Hua Zhang
- School of Materials Science and Engineering, State Key Lab of New Ceramics and Fine Processing, Tsinghua University , Beijing 100084, China
| | - Jian-Yu Du
- Institute of Physics, Chinese Academy of Sciences , Beijing 100190, China
- School of Science, China University of Geosciences , Beijing 100083, China
| | - Lin Gu
- Institute of Physics, Chinese Academy of Sciences , Beijing 100190, China
- Collaborative Innovation Center of Quantum Matter , Beijing 100190, China
| | - Hai-Zhong Guo
- Institute of Physics, Chinese Academy of Sciences , Beijing 100190, China
| | - Jing-Ting Yang
- Institute of Physics, Chinese Academy of Sciences , Beijing 100190, China
| | - Jun-Xing Gu
- Institute of Physics, Chinese Academy of Sciences , Beijing 100190, China
| | - Meng He
- Institute of Physics, Chinese Academy of Sciences , Beijing 100190, China
| | - Jie Xing
- School of Science, China University of Geosciences , Beijing 100083, China
| | - Can Wang
- Institute of Physics, Chinese Academy of Sciences , Beijing 100190, China
| | - Hui-Bin Lu
- Institute of Physics, Chinese Academy of Sciences , Beijing 100190, China
| | - Guo-Zhen Yang
- Institute of Physics, Chinese Academy of Sciences , Beijing 100190, China
- Collaborative Innovation Center of Quantum Matter , Beijing 100190, China
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123
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Pérez-Tomás A, Lira-Cantú M, Catalan G. Above-Bandgap Photovoltages in Antiferroelectrics. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2016; 28:9644-9647. [PMID: 27629252 DOI: 10.1002/adma.201603176] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2016] [Revised: 07/27/2016] [Indexed: 06/06/2023]
Abstract
The first antiferroelectric solar cell is presented. This study shows that antiferroelectric thin-film photovoltaic current can be switched on when biased into the polar phase to generate abovebandgap photovoltages in excess of 100 V and photovoltaic fields of several megavolts per centimeter, the largest ever measured for any material.
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Affiliation(s)
- Amador Pérez-Tomás
- Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and The Barcelona Institute of Science and Technology, Campus UAB, Bellaterra, 08193, Barcelona, Spain
| | - Monica Lira-Cantú
- Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and The Barcelona Institute of Science and Technology, Campus UAB, Bellaterra, 08193, Barcelona, Spain
| | - Gustau Catalan
- Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and The Barcelona Institute of Science and Technology, Campus UAB, Bellaterra, 08193, Barcelona, Spain
- Institut Català de Recerca i Estudis Avançats (ICREA), Barcelona, 08010, Catalonia, Spain
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124
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Liu J, Prashanthi K, Li Z, McGee RT, Ahadi K, Thundat T. Strain-induced electrostatic enhancements of BiFeO3 nanowire loops. Phys Chem Chem Phys 2016; 18:22772-7. [PMID: 27477993 DOI: 10.1039/c6cp03068h] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Semiconductor nanowires (NWs), due to their intriguing structural and physical properties, offer tremendous potential for future technological applications. The existence of strain in NWs can greatly affect, for instance, their mechanical, electrical and optical properties. Here, we report an extraordinary electrostatic response of semiconductor BiFeO3 NW loops, based on Kelvin probe force microscopy (KPFM) and electrostatic force microscopy (EFM). A substantial ∼300 mV surface potential difference, accompanied by an ∼29% higher surface charge density, was found on the NW loop. We also found that the electrostatic enhancement is strongly related to the strain present at the curvature of the NW loops. We propose that the electric polarization coupled with mechanical strain (piezoelectric effect) or strain gradient (flexoelectricity) as possible reasons to account for our observation. These findings provide new insights into multiferroic based semiconductor NWs under external stimuli as well as significant inspiration towards strain sensors and electromechanical devices with multifunctional sensing abilities.
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Affiliation(s)
- Jun Liu
- Department of Chemical and Materials Engineering, University of Alberta, Edmonton, Alberta T6G 2V4, Canada.
| | - Kovur Prashanthi
- Department of Chemical and Materials Engineering, University of Alberta, Edmonton, Alberta T6G 2V4, Canada.
| | - Zhi Li
- Department of Chemical and Materials Engineering, University of Alberta, Edmonton, Alberta T6G 2V4, Canada.
| | - Ryan T McGee
- Department of Chemical and Materials Engineering, University of Alberta, Edmonton, Alberta T6G 2V4, Canada.
| | - Kaveh Ahadi
- Department of Chemical and Materials Engineering, University of Alberta, Edmonton, Alberta T6G 2V4, Canada. and Materials Department, University of California, Santa Barbara, California 93106-5050, USA
| | - Thomas Thundat
- Department of Chemical and Materials Engineering, University of Alberta, Edmonton, Alberta T6G 2V4, Canada.
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125
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Damodaran AR, Agar JC, Pandya S, Chen Z, Dedon L, Xu R, Apgar B, Saremi S, Martin LW. New modalities of strain-control of ferroelectric thin films. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2016; 28:263001. [PMID: 27187744 DOI: 10.1088/0953-8984/28/26/263001] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Ferroelectrics, with their spontaneous switchable electric polarization and strong coupling between their electrical, mechanical, thermal, and optical responses, provide functionalities crucial for a diverse range of applications. Over the past decade, there has been significant progress in epitaxial strain engineering of oxide ferroelectric thin films to control and enhance the nature of ferroelectric order, alter ferroelectric susceptibilities, and to create new modes of response which can be harnessed for various applications. This review aims to cover some of the most important discoveries in strain engineering over the past decade and highlight some of the new and emerging approaches for strain control of ferroelectrics. We discuss how these new approaches to strain engineering provide promising routes to control and decouple ferroelectric susceptibilities and create new modes of response not possible in the confines of conventional strain engineering. To conclude, we will provide an overview and prospectus of these new and interesting modalities of strain engineering helping to accelerate their widespread development and implementation in future functional devices.
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Affiliation(s)
- Anoop R Damodaran
- Department of Materials Science and Engineering, University of California, Berkeley, Berkeley, California, USA
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126
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Paillard C, Bai X, Infante IC, Guennou M, Geneste G, Alexe M, Kreisel J, Dkhil B. Photovoltaics with Ferroelectrics: Current Status and Beyond. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2016; 28:5153-5168. [PMID: 27135419 DOI: 10.1002/adma.201505215] [Citation(s) in RCA: 117] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2015] [Revised: 01/31/2016] [Indexed: 06/05/2023]
Abstract
Ferroelectrics carry a switchable spontaneous electric polarization. This polarization is usually coupled to strain, making ferroelectrics good piezoelectrics. When coupled to magnetism, they become so-called multiferroic systems, a field that has been widely investigated since 2003. While ferroelectrics are birefringent and non-linear optically transparent materials, the coupling of polarization with optical properties has received, since 2009, renewed attention, triggered notably by low-bandgap ferroelectrics suitable for sunlight spectrum absorption and original photovoltaic effects. Consequently, power conversion efficiencies up to 8.1% were recently achieved and values of 19.5% were predicted, making photoferroelectrics promising photovoltaic alternatives. This article aims at providing an up-to-date review on this emerging and rapidly progressing field by highlighting several important issues and parameters, such as the role of domain walls, ways to tune the bandgap, consequences arising from the polarization switchability, and the role of defects and contact electrodes, as well as the downscaling effects. Beyond photovoltaicity, other polarization-related processes are also described, like light-induced deformation (photostriction) or light-assisted chemical reaction (photostriction). It is hoped that this overview will encourage further avenues to be explored and challenged and, as a byproduct, will inspire other research communities in material science, e.g., so-called hybrid halide perovskites.
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Affiliation(s)
- Charles Paillard
- Laboratoire Structures, Propriétés et Modélisation des Solides, CentraleSupélec, Université Paris-Saclay, CNRS-UMR 8580, 92295, Châtenay-Malabry Cedex, France
| | - Xiaofei Bai
- Laboratoire Structures, Propriétés et Modélisation des Solides, CentraleSupélec, Université Paris-Saclay, CNRS-UMR 8580, 92295, Châtenay-Malabry Cedex, France
| | - Ingrid C Infante
- Laboratoire Structures, Propriétés et Modélisation des Solides, CentraleSupélec, Université Paris-Saclay, CNRS-UMR 8580, 92295, Châtenay-Malabry Cedex, France
- Materials Research and Technology Department, Luxembourg Institute of Science and Technology, 41 rue du Brill, L-4422, Belvaux, Luxembourg
| | - Maël Guennou
- Materials Research and Technology Department, Luxembourg Institute of Science and Technology, 41 rue du Brill, L-4422, Belvaux, Luxembourg
| | | | - Marin Alexe
- Department of Physics, University of Warwick, Coventry, CV, 47AL, UK
| | - Jens Kreisel
- Materials Research and Technology Department, Luxembourg Institute of Science and Technology, 41 rue du Brill, L-4422, Belvaux, Luxembourg
- Physics and Materials Science Research Unit, University of Luxembourg, 41 Rue du Brill, L-4422, Belvaux, Luxembourg
| | - Brahim Dkhil
- Laboratoire Structures, Propriétés et Modélisation des Solides, CentraleSupélec, Université Paris-Saclay, CNRS-UMR 8580, 92295, Châtenay-Malabry Cedex, France
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127
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Tan LZ, Rappe AM. Enhancement of the Bulk Photovoltaic Effect in Topological Insulators. PHYSICAL REVIEW LETTERS 2016; 116:237402. [PMID: 27341257 DOI: 10.1103/physrevlett.116.237402] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/14/2015] [Indexed: 06/06/2023]
Abstract
We investigate the shift current bulk photovoltaic response of materials close to a band inversion topological phase transition. We find that the bulk photocurrent reverses direction across the band inversion transition, and that its magnitude is enhanced in the vicinity of the phase transition. These results are demonstrated with first principles density functional theory calculations of BiTeI and CsPbI_{3} under hydrostatic pressure, and explained with an analytical model, suggesting that this phenomenon remains robust across disparate material systems.
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Affiliation(s)
- Liang Z Tan
- The Makineni Theoretical Laboratories, Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6323, USA
| | - Andrew M Rappe
- The Makineni Theoretical Laboratories, Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6323, USA
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128
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Seki A, Funahashi M. Photovoltaic Effects in Ferroelectric Liquid Crystals based on Phenylterthiophene Derivatives. CHEM LETT 2016. [DOI: 10.1246/cl.160183] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Affiliation(s)
- Atsushi Seki
- Department of Advanced Materials Science, Faculty of Engineering, Kagawa University
| | - Masahiro Funahashi
- Department of Advanced Materials Science, Faculty of Engineering, Kagawa University
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129
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Morimoto T, Nagaosa N. Topological nature of nonlinear optical effects in solids. SCIENCE ADVANCES 2016; 2:e1501524. [PMID: 27386523 PMCID: PMC4928882 DOI: 10.1126/sciadv.1501524] [Citation(s) in RCA: 97] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2015] [Accepted: 04/20/2016] [Indexed: 05/05/2023]
Abstract
There are a variety of nonlinear optical effects including higher harmonic generations, photovoltaic effects, and nonlinear Kerr rotations. They are realized by strong light irradiation to materials that results in nonlinear polarizations in the electric field. These are of great importance in studying the physics of excited states of the system as well as for applications to optical devices and solar cells. Nonlinear properties of materials are usually described by nonlinear susceptibilities, which have complex expressions including many matrix elements and energy denominators. On the other hand, a nonequilibrium steady state under an electric field periodic in time has a concise description in terms of the Floquet bands of electrons dressed by photons. We show theoretically, using the Floquet formalism, that various nonlinear optical effects, such as the shift current in noncentrosymmetric materials, photovoltaic Hall response, and photo-induced change of order parameters under the continuous irradiation of monochromatic light, can be described in a unified fashion by topological quantities involving the Berry connection and Berry curvature. We found that vector fields defined with the Berry connections in the space of momentum and/or parameters govern the nonlinear responses. This topological view offers a route to designing nonlinear optical materials.
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Affiliation(s)
- Takahiro Morimoto
- Department of Physics, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Naoto Nagaosa
- RIKEN Center for Emergent Matter Science (CEMS), Wako, Saitama 351-0198, Japan
- Department of Applied Physics, University of Tokyo, Tokyo 113-8656, Japan
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130
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Liu F, Fina I, Bertacco R, Fontcuberta J. Unravelling and controlling hidden imprint fields in ferroelectric capacitors. Sci Rep 2016; 6:25028. [PMID: 27122309 PMCID: PMC4848548 DOI: 10.1038/srep25028] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2015] [Accepted: 04/01/2016] [Indexed: 11/11/2022] Open
Abstract
Ferroelectric materials have a spontaneous polarization that can point along energetically equivalent, opposite directions. However, when ferroelectric layers are sandwiched between different metallic electrodes, asymmetric electrostatic boundary conditions may induce the appearance of an electric field (imprint field, Eimp) that breaks the degeneracy of the polarization directions, favouring one of them. This has dramatic consequences on functionality of ferroelectric-based devices such as ferroelectric memories or photodetectors. Therefore, to cancel out the Eimp, ferroelectric components are commonly built using symmetric contact configuration. Indeed, in this symmetric contact configuration, when measurements are done under time-varying electric fields of relatively low frequency, an archetypical symmetric single-step switching process is observed, indicating Eimp ≈ 0. However, we report here on the discovery that when measurements are performed at high frequency, a well-defined double-step switching is observed, indicating the presence of Eimp. We argue that this frequency dependence originates from short-living head-to-head or tail-to-tail ferroelectric capacitors in the device. We demonstrate that we can modulate Eimp and the life-time of head-to-head or tail-to-tail polarization configurations by adjusting the polarization screening charges by suitable illumination. These findings are of relevance to understand the effects of internal electric fields on pivotal ferroelectric properties, such as memory retention and photoresponse.
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Affiliation(s)
- Fanmao Liu
- Institut de Ciència de Materials de Barcelona (ICMAB-CSIC), Campus UAB, Bellaterra 08193, Catalonia, Spain
| | - Ignasi Fina
- Institut Català de Nanociència i Nanotecnologia and The Barcelona Institute of Science and Technology (ICN2-BIST), Campus UAB, Bellaterra 08193, Catalonia, Spain
| | - Riccardo Bertacco
- LNESS Center - Dipartimento di Fisica del Politecnico di Milano, Como 22100, Italy
| | - Josep Fontcuberta
- Institut de Ciència de Materials de Barcelona (ICMAB-CSIC), Campus UAB, Bellaterra 08193, Catalonia, Spain
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131
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Pan DF, Bi GF, Chen GY, Zhang H, Liu JM, Wang GH, Wan JG. Polarization-dependent interfacial coupling modulation of ferroelectric photovoltaic effect in PZT-ZnO heterostructures. Sci Rep 2016; 6:22948. [PMID: 26954833 PMCID: PMC4782167 DOI: 10.1038/srep22948] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2015] [Accepted: 02/24/2016] [Indexed: 11/09/2022] Open
Abstract
Recently, ferroelectric perovskite oxides have drawn much attention due to potential applications in the field of solar energy conversion. However, the power conversion efficiency of ferroelectric photovoltaic effect currently reported is far below the expectable value. One of the crucial problems lies in the two back-to-back Schottky barriers, which are formed at the ferroelectric-electrode interfaces and blocking most of photo-generated carriers to reach the outside circuit. Herein, we develop a new approach to enhance the ferroelectric photovoltaic effect by introducing the polarization-dependent interfacial coupling effect. Through inserting a semiconductor ZnO layer with spontaneous polarization into the ferroelectric ITO/PZT/Au film, a p-n junction with strong polarization-dependent interfacial coupling effect is formed. The power conversion efficiency of the heterostructure is improved by nearly two orders of magnitude and the polarization modulation ratio is increased about four times. It is demonstrated that the polarization-dependent interfacial coupling effect can give rise to a great change in band structure of the heterostructure, not only producing an aligned internal electric field but also tuning both depletion layer width and potential barrier height at PZT-ZnO interface. This work provides an efficient way in developing highly efficient ferroelectric-based solar cells and novel optoelectronic memory devices.
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Affiliation(s)
- Dan-Feng Pan
- National Laboratory of Solid State Microstructures and Department of Physics, Nanjing University, Nanjing 210093, China
| | - Gui-Feng Bi
- National Laboratory of Solid State Microstructures and Department of Physics, Nanjing University, Nanjing 210093, China
| | - Guang-Yi Chen
- National Laboratory of Solid State Microstructures and Department of Physics, Nanjing University, Nanjing 210093, China
| | - Hao Zhang
- Department of Physics and Astronomy, University of Kentucky, Lexington, Kentucky 40506-0055, USA
| | - Jun-Ming Liu
- National Laboratory of Solid State Microstructures and Department of Physics, Nanjing University, Nanjing 210093, China.,Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
| | - Guang-Hou Wang
- National Laboratory of Solid State Microstructures and Department of Physics, Nanjing University, Nanjing 210093, China.,Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
| | - Jian-Guo Wan
- National Laboratory of Solid State Microstructures and Department of Physics, Nanjing University, Nanjing 210093, China.,Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
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132
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Substantial bulk photovoltaic effect enhancement via nanolayering. Nat Commun 2016; 7:10419. [PMID: 26791545 PMCID: PMC4735945 DOI: 10.1038/ncomms10419] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2015] [Accepted: 12/10/2015] [Indexed: 11/09/2022] Open
Abstract
Spontaneous polarization and inversion symmetry breaking in ferroelectric materials lead to their use as photovoltaic devices. However, further advancement of their applications are hindered by the paucity of ways of reducing bandgaps and enhancing photocurrent. By unravelling the correlation between ferroelectric materials' responses to solar irradiation and their local structure and electric polarization landscapes, here we show from first principles that substantial bulk photovoltaic effect enhancement can be achieved by nanolayering PbTiO3 with nickel ions and oxygen vacancies ((PbNiO2)x(PbTiO3)(1-x)). The enhancement of the total photocurrent for different spacings between the Ni-containing layers can be as high as 43 times due to a smaller bandgap and photocurrent direction alignment for all absorption energies. This is due to the electrostatic effect that arises from nanolayering. This opens up the possibility for control of the bulk photovoltaic effect in ferroelectric materials by nanoscale engineering of their structure and composition.
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133
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Giant optical enhancement of strain gradient in ferroelectric BiFeO3 thin films and its physical origin. Sci Rep 2015; 5:16650. [PMID: 26586421 PMCID: PMC4653733 DOI: 10.1038/srep16650] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2015] [Accepted: 10/16/2015] [Indexed: 11/18/2022] Open
Abstract
Through mapping of the spatiotemporal strain profile in ferroelectric BiFeO3 epitaxial thin films, we report an optically initiated dynamic enhancement of the strain gradient of 105–106 m−1 that lasts up to a few ns depending on the film thickness. Correlating with transient optical absorption measurements, the enhancement of the strain gradient is attributed to a piezoelectric effect driven by a transient screening field mediated by excitons. These findings not only demonstrate a new possible way of controlling the flexoelectric effect, but also reveal the important role of exciton dynamics in photostriction and photovoltaic effects in ferroelectrics.
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134
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Inoue R, Ishikawa S, Imura R, Kitanaka Y, Oguchi T, Noguchi Y, Miyayama M. Giant photovoltaic effect of ferroelectric domain walls in perovskite single crystals. Sci Rep 2015; 5:14741. [PMID: 26443381 PMCID: PMC4595799 DOI: 10.1038/srep14741] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2015] [Accepted: 09/02/2015] [Indexed: 11/09/2022] Open
Abstract
The photovoltaic (PV) effect in polar materials offers great potential for light-energy conversion that generates a voltage beyond the bandgap limit of present semiconductor-based solar cells. Ferroelectrics have received renewed attention because of the ability to deliver a high voltage in the presence of ferroelastic domain walls (DWs). In recent years, there has been considerable debate over the impact of the DWs on the PV effects, owing to lack of information on the bulk PV tensor of host ferroelectrics. In this article, we provide the first direct evidence of an unusually large PV response induced by ferroelastic DWs-termed 'DW'-PV effect. The precise estimation of the bulk PV tensor in single crystals of barium titanate enables us to quantify the giant PV effect driven by 90° DWs. We show that the DW-PV effect arises from an effective electric field consisting of a potential step and a local PV component in the 90° DW region. This work offers a starting point for further investigation into the DW-PV effect of alternative systems and opens a reliable route for enhancing the PV properties in ferroelectrics based on the engineering of domain structures in either bulk or thin-film form.
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Affiliation(s)
- Ryotaro Inoue
- Dept. of Applied Chemistry, School of Engineering, The University of Tokyo, Bunkyo-ku, Tokyo 113-8654, Japan
| | - Shotaro Ishikawa
- Dept. of Applied Chemistry, School of Engineering, The University of Tokyo, Bunkyo-ku, Tokyo 113-8654, Japan
| | - Ryota Imura
- Dept. of Applied Chemistry, School of Engineering, The University of Tokyo, Bunkyo-ku, Tokyo 113-8654, Japan
| | - Yuuki Kitanaka
- Dept. of Applied Chemistry, School of Engineering, The University of Tokyo, Bunkyo-ku, Tokyo 113-8654, Japan
| | - Takeshi Oguchi
- Dept. of Applied Chemistry, School of Engineering, The University of Tokyo, Bunkyo-ku, Tokyo 113-8654, Japan
| | - Yuji Noguchi
- Dept. of Applied Chemistry, School of Engineering, The University of Tokyo, Bunkyo-ku, Tokyo 113-8654, Japan
| | - Masaru Miyayama
- Dept. of Applied Chemistry, School of Engineering, The University of Tokyo, Bunkyo-ku, Tokyo 113-8654, Japan
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135
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Leguy AMA, Frost JM, McMahon AP, Sakai VG, Kochelmann W, Law C, Li X, Foglia F, Walsh A, O'Regan BC, Nelson J, Cabral JT, Barnes PRF. The dynamics of methylammonium ions in hybrid organic-inorganic perovskite solar cells. Nat Commun 2015; 6:7124. [PMID: 26023041 PMCID: PMC4458867 DOI: 10.1038/ncomms8124] [Citation(s) in RCA: 229] [Impact Index Per Article: 25.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2014] [Accepted: 04/07/2015] [Indexed: 12/23/2022] Open
Abstract
Methylammonium lead iodide perovskite can make high-efficiency solar cells, which also show an unexplained photocurrent hysteresis dependent on the device-poling history. Here we report quasielastic neutron scattering measurements showing that dipolar CH3NH3+ ions reorientate between the faces, corners or edges of the pseudo-cubic lattice cages in CH3NH3PbI3 crystals with a room temperature residence time of ∼14 ps. Free rotation, π-flips and ionic diffusion are ruled out within a 1–200-ps time window. Monte Carlo simulations of interacting CH3NH3+ dipoles realigning within a 3D lattice suggest that the scattering measurements may be explained by the stabilization of CH3NH3+ in either antiferroelectric or ferroelectric domains. Collective realignment of CH3NH3+ to screen a device's built-in potential could reduce photovoltaic performance. However, we estimate the timescale for a domain wall to traverse a typical device to be ∼0.1–1 ms, faster than most observed hysteresis. Hysteresis often exists in the characterization of methylammonium lead halide-based solar cells, but is not well understood. Here, the authors use quasielastic neutron scattering to study the dynamics of dipolar organic cations and shed light on the hysteresis behaviour.
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Affiliation(s)
| | - Jarvist Moore Frost
- Department of Chemistry, University of Bath, Claverton Down, Bath BA2 7AY, UK
| | - Andrew P McMahon
- Department of Physics, Imperial College London, London SW7 2AZ, UK
| | | | - W Kochelmann
- Rutherford Appleton Laboratory, Harwell, Didcot OX11 0QX, UK
| | - ChunHung Law
- Department of Chemistry, Imperial College London, London SW7 2AZ, UK
| | - Xiaoe Li
- Department of Chemistry, Imperial College London, London SW7 2AZ, UK
| | - Fabrizia Foglia
- Department of Chemical Engineering, Imperial College London, London SW7 2AZ, UK
| | - Aron Walsh
- Department of Chemistry, University of Bath, Claverton Down, Bath BA2 7AY, UK
| | - Brian C O'Regan
- Department of Chemistry, Imperial College London, London SW7 2AZ, UK
| | - Jenny Nelson
- Department of Physics, Imperial College London, London SW7 2AZ, UK
| | - João T Cabral
- Department of Chemical Engineering, Imperial College London, London SW7 2AZ, UK
| | - Piers R F Barnes
- Department of Physics, Imperial College London, London SW7 2AZ, UK
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136
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Zhao L, Lu Z, Zhang F, Tian G, Song X, Li Z, Huang K, Zhang Z, Qin M, SujuanWu, Lu X, Zeng M, Gao X, Dai J, Liu JM. Current rectifying and resistive switching in high density BiFeO3 nanocapacitor arrays on Nb-SrTiO3 substrates. Sci Rep 2015; 5:9680. [PMID: 25853937 PMCID: PMC4389717 DOI: 10.1038/srep09680] [Citation(s) in RCA: 57] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2014] [Accepted: 03/16/2015] [Indexed: 11/17/2022] Open
Abstract
Ultrahigh density well-registered oxide nanocapacitors are very essential for large scale integrated microelectronic devices. We report the fabrication of well-ordered multiferroic BiFeO3 nanocapacitor arrays by a combination of pulsed laser deposition (PLD) method and anodic aluminum oxide (AAO) template method. The capacitor cells consist of BiFeO3/SrRuO3 (BFO/SRO) heterostructural nanodots on conductive Nb-doped SrTiO3 (Nb-STO) substrates with a lateral size of ~60 nm. These capacitors also show reversible polarization domain structures, and well-established piezoresponse hysteresis loops. Moreover, apparent current-rectification and resistive switching behaviors were identified in these nanocapacitor cells using conductive-AFM technique, which are attributed to the polarization modulated p-n junctions. These make it possible to utilize these nanocapacitors in high-density (>100 Gbit/inch(2)) nonvolatile memories and other oxide nanoelectronic devices.
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Affiliation(s)
- Lina Zhao
- Institute for Advanced Materials and Guangdong Provincial Key Laboratory of Quantum Engineering and Quantum Materials, South China Normal University, Guangzhou 510006, China
| | - Zengxing Lu
- Institute for Advanced Materials and Guangdong Provincial Key Laboratory of Quantum Engineering and Quantum Materials, South China Normal University, Guangzhou 510006, China
| | - Fengyuan Zhang
- Institute for Advanced Materials and Guangdong Provincial Key Laboratory of Quantum Engineering and Quantum Materials, South China Normal University, Guangzhou 510006, China
| | - Guo Tian
- Institute for Advanced Materials and Guangdong Provincial Key Laboratory of Quantum Engineering and Quantum Materials, South China Normal University, Guangzhou 510006, China
| | - Xiao Song
- Institute for Advanced Materials and Guangdong Provincial Key Laboratory of Quantum Engineering and Quantum Materials, South China Normal University, Guangzhou 510006, China
| | - Zhongwen Li
- Institute for Advanced Materials and Guangdong Provincial Key Laboratory of Quantum Engineering and Quantum Materials, South China Normal University, Guangzhou 510006, China
| | - Kangrong Huang
- Institute for Advanced Materials and Guangdong Provincial Key Laboratory of Quantum Engineering and Quantum Materials, South China Normal University, Guangzhou 510006, China
| | - Zhang Zhang
- Institute for Advanced Materials and Guangdong Provincial Key Laboratory of Quantum Engineering and Quantum Materials, South China Normal University, Guangzhou 510006, China
| | - Minghui Qin
- Institute for Advanced Materials and Guangdong Provincial Key Laboratory of Quantum Engineering and Quantum Materials, South China Normal University, Guangzhou 510006, China
| | - SujuanWu
- Institute for Advanced Materials and Guangdong Provincial Key Laboratory of Quantum Engineering and Quantum Materials, South China Normal University, Guangzhou 510006, China
| | - Xubing Lu
- Institute for Advanced Materials and Guangdong Provincial Key Laboratory of Quantum Engineering and Quantum Materials, South China Normal University, Guangzhou 510006, China
| | - Min Zeng
- Institute for Advanced Materials and Guangdong Provincial Key Laboratory of Quantum Engineering and Quantum Materials, South China Normal University, Guangzhou 510006, China
| | - Xingsen Gao
- Institute for Advanced Materials and Guangdong Provincial Key Laboratory of Quantum Engineering and Quantum Materials, South China Normal University, Guangzhou 510006, China
| | - Jiyan Dai
- Department of Applied Physics, The Hong Kong Polytechnic University, Hong Kong, China
| | - Jun-Ming Liu
- Laboratory of Solid State Microstructures and Innovation Center of Advanced Microstructures, Nanjing University, 210093, China
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137
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Fei L, Hu Y, Li X, Song R, Sun L, Huang H, Gu H, Chan HLW, Wang Y. Electrospun bismuth ferrite nanofibers for potential applications in ferroelectric photovoltaic devices. ACS APPLIED MATERIALS & INTERFACES 2015; 7:3665-3670. [PMID: 25622097 DOI: 10.1021/acsami.5b00069] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Bismuth ferrite (BFO) nanofibers were synthesized via a sol-gel-based electrospinning process followed by thermal treatment. The influences of processing conditions on the final structure of the samples were investigated. Nanofibers prepared under optimized conditions were found to have a perovskite structure with good quality of crystallization and free of impurity phase. Ferroelectric and piezoelectric responses were obtained from individual nanofiber measured on a piezoelectric force microscope. A prototype photovoltaic device using laterally aligned BFO nanofibers and interdigital electrodes was developed and its performance was examined on a standard photovoltaic system. The BFO nanofibers were found to exhibit an excellent ferroelectric photovoltaic property with the photocurrent several times larger than the literature data obtained on BFO thin films.
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Affiliation(s)
- Linfeng Fei
- Department of Applied Physics and Materials Research Center, The Hong Kong Polytechnic University , Hong Kong SAR, China
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138
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Doig KI, Peters JJP, Nawaz S, Walker D, Walker M, Lees MR, Beanland R, Sanchez AM, McConville CF, Palkar VR, Lloyd-Hughes J. Structural, optical and vibrational properties of self-assembled Pbn+1(Ti1-x Fex)nO(3n+1)-δ Ruddlesden-Popper superstructures. Sci Rep 2015; 5:7719. [PMID: 25591924 PMCID: PMC4296293 DOI: 10.1038/srep07719] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2014] [Accepted: 12/09/2014] [Indexed: 02/08/2023] Open
Abstract
Bulk crystals and thin films of PbTi1−xFexO3−δ (PTFO) are multiferroic, exhibiting ferroelectricity and ferromagnetism at room temperature. Here we report that the Ruddlesden-Popper phase Pbn+1(Ti1−xFex)nO3n+1−δ forms spontaneously during pulsed laser deposition of PTFO on LaAlO3 substrates. High-resolution transmission electron microscopy, x-ray diffraction and x-ray photoemission spectroscopy were utilised to perform a structural and compositional analysis, demonstrating that and . The complex dielectric function of the films was determined from far-infrared to ultraviolet energies using a combination of terahertz time-domain spectroscopy, Fourier transform spectroscopy, and spectroscopic ellipsometry. The simultaneous Raman and infrared activity of phonon modes and the observation of second harmonic generation establishes a non-centrosymmetric point group for Pbn+1(Ti0.5Fe0.5)nO3n+1−δ, a prerequisite for (but not proof of) ferroelectricity. No evidence of macroscopic ferromagnetism was found in SQUID magnetometry. The ultrafast optical response exhibited coherent magnon oscillations compatible with local magnetic order, and additionally was used to study photocarrier cooling on picosecond timescales. An optical gap smaller than that of BiFeO3 and long photocarrier lifetimes may make this system interesting as a ferroelectric photovoltaic.
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Affiliation(s)
- K I Doig
- University of Oxford, Department of Physics, Clarendon Laboratory, Parks Road, Oxford, OX1 3PU, United Kingdom
| | - J J P Peters
- University of Warwick, Department of Physics, Gibbet Hill Road, Coventry, CV4 7AL, United Kingdom
| | - S Nawaz
- Indian Institute of Technology Bombay, Mumbai 400076, India
| | - D Walker
- University of Warwick, Department of Physics, Gibbet Hill Road, Coventry, CV4 7AL, United Kingdom
| | - M Walker
- University of Warwick, Department of Physics, Gibbet Hill Road, Coventry, CV4 7AL, United Kingdom
| | - M R Lees
- University of Warwick, Department of Physics, Gibbet Hill Road, Coventry, CV4 7AL, United Kingdom
| | - R Beanland
- University of Warwick, Department of Physics, Gibbet Hill Road, Coventry, CV4 7AL, United Kingdom
| | - A M Sanchez
- University of Warwick, Department of Physics, Gibbet Hill Road, Coventry, CV4 7AL, United Kingdom
| | - C F McConville
- University of Warwick, Department of Physics, Gibbet Hill Road, Coventry, CV4 7AL, United Kingdom
| | - V R Palkar
- Indian Institute of Technology Bombay, Mumbai 400076, India
| | - J Lloyd-Hughes
- University of Warwick, Department of Physics, Gibbet Hill Road, Coventry, CV4 7AL, United Kingdom
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139
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Sando D, Barthélémy A, Bibes M. BiFeO3 epitaxial thin films and devices: past, present and future. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2014; 26:473201. [PMID: 25352066 DOI: 10.1088/0953-8984/26/47/473201] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The celebrated renaissance of the multiferroics family over the past ten years has also been that of its most paradigmatic member, bismuth ferrite (BiFeO3). Known since the 1960s to be a high temperature antiferromagnet and since the 1970s to be ferroelectric, BiFeO3 only had its bulk ferroic properties clarified in the mid-2000s. It is however the fabrication of BiFeO3 thin films and their integration into epitaxial oxide heterostructures that have fully revealed its extraordinarily broad palette of functionalities. Here we review the first decade of research on BiFeO3 films, restricting ourselves to epitaxial structures. We discuss how thickness and epitaxial strain influence not only the unit cell parameters, but also the crystal structure, illustrated for instance by the discovery of the so-called T-like phase of BiFeO3. We then present its ferroelectric and piezoelectric properties and their evolution near morphotropic phase boundaries. Magnetic properties and their modification by thickness and strain effects, as well as optical parameters, are covered. Finally, we highlight various types of devices based on BiFeO3 in electronics, spintronics, and optics, and provide perspectives for the development of further multifunctional devices for information technology and energy harvesting.
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Affiliation(s)
- D Sando
- Unité Mixte de Physique CNRS/Thales, 1 Avenue Fresnel, Campus de l'Ecole Polytechnique, 91767 Palaiseau, France, and Université Paris Sud, 91405 Orsay, France. Center for Correlated Electron Systems, Institute for Basic Science (IBS), and Department of Physics and Astronomy, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 151-747, Republic of Korea
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Brehm JA, Young SM, Zheng F, Rappe AM. First-principles calculation of the bulk photovoltaic effect in the polar compounds LiAsS2, LiAsSe2, and NaAsSe2. J Chem Phys 2014; 141:204704. [DOI: 10.1063/1.4901433] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- John A. Brehm
- The Makineni Theoretical Laboratories, Department of Chemistry, University of Pennsylvania, 231 S. 34th Street, Philadelphia, Pennsylvania 19104-6323, USA
| | - Steve M. Young
- The Makineni Theoretical Laboratories, Department of Chemistry, University of Pennsylvania, 231 S. 34th Street, Philadelphia, Pennsylvania 19104-6323, USA
| | - Fan Zheng
- The Makineni Theoretical Laboratories, Department of Chemistry, University of Pennsylvania, 231 S. 34th Street, Philadelphia, Pennsylvania 19104-6323, USA
| | - Andrew M. Rappe
- The Makineni Theoretical Laboratories, Department of Chemistry, University of Pennsylvania, 231 S. 34th Street, Philadelphia, Pennsylvania 19104-6323, USA
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Cao D, Wang Z, Nasori, Wen L, Mi Y, Lei Y. Switchable Charge-Transfer in the Photoelectrochemical Energy-Conversion Process of Ferroelectric BiFeO3Photoelectrodes. Angew Chem Int Ed Engl 2014; 53:11027-31. [DOI: 10.1002/anie.201406044] [Citation(s) in RCA: 87] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2014] [Indexed: 11/09/2022]
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Cao D, Wang Z, Nasori, Wen L, Mi Y, Lei Y. Switchable Charge-Transfer in the Photoelectrochemical Energy-Conversion Process of Ferroelectric BiFeO3Photoelectrodes. Angew Chem Int Ed Engl 2014. [DOI: 10.1002/ange.201406044] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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