Inorganic Chemistry Frontiers
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2022
·Vol. 10
·期 4
·1215-1224
·
IF 7.779
Jiaqi Ding,Hangren Li,Guoqiang Xi,Jie Tu,Jianjun Tian,Linxing Zhang
The wide band gap of bismuth ferrate-based materials limits their application in optoelectronic devices, and how to achieve band gap modulation in the simplest manner is the primary requirement for their industrialization. BiFeO3 (BFO) films can achieve narrower bandgaps than those under substrate strain, interphase strain, or chemical strain. In this study, we have achieved simultaneously increased tetragonality and reduced bandgaps in the tetragonal-like phase BFO-based films through chemical strain. Co substitution can be controlled by both stoichiometric ratios and atomic deposition rates. The tetragonality can increase up to a large c/a of 1.239, and the bandgap can decrease to 1.45 eV from 2.21 eV. The oxygen vacancies are closely related to the decrease of the band gap. Density functional theory calculations indicate that the introduction of Co and oxygen vacancies essentially reduced the conduction band bottom, resulting from the hybridization energy levels of Co 3d and O 2p, respectively. This paper provides a new strategy for the regulation of the optical band gap of BFO and further reveals its underlying mechanism.
研究领域:
材料科学
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物理学
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光学工程
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产品关联
DOI
高影响因子
International Journal of Minerals Metallurgy and Materials
·
2024
·Vol. 31
·期 10
·2263-2273
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IF 5.6
Lu Dongfei,Xi Guoqiang,Li Hangren,Tu Jie,Liu Xiuqiao,Liu Xudong,Tian Jianjun,Zhang Linxing
BiFeO 3 (BFO) has received considerable attention as a lead-free ferroelectric film due to its large theoretical remnant polarization. However, BFO suffers from a large leakage current, resulting in poor ferroelectric properties. Herein, the sol–gel method was used to deposit a series of BFO-based thin films on fluorine-doped tin oxide substrates, and the effects of the substitution of the elements Co, Cu, Mn ( B -site) and Sm, Eu, La ( A -site) on the crystal structure, ferroelectricity, and leakage current of the BFO-based thin films were investigated. Results confirmed that lattice distortion by X-ray diffraction can be attributed to the substitution of individual elements in the BFO-based films. Sm and Eu substitutions contribute to the lattice distortion in a pseudo-cubic structure, while La is biased toward pseudo-tetragonal. Piezoelectric force microscopy confirmed that reversible switching of ferroelectric domains by nearly 180° can be realized through the prepared films. The ferroelectric hysteresis loops showed that the order for the polarization contribution is as follows: Cu > Co > Mn ( B -site), Sm > La > Eu ( A -site). The current density voltage curves indicated that the order for leakage contribution is as follows: Mn < Cu < Co ( B -site), La < Eu < Sm ( A -site). Scanning electron microscopy showed that the introduction of Cu elements facilitates the formation of dense grains, and the grain size distribution statistics proved that La element promotes the reduction of grain size, leading to the increase of grain boundaries and the reduction of leakage. Finally, a Bi 0.985 Sm 0.045 La 0.03 Fe 0.96 Co 0.02 Cu 0.02 O 3 (SmLa-CoCu) thin film with a qualitative leap in the remnant polarization from 25.5 (Bi 0.985 Sm 0.075 FeO 3 ) to 98.8 µC/cm 2 (SmLa-CoCu) was prepared through the synergistic action of Sm, La, Co, and Cu elements. The leakage current is also drastically reduced from 160 to 8.4 mA/cm 2 at a field strength of 150 kV/cm. Thus, based on the increasing entropy strategy of chemical engineering, this study focuses on enhancing ferroelectricity and decreasing leakage current, providing a promising path for the advancement of ferroelectric devices.
研究领域:
材料科学
·
物理学
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DOI
高影响因子
Journal of Materials Chemistry C
·
2015
·Vol. 3
·期 18
·4706-4712
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IF 4.696
Linxing Zhang,Jun Chen,Jiangli Cao,Dongyu He,Xianran Xing
The destructive readout signal distinguishing the ferroelectric polarization state in a memory device has long been seen as the bottleneck for its commercial application. Both ferroelectric resistive switching and the switchable photovoltaic effect provide multiple choices for non-destructive readout. The polycrystalline ferroelectric BiFeO3-based thin films fabricated by cost-effective chemical solution growth exhibit large resistive switching (with ON/OFF ratios ∼104), which is comparable to switchable diodes and tunnel junctions. Furthermore, switchable photovoltaic response shows stable switching and good retention properties. The standard hysteretic loops of resistive switching current, short circuit current and open circuit voltage versus poling voltage directly indicate hysteretic modulation by ferroelectric polarization, which is the first evidence in polycrystalline BiFeO3 based films. The present films would be potential candidates for non-destructive ferroelectric memory devices with multiple selections.
研究领域:
材料科学
·
电子工程
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DOI
高影响因子
Advanced Materials Interfaces
·
2017
·Vol. 5
·期 3
·1701189
·
IF 4.279
Jia Qi,Nan Ma,Ya Yang
Ferroelectric material BiFeO 3 with narrow bandgap of 2.67 eV can be more suitable to fabricate photodetectors instead of solar energy harvesters because of low energy conversion efficiency. Herein, a BiFeO 3 film-based self-powered photodetector is reported by using the photovoltaic–pyroelectric coupled effect to enable a fast sensing of 450 nm light illumination. Compared with photovoltaic effect, the photosensitivity parameters including photoconductive gain, responsivity, and specific detectivity can be enhanced by more than 9.7 times at light intensity of 0.86 mW cm −2 by utilizing light-induced photovoltaic–pyroelectric coupled effect. Moreover, a self-powered photodetector array system is achieved to detect 450 nm light by analyzing the real-time recorded output voltage signals as a mapping figure. In this work a new route to realize the performance enhancement of photodetector via photovoltaic–pyroelectric coupled effect on ferroelectric materials, which has great significance in extending the field of self-powered photodetectors is described.
研究领域:
材料科学
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光电探测技术
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产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2025
·
IF 6.3
Shuzhi Zhang,Panpan Lv,Yuxin Cui,Tong Pan,Wentao Yang,Hang Zhan,Jia Wang,Ruihang Li,Cuncheng Li,Luchao Ren,Mingwei Zhang
Lead-free dielectric capacitors have been garnering increasing attention for pulsed power applications owing to their green sustainability. BiFeO 3 (BFO) is widely researched in association with dielectric energy-storage applications, owing to its large saturated polarization and high Curie temperature. However, it suffers from serious leakage problems. In this work, BFO-based thin films with different stacking structures are designed and fabricated by introducing a linear dielectric material, SrTiO 3 (STO). The experimental results and finite-element simulations indicate that the polarization and breakdown strength can be simultaneously optimized by regulating the position of the STO layer. In particular, a recoverable energy density of 70 J/cm 3 and efficiency of 60 % is achieved in sandwiched Bi(Fe 0.93 Mn 0.05 Ti 0.02 )O 3 /SrTiO 3 /Bi(Fe 0.93 Mn 0.05 Ti 0.02 )O 3 (BFMTO/STO/BFMTO) film, owing to the synergistic effect of different dielectrics as well as the blocking effect of the interface. The capacitor exhibits a wide operating temperature window (-100–125 °C) and high frequency stability (1–20 kHz), as well as strong fatigue durability (2 × 10 7 cycles). These results demonstrate that the BFMTO/STO/BFMTO film is a promising ecofriendly material for advanced power-capacitor applications.
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DOI
高影响因子
Nano-Micro Letters
·
2022
·Vol. 14
·期 1
·1-14
·
IF 23.655
Han Xiao,Ji Yun,Wu Li,Xia Yanlong,Bowen Chris R.,Yang Ya
Coupled nanogenerators have been a research hotspot due to their ability to harvest a variety of forms of energy such as light, mechanical and thermal energy and achieve a stable direct current output. Ferroelectric films are frequently investigated for photovoltaic applications due to their unique photovoltaic properties and bandgap-independent photovoltage, while the flexoelectric effect is an electromechanical property commonly found in solid dielectrics. Here, we effectively construct a new form of coupled nanogenerator based on a flexible BiFeO 3 ferroelectric film that combines both flexoelectric and photovoltaic effects to successfully harvest both light and vibration energies. This device converts an alternating current into a direct current and achieves a 6.2% charge enhancement and a 19.3% energy enhancement to achieve a multi-dimensional "1 + 1 > 2" coupling enhancement in terms of current, charge and energy. This work proposes a new approach to the coupling of multiple energy harvesting mechanisms in ferroelectric nanogenerators and provides a new strategy to enhance the transduction efficiency of flexible functional devices.
研究领域:
纳米技术
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材料科学
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能量收集
·
机电系统
✓ 已验证
产品关联
DOI
PubMed
高影响因子
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