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Ferroelectric‐Polymer‐Enabled Contactless Electric Power Generation in Triboelectric Nanogenerators
摘要： Triboelectric nanogenerators (TENGs) are considered as one of the most important renewable power sources for mobile electronic devices and various sensors in the Internet of Things era. However, their performance should inherently be degraded by the wearing of contact surfaces after long-term use. Here, a ferroelectric polymer is shown to enable TENGs to generate considerable electricity without contact. Ferroelectric-polymer-embedded TENG (FE-TENG) consists of indium tin oxide (ITO) electrodes, a polydimethylsiloxane (PDMS) elastomer, and a poly(vinylidene fluoride) (PVDF) polymer. In contrast to down- and non-polarization, up-polarized PVDF causes significantly large triboelectric charge, rapidly saturated voltage/current, and considerable remaining charge due to the modulated surface potential and increased capacitance. The remained triboelectric charges flow by just approaching/receding the ITO electrode to/from the PDMS without contact, which is sufficient to power light-emitting diodes and liquid crystal displays. Additionally, the FE-TENG can charge an Li-battery with a significantly reduced number of contact cycles. Furthermore, an arch-shaped FE-TENG is demonstrated to operate a wireless temperature sensor network by scavenging the irregular and random vibrations of water waves. This work provides an innovative and simple method to increase conversion efficiency and lifetime of TENGs; which widens the applications of TENG to inaccessible areas like the ocean.
关键词： contactless power generation,surface potential,capacitance,ferroelectric polymers,triboelectric nanogenerators
更新于2025-09-11 14:15:04
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Island growth mode in pulsed laser deposited ferroelectric BaTiO <sub/>3</sub> thin films: The role of oxygen pressure during deposition
摘要： Pulsed laser deposition is widely used to grow BaTiO3 thin films. We investigated the influence of oxygen pressure during growth on the topography, microstructure, and roughness of ferroelectric epitaxial BaTiO3 thin films. It also presented an analysis of the epitaxial growth mode and defects throughout the film thickness using aberration-corrected transmission electron microscopy. Although ferroelastic (twin boundary) domain walls are absent, several misfit dislocations were observed and might be the primary cause of the observed island growth mode.
关键词： barium titanate,Ferroelectric thin film,epitaxial thin film,misfit strain,crystalline defects
更新于2025-09-11 14:15:04
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Enhanced photovoltaic efficiency and persisted photoresponse switchability in LaVO3/Pb(Zr0.2Ti0.8)O3 perovskite heterostructures
摘要： For the ferroelectric photovoltaics, it is challenging to enhance the power conversion efficiency (PCE) without sacrificing the photoresponse switchability. Here, we demonstrate that enhanced PCE and good photoresponse switchability can be simultaneously achieved in perovskite heterostructures comprising narrow-gap semiconductor LaVO3 (LVO) and ferroelectric Pb(Zr0.2Ti0.8)O3 (PZT). The LVO(24 nm)/PZT(120 nm) based device exhibits a ~5-fold enhancement in PCE compared with the PZT-only based device, which is attributed to the enhanced absorption from the LVO layer and the built-in field at the LVO/PZT interface facilitating the separation of photo-generated e-h pairs. In addition, the switched photovoltage of the LVO/PZT based device is above 1 V, which is as large as that of the PZT-only based device. This persisted photoresponse switchability is obtained because the polarization can be fully switched in the LVO/PZT based devices when the LVO thickness is less than 24 nm. Our finding therefore provides a promising route for the development of the high-efficiency and highly switchable ferroelectric photovoltaic devices.
关键词： perovskite heterostructures,ferroelectric photovoltaics,LaVO3,photoresponse switchability,power conversion efficiency,Pb(Zr0.2Ti0.8)O3
更新于2025-09-11 14:15:04
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Dielectric, ferroelectric, and photovoltaic properties of La-doped Bi(Ni2/3Ta1/3)O3–PbTiO3 ceramics
摘要： Bi(Ni2/3Ta1/3)O3-PbTiO3 ceramics doped with different La contents were prepared using the conventional solid-state reaction route. The electric properties of La-doped Bi(Ni2/3Ta1/3)O3-PbTiO3 ceramics were compared with those of non-La ceramics. As the incorporated La content increased, the Curie temperature TC decreased linearly, whereas the dielectric constant ε'RT at room temperature increased. Although the remnant polarization Pr decreased, the bipolar strain S (%) increased as the La content increased, owing to phase transition from the ferroelectric phase to the paraelectric phase. The maximum bipolar strain S (0.42%) was observed in the Bi0.7La0.3(Ni2/3Ta1/3)O3-PbTiO3 ceramics. When the La content reached 50%, the ferroelectric performance deteriorated. After La was doped into the Bi(Ni2/3Ta1/3)O3-PbTiO3 ceramics, the photovoltages were markedly improved. The photovoltage (27 V) reached its maximum with 15% La content but was reduced to 0 V with 50% La doping content owing to a decline in ferroelectricity. The speed of the photovoltaic response to the incident light for this system was about 0.5 ms. Therefore, the strain and the photovoltaic properties of the La-doped Bi(Ni2/3Ta1/3)O3-PbTiO3 ceramics were markedly improved relative to those of undoped ceramics.
关键词： Ceramics,Ferroelectric,Dielectric,Photovoltaic
更新于2025-09-11 14:15:04
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Ferroelectric/photoluminescence effect in Pr-doped (Bi0.5Na0.5)TiO3–BaTiO3 thin film fabricated by the pulsed laser deposition method
摘要： In this work, (100)-oriented Pr-doped (Bi0.5Na0.5)TiO3–BaTiO3 ferroelectric/photoluminescence film was fabricated on SrRuO3-electroded Pb(Mg1/3Nb2/3)O3–PbTiO3 single-crystal substrate. The phase structure, domain, ferroelectric, and photoluminescence performance were studied. Results indicated the Pr-BNBT thin film has pure phase structure, dense microstructure, and exhibited (100) orientation out of the plane. Well-defined ferroelectric hysteresis loop with the remanent polarization of ~ 18?μC/cm2 and obvious photoluminescence emission spectrum were obtained. Based on the piezoresponse force microscopy, the ferroelectric domain structure was characterized and the domain size was ~ 100?nm. The present ferroelectric/photoluminescence multifunctional thin film has potential for multifunctional MEMS actuator and optical devices.
关键词： Thin film,Pr-doped,Ferroelectric,Photoluminescence,Pulsed laser deposition
更新于2025-09-11 14:15:04
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Fast and Simultaneous Determination of Soil Properties Using Laser-Induced Breakdown Spectroscopy (LIBS): A Case Study of Typical Farmland Soils in China
摘要： This work provides a new paradigm for designing a laser crystal requiring a broad luminescent spectrum through spontaneous polarization and local structural disorder. The grown complex ferroelectric crystals Nd-doped Pb(Mg1/3Nb2/3)O3-PbTiO3 (Nd:PMNT) have a broad emission spectrum with a full width at half-maximum value of 30 nm, much larger than typical Nd laser crystals (Nd:YAG ≈ 0.8 nm). The internal mechanism of spectral broadening in complex ferroelectric crystals was analyzed using the con?guration coordinate. The shift of the peak site in the 4F3/2 → 4I11/2 transition with temperature was a?ected by structural changes, consistent with the change in dielectric and ferroelectric properties. The family of complex ferroelectric crystals could be an abundant treasure for Nd femtosecond laser crystals requiring a broad luminescent spectrum.
关键词： local disorder,spontaneous polarization,ferroelectric crystals,Pb(Mg1/3Nb2/3)O3,Nd-doped,broad bandwidth emission
更新于2025-09-11 14:15:04
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Electro-optical dual modulation on resistive switching behavior in BaTiO <sub/>3</sub> /BiFeO <sub/>3</sub> /TiO <sub/>2</sub> heterojunction
摘要： The novel BaTiO3/BiFeO3/TiO2 multilayer heterojunction is prepared on a fluorine-doped tinoxide (FTO) substrate by the sol–gel method. The results indicate that the Pt/BaTiO3/BiFeO3/TiO2/FTO heterojunction exhibits stable bipolar resistive switching characteristic, good retention performance, and reversal characteristic. Under different pulse voltages and light fields, four stable resistance states can also be realized. The analysis shows that the main conduction mechanism of the resistive switching characteristic of the heterojunction is space charge limited current (SCLC) effect. After the comprehensive analysis of the band diagram and the P–E ferroelectric property of the multilayer heterojunction, we can deduce that the SCLC is formed by the effect of the oxygen vacancy which is controlled by ferroelectric polarization-modulated change of interfacial barrier. And the effective photo-generated carrier also plays a regulatory role in resistance state (RS), which is formed by the double ferroelectric layer BaTiO3/BiFeO3 under different light fields. This research is of potential application values for developing the multi-state non-volatile resistance random access memory (RRAM) devices based on ferroelectric materials.
关键词： multi-state resistance,resistive switching characteristic,electro-optical dual modulation,ferroelectric multilayer heterojunction
更新于2025-09-11 14:15:04
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Oxygen vacancies in the bulk and at neutral domain walls in hexagonal
摘要： We use density functional calculations to investigate the accommodation and migration of oxygen vacancies in bulk hexagonal YMnO3, and to study interactions between neutral ferroelectric domain walls and oxygen vacancies. Our calculations show that oxygen vacancies in bulk YMnO3 are more stable in the Mn-O layers than in the Y-O layers. Migration barriers of the planar oxygen vacancies are high compared to oxygen vacancies in perovskites, and to previously reported values for oxygen interstitials in h-YMnO3. The calculated polarization decreases linearly with vacancy concentration, while the out-of-plane lattice parameter expands in agreement with previous experiments. In contrast to ferroelectric perovskites, oxygen vacancies are found to be more stable in bulk than at domain walls. The tendency of oxygen vacancies to segregate away from neutral domain walls is explained by unfavorable Y-O bond lengths caused by the local strain field at the domain walls.
关键词： oxygen vacancies,ferroelectric domain walls,hexagonal YMnO3,density functional calculations,migration barriers
更新于2025-09-11 14:15:04
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AIP Conference Proceedings [Author(s) THE 6TH INTERNATIONAL CONFERENCE ON SCIENCE & ENGINEERING IN MATHEMATICS, CHEMISTRY AND PHYSICS: ScieTech18: The Nature Math - The Science - Jakarta, Indonesia (20–21 January 2018)] - Landau-Khalatnikov modified model for predicting ZnO ferroelectric properties
摘要： The Dynamic Landau-Khalatnikov (LK) model was modified to calculate polarization hysteresis curve for Zinc Oxide (ZnO) material. Ferroelectric polarization hysteresis of Zinc Oxide (ZnO) were measured by using Sawyer-Tower circuit. Landau Khalatnikov modified model was fitted to experimental data. R-Weighted Pattern (Rwp) factor was used to evaluate the precision of the model compare to experimental data. The results showed that the modified model is in a good precision compare to experimental data with Rwp< 10%.
关键词： ZnO,Ferroelectric,Landau-Devonshire
更新于2025-09-11 14:15:04
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Preparation and characterization of pyrochlore-free 0.655Pb(Mg <sub/>1/3</sub> Nb <sub/>2/3</sub> )O <sub/>3</sub> -0.345PbTiO <sub/>3</sub> piezoelectric ceramics by tape-casting process
摘要： Piezoelectric ceramics of the perovskite solid solution 0.655Pb(Mg1/3Nb2/3)O3-0.345PbTiO3 (0.655PMN-0.345PT) were synthesized by tape-casting process. Highly dense ceramics lacking parasitic pyrochlore phases were fabricated by using precursor method and adding moderate PbO. The influences from sintering temperature on the physical and electrical properties of the 0.655PMN-0.345PT ceramics were initially investigated by phase and microstructure analyses. High piezoelectric, dielectric and ferroelectric properties of d33?700 pC/N, kp?0.605, er?4770, tand ? 0.016, Pr?30.68 lC/cm2 were obtained for the specimens sintered at 1200 (cid:2)C. Compared with the traditional solid-state sintering method, the performance of ceramics formed by tape-casting achieved an improvement.
关键词： tape-casting,PMN-PT,ferroelectric properties,dielectric properties,piezoelectric properties
更新于2025-09-11 14:12:44