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Self‐Healable Black Phosphorus Photodetectors
摘要： Large‐strain multilayer actuators (MLAs) were fabricated by tape‐casting 0.91(Na1/2Bi1/2)TiO3–0.06BaTiO3–0.03AgNbO3 (NBT‐BT–3AN) lead‐free incipient piezoceramics co‐fired with Pt inner electrodes. Microstructures, dielectric properties, unipolar and bipolar strain, as well as fatigue properties of the MLAs were investigated. It was found that the actuator consisting of 15 ceramic layers with individual thicknesses of 114 μm could output a large unipolar strain of 0.3% and a dynamic displacement of 5 μm at 6 kV/mm at room temperature. It exhibited excellent cycling stability and provided a high strain of 0.23% after 107 cycles at 6 kV/mm. Moreover, these MLAs still can deliver a strain of 0.20% at 125°C.
关键词： lead‐free piezoceramics,multilayer actuators,large strain,cycling stability,temperature stability
更新于2025-09-11 14:15:04
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Recent advances toward efficient and stable tin‐based perovskite solar cells
摘要： Organic-inorganic halide perovskite solar cells (PSCs) are emerging new generation cost-effective photovoltaic technology. However, the public concern about the toxic lead contained in state-of-art PSCs has cast a shadow on their prospect for commercialization. Therefore, increasing attention has been paid to lead-free tin-based perovskites, which have the potential to achieve comparable photovoltaic performance to their lead-based counterparts. However, the development of high-performance tin-based PSCs is seriously undermined by the intrinsic poor stability of divalent tin in the perovskites. With the efforts to overcome the stability issue, encouraging ~10% efficiencies have been currently achieved. In this review, we summarize the recent advances toward efficient and stable tin-based PSCs and offer a perspective for future study.
关键词： tin,Perovskite solar cells,lead-free,Stability,efficiency
更新于2025-09-11 14:15:04
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Environmentally Robust Memristor Enabled by Lead‐Free Double Perovskite for High‐Performance Information Storage
摘要： Memristors are emerging as a rising star of new computing and information storage techniques. However, the practical applications are severely challenged by their instability toward harsh conditions, including high moisture, high temperatures, fire, ionizing irradiation, and mechanical bending. In this work, for the first time, lead-free double perovskite Cs2AgBiBr6 is utilized for environmentally robust memristors, enabling highly efficient information storage. The memory performance of the typical indium-tin-oxide/Cs2AgBiBr6/Au sandwich-like memristors is retained after 1000 switching cycles, 105 s of reading, and 104 times of mechanical bending, comparable to other halide perovskite memristors. Most importantly, the memristive behavior remains robust in harsh environments, including humidity up to 80%, temperatures as high as 453 K, an alcohol burner flame for 10 s, and 60Co γ-ray irradiation for a dosage of 5 × 105 rad (SI), which is not achieved by any other memristors and commercial flash memory techniques. The realization of an environmentally robust memristor from Cs2AgBiBr6 with a high memory performance will inspire further development of robust electronics using lead-free double perovskites.
关键词： lead free,resistive random access memory,memory,double perovskite,memristors
更新于2025-09-11 14:15:04
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Vertically-aligned lead-free BCTZY nanofibers with enhanced electrical properties for flexible piezoelectric nanogenerators
摘要： Flexible lead-free (Ba0.85Ca0.15)(Ti0.9Zr0.1)O3-0.2 mol%Y nano?bers (BCTZY NFs) were synthesized by electrospinning and their corresponding nanogenerators (NGs) with vertical alignments were fabricated. The low-temperature sintering properties of BCTZY NFs were investigated, to optimize their synthesis path and minimize the thermal energy consumption during the sintering process. The continuity, ?exibility, and stability of the BCTZ-based NFs were improved by adding Y3+. Moreover, the temperature-evolved Raman spectra displayed a high Curie temperature of 280 °C for BCTZY NFs, which was far higher than that of about 90 °C for BCTZ-based ceramic bulks, owing to the discontinuous physical property of NFs. The dielectric, ferroelectric, and piezoelectric properties of the vertically aligned BCTZY NFs/PDMS were estimated and compared with those of BCTZ NFs/PDMS composites, to verify the advantages of vertical alignments and the donor doping e?ect of Y3+. Vertically aligned BCTZY NF-based NGs showed an average VOC of 3.0 V and ISC of 85 nA by ?nger tapping, suggesting their potential applications in tiny energy harvesting.
关键词： Electrospinning,Lead-free BCTZY nano?bers,Vertical alignment,Piezoelectric nanogenerators
更新于2025-09-10 09:29:36
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Temperature-stable dielectric properties from 100 to 375?°C in system (K0.495Na0.495La0.01)(Nb0.997Cu0.0075)O3–Bi(Mg0.5Zr0.5)O3
摘要： (1-x)(K0.495Na0.495La0.01)(Nb0.997Cu0.0075)O3-xBi(Mg0.5Zr0.5)O3 (abbreviated as KNLNC-xBMZ) ceramics were designed and prepared. The phase transition, microstructure and electrical properties of the ceramics were investigated. The phase structures of the ceramics transform from orthorhombic to pseudocubic phases and the grain sizes decrease gradually with BMZ content (x) increasing. Additionally, BMZ additions can significantly enhance the dielectric temperature stability and decrease the dielectric loss of ceramics over a relatively broad temperature range. KNLNC-0.02BMZ ceramics exhibit high dielectric permittivity (er = 1542) and small variation (Der/er150 (cid:2)C B ± 15%) in dielectric permittivity from 100 to 375 (cid:2)C, and low dielectric loss (tand B 2%) in the temperature range of 100–350 (cid:2)C, which suggests that this ceramic is a candidate for high-temperature capacitor application.
关键词： (K0.5Na0.5)NbO3,Lead-free,Dielectric properties,Elevated temperature stability,Microstructure
更新于2025-09-10 09:29:36
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The effects of terbium oxide on phase transition and electronic properties of potassium-sodium niobate-based ceramics
摘要： Lead free piezoelectric ceramics 0.96K0.48Na0.52Nb0.96Sb0.04O3-0.04Bi0.5(Na0.82K0.18)0.5ZrO3-xmol%Tb4O7 (KNNS- BNKZ-xTb4O7) are prepared by solid state reaction method. The effects of Tb4O7 on phase transition, grain growth and electronic properties of the ceramics are studied. Tb4O7 (x (cid:1) 0.2) induces a phase transition from tetragonal-orthorhombic coexistence phases to pseudo-cubic one. Meanwhile, Tb4O7 could reduce grain size and lead to step-like grain growth. In addition, Tb4O7 could enhance the temperature stability of KNNS-BNKZ ceramics. For pure KNNS-BNKZ ceramics, the d33* and kp are reduced by 68.0% and 24.3%, respectively, from 30 (cid:3)C to 150 (cid:3)C. For the component x ? 0.1, they are reduced by 6.1% and 1.6%, respectively, in the same temperature range. This paper may have positive signi?cance for searching lead free piezoelectric ceramics with excellent temperature stable properties.
关键词： Piezoelectric ceramics,Phase transition,Lead free,Temperature stability
更新于2025-09-10 09:29:36
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Enhanced energy storage properties of BaTiO3-Bi0.5Na0.5TiO3 lead-free ceramics modified by SrY0.5Nb0.5O3
摘要： In this work, a novel lead-free relaxor-ferroelectric ceramics of (1-x)(0.65BaTiO3-0.35Bi0.5Na0.5TiO3)-xSrY0.5Nb0.5O3 ((1-x)BTBNT-xSYN x ? 0.02e0.12), was designed and prepared by the conventional solid state reaction method. The results show that all of the sintered samples have a perovskite structure. The Curie Temperature (Tc) moves to the low temperature side which causes the high dielectric constant at room temperature, and the ferroelectric hysteresis loop becomes slimmer and slimmer with increasing the content of SYN. Meanwhile, the optimal energy storage properties can be obtained in 0.92BTBNT-0.08SYN ceramic with an impressive discharged energy density (Wrec) of 1.36 J/cm3 under 152 kV/cm, and the charge-discharge ef?ciency reaches 74.3%. Therefore, all these results indicate that (1-x)BTBNT-xSYN lead-free ceramics can be applied for pulsed power capacitors.
关键词： SrY0.5Nb0.5O3,Energy storage,Dielectric properties,Lead-free ceramics
更新于2025-09-10 09:29:36
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Structure and property of lead-free (K,Na)NbO3–(Bi1/2Na1/2)ZrO3–CaTiO3 piezoelectric ceramics
摘要： Simultaneous improvement of piezoelectricity and temperature stability is vital for developing high-performance KNN-based lead-free materials. Here, effects of CaTiO3 on phase structure, piezoelectricity and temperature stability of (1 – x)[0.95(K0.5Na0.5)NbO3–0.05(Bi0.5Na0.5)ZrO3]–xCaTiO3–0.2%MnO2 ceramics were studied. It was found that the orthorhombic-tetragonal phase transition temperature can be gradually decreased by increasing CaTiO3 content. Particularly, the improved strain temperature stability (strain varied < 15% when measurement temperature reaches 110 °C) and enhanced electrical properties (d33 ~ 296 pC/N and strain ~ 0.14%) can be observed in the ceramics with x = 0.02. Therefore, shifting the TO?T below room temperature is an effective way to promote temperature stability and electrical properties of KNN-based piezoelectric materials.
关键词： Lead-free piezoelectric ceramics,Temperature stability,CaTiO3,Piezoelectricity,KNN-based
更新于2025-09-10 09:29:36
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Broadband Defects Emission and Enhanced Ligand Raman Scattering in 0D Cs <sub/>3</sub> Bi <sub/>2</sub> I <sub/>9</sub> Colloidal Nanocrystals
摘要： Excitonic 0D and 2D lead-halide perovskites have been recently developed and investigated as new materials for light generation. Here broadband (>1 eV) emission from newly synthesized 0D lead-free colloidal Cs3Bi2I9 nanocrystals (NCs) is reported. The nature of their emissive states as well as the relative dynamics which are currently hotly debated are investigated. In particular, it is found that the broadband emission is made by the coexistence of emissive excitons and sub-bandgap emissive trap-states. Remarkably, evidence of enhanced Raman scattering from the ligands is observed when attached to the NCs surface, an effect that is preliminarily attributed to strong exciton-ligands electronic coupling in these systems.
关键词： trap-states emission,enhanced Raman scattering,broadband emission,lead-free perovskites,0D nanocrystals
更新于2025-09-10 09:29:36
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The enhanced magnetoelectric effect and piezoelectric properties in the lead-free Bi3.15Nd0.85Ti3O12/La0.7Ca0.3MnO3 nano-multilayers composite thin films
摘要： The lead-free multiferroic nano-multilayers composite thin films were fabricated on basis of ferroelectric (FE) Bi3.15Nd0.85Ti3O12 (BNT) and ferromagnetic (FM) La0.7Ca0.3MnO3 (LCMO) parents with 8 nm/6 nm periodicity, respectively. The crystal structure, switching of polarization, magnetization and temperature dependence of magnetoelectric coupling (ME) effect for the multiferroic BNT/LCMO composite thin films were investigated in detail, respectively. Ferroelectric behavior along with an enhanced remnant polarization (2Pr) of 42 mC/cm2, saturated magnetization around 151 emu/cm3, the enhanced piezoelectric coefficient d33 of 263 pm/V and the enhanced magnetoelectric effect voltage coefficient of 72.1 mV/cm*Oe were obtained. The results show that the lead-free multiferroic films exhibit both good ferroelectric, dielectric and magnetic properties, as well as the enhanced ME effects, indicating that the coupling effects of electric and magnetic field exist in the fabricated Bi3.15Nd0.85Ti3O12/La0.7Ca0.3MnO3 (BNT/LCMO) nano-multilayer thin films, and the strong ME effect originating from the magnetic-mechanical-electric interaction and interface coupling were demonstrated. These results can be particularly important for developing nano-composite multiferroic devices.
关键词： Temperature dependence of ME effect,Lead-free BNT/LCMO nano-multilayers,Ferroelectric properties,Magnetization
更新于2025-09-10 09:29:36