Current Applied Physics最新文献

英文中文

Dependence of piezoelectric properties and thermal stability of (1–x)BiFeO3–xBaTiO3 ceramics in relation to accelerometer performance （1-x） BiFeO3-xBaTiO3陶瓷的压电性能和热稳定性与加速度计性能的关系

IF 3.1 4区物理与天体物理 Q3 MATERIALS SCIENCE, MULTIDISCIPLINARY

Current Applied Physics

Pub Date : 2025-12-01 DOI: 10.1016/j.cap.2025.11.014

Kyu-Hyun Park, Byung-Hoon Kim, Changyeon Baek, Yun-Gi Jeong, Min-Ku Lee, Gyoung-Ja Lee

This study investigates the compositional dependence of piezoelectric and thermal properties in (1–x)BiFeO₃–xBaTiO₃ ceramics and evaluates their applicability in high-temperature accelerometer applications. Four compositions (x = 0.25, 0.30, 0.33, 0.35) were synthesized and analyzed for their structural, electrical, and thermal behaviors. The x = 0.25 composition, despite a relatively low piezoelectric coefficient (∼107 pC/N), exhibited the highest mechanical quality factor (∼67) and depolarization temperature (∼450 °C), along with superior resistance to thermally and mechanically induced degradation. When used in compression-mode accelerometers, this composition showed the highest sensitivity (∼23.4 pC/g) and operated up to ∼380 °C. These results suggest that reliable high-temperature sensor performance is influenced not only by the piezoelectric coefficient but also by thermal and mechanical stability, highlighting the importance of comprehensive compositional optimization. Additionally, a strong correlation was observed between the in situ piezoelectric response of the ceramics and the temperature-dependent sensitivity of the assembled sensors.

本研究研究了（1-x） BiFeO3-xBaTiO3陶瓷中压电和热性能的成分依赖性，并评估了其在高温加速度计应用中的适用性。合成了四种组合物（x = 0.25, 0.30, 0.33, 0.35），并对其结构，电学和热行为进行了分析。x = 0.25的组合物，尽管具有相对较低的压电系数（~ 107 pC/N），但具有最高的机械质量因子（~ 67）和去极化温度（~ 450°C），以及对热和机械诱导降解的优异抵抗能力。当用于压缩模式加速度计时，该成分显示出最高的灵敏度（~ 23.4 pC/g），并且工作温度高达~ 380°C。这些结果表明，可靠的高温传感器性能不仅受到压电系数的影响，还受到热稳定性和机械稳定性的影响，突出了综合成分优化的重要性。此外，观察到陶瓷的原位压电响应与组装传感器的温度依赖灵敏度之间存在很强的相关性。

{"title":"Dependence of piezoelectric properties and thermal stability of (1–x)BiFeO3–xBaTiO3 ceramics in relation to accelerometer performance","authors":"Kyu-Hyun Park, Byung-Hoon Kim, Changyeon Baek, Yun-Gi Jeong, Min-Ku Lee, Gyoung-Ja Lee","doi":"10.1016/j.cap.2025.11.014","DOIUrl":"10.1016/j.cap.2025.11.014","url":null,"abstract":"<div><div>This study investigates the compositional dependence of piezoelectric and thermal properties in (1–<em>x</em>)BiFeO<sub>3</sub>–<em>x</em>BaTiO<sub>3</sub> ceramics and evaluates their applicability in high-temperature accelerometer applications. Four compositions (<em>x</em> = 0.25, 0.30, 0.33, 0.35) were synthesized and analyzed for their structural, electrical, and thermal behaviors. The <em>x</em> = 0.25 composition, despite a relatively low piezoelectric coefficient (<em>∼</em>107 pC/N), exhibited the highest mechanical quality factor (<em>∼</em>67) and depolarization temperature (<em>∼</em>450 °C), along with superior resistance to thermally and mechanically induced degradation. When used in compression-mode accelerometers, this composition showed the highest sensitivity (∼23.4 pC/g) and operated up to ∼380 °C. These results suggest that reliable high-temperature sensor performance is influenced not only by the piezoelectric coefficient but also by thermal and mechanical stability, highlighting the importance of comprehensive compositional optimization. Additionally, a strong correlation was observed between the in situ piezoelectric response of the ceramics and the temperature-dependent sensitivity of the assembled sensors.</div></div>","PeriodicalId":11037,"journal":{"name":"Current Applied Physics","volume":"83 ","pages":"Pages 38-45"},"PeriodicalIF":3.1,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145692524","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Effect of small concentrations of graphenic sheets on the dielectric strength of epoxy 小浓度石墨片对环氧树脂介电强度的影响

IF 3.1 4区物理与天体物理 Q3 MATERIALS SCIENCE, MULTIDISCIPLINARY

Current Applied Physics

Pub Date : 2025-12-01 DOI: 10.1016/j.cap.2025.11.012

R. Pech-Pisté , A. Can-Ortiz , D. Mary , H. Carrillo-Escalante , Z. Valdez-Nava , D. Malec , F. Avilés

Advances in high-power applications rely on the development of the insulating materials used in their power modules. However, these materials may fail under high electrical fields due to the intended or unintended presence of conductive particles. Thus, the effect of conductive particles on the dielectric properties of an epoxy polymer is investigated by adding small amounts of graphenic sheets (GSs). The role of the inclusion size was investigated by using GSs with different sizes, and supported by finite element analysis. Electrical conductivity of GS-modified epoxies exhibited only slight changes with respect to the neat epoxy. The reduction in dielectric breakdown strength (E_BR) of epoxy containing small GSs (1.2 μm diameter) was minor, while larger GSs (20.9 μm diameter) yielded a progressive reduction in E_BR as their concentration increased. Finite element simulations support that larger GSs yield higher local electric field gradients around the inclusion tips, explaining the reduction in E_BR.

大功率应用的进步依赖于其功率模块中使用的绝缘材料的发展。然而，由于有意或无意的导电颗粒的存在，这些材料可能在高电场下失效。因此，通过添加少量石墨片（GSs）来研究导电颗粒对环氧聚合物介电性能的影响。采用不同尺寸的GSs对夹杂物尺寸的影响进行了研究，并进行了有限元分析。gs改性环氧树脂的电导率与纯环氧树脂相比变化不大。含较小GSs（直径1.2 μm）的环氧树脂的介电击穿强度（EBR）降低幅度较小，而含较大GSs（直径20.9 μm）的环氧树脂的介电击穿强度随其浓度的增加而逐渐降低。有限元模拟表明，更大的GSs在夹杂尖端周围产生更高的局部电场梯度，这解释了EBR的降低。

{"title":"Effect of small concentrations of graphenic sheets on the dielectric strength of epoxy","authors":"R. Pech-Pisté , A. Can-Ortiz , D. Mary , H. Carrillo-Escalante , Z. Valdez-Nava , D. Malec , F. Avilés","doi":"10.1016/j.cap.2025.11.012","DOIUrl":"10.1016/j.cap.2025.11.012","url":null,"abstract":"<div><div>Advances in high-power applications rely on the development of the insulating materials used in their power modules. However, these materials may fail under high electrical fields due to the intended or unintended presence of conductive particles. Thus, the effect of conductive particles on the dielectric properties of an epoxy polymer is investigated by adding small amounts of graphenic sheets (GSs). The role of the inclusion size was investigated by using GSs with different sizes, and supported by finite element analysis. Electrical conductivity of GS-modified epoxies exhibited only slight changes with respect to the neat epoxy. The reduction in dielectric breakdown strength (<em>E</em><sub><em>BR</em></sub>) of epoxy containing small GSs (1.2 μm diameter) was minor, while larger GSs (20.9 μm diameter) yielded a progressive reduction in <em>E</em><sub><em>BR</em></sub> as their concentration increased. Finite element simulations support that larger GSs yield higher local electric field gradients around the inclusion tips, explaining the reduction in <em>E</em><sub><em>BR</em></sub>.</div></div>","PeriodicalId":11037,"journal":{"name":"Current Applied Physics","volume":"83 ","pages":"Pages 79-89"},"PeriodicalIF":3.1,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145748663","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

WS2–graphene heterostructures with hydrogen-controlled morphology: Interfacial charge transfer and negative photoresponse 具有氢控制形态的ws2 -石墨烯异质结构：界面电荷转移和负光响应

IF 3.1 4区物理与天体物理 Q3 MATERIALS SCIENCE, MULTIDISCIPLINARY

Current Applied Physics

Pub Date : 2025-12-01 DOI: 10.1016/j.cap.2025.11.013

Garam Bae , Wooseok Song

We report a hydrogen-assisted chemical vapor deposition (CVD) strategy for the controlled synthesis of triangular-shaped WS₂ flakes and demonstrate their integration with graphene to construct optoelectronic heterostructures. By systematically tuning the H₂ flow rate during WS₂ growth, we modulate flake density and layer thickness. Raman and XPS analyses reveal highly crystalline bilayer WS₂ with minimal contamination. Upon transferring graphene onto WS₂ flakes, we observe distinct doping-induced Raman shifts and p-type behavior in field-effect transport. Notably, the WS₂–graphene heterostructure exhibits photocurrent quenching under UV irradiation, attributed to efficient interfacial charge transfer. This study elucidates the role of H₂ in nucleation control and highlights the potential of WS₂–graphene heterostructures for photodetection applications.

我们报道了一种氢辅助化学气相沉积（CVD）策略，用于控制合成三角形WS2薄片，并证明了它们与石墨烯集成以构建光电异质结构。通过系统地调节WS2生长过程中的H2流速，我们调节了鳞片密度和层厚度。拉曼和XPS分析显示高结晶双层WS2，污染最小。在将石墨烯转移到WS2薄片上后，我们观察到不同的掺杂诱导的拉曼位移和场效应输运中的p型行为。值得注意的是，由于有效的界面电荷转移，ws2 -石墨烯异质结构在紫外线照射下表现出光电流猝灭。这项研究阐明了H2在成核控制中的作用，并强调了ws2 -石墨烯异质结构在光探测应用中的潜力。

引用次数: 0

Strain-tunable perpendicular magnetic anisotropy in equiatomic Co–Pt: Orbital-resolved design rules from first-principles 等原子Co-Pt中应变可调垂直磁各向异性：基于第一性原理的轨道分辨设计规则

IF 3.1 4区物理与天体物理 Q3 MATERIALS SCIENCE, MULTIDISCIPLINARY

Current Applied Physics

Pub Date : 2025-11-28 DOI: 10.1016/j.cap.2025.11.011

Sohee Park , Young-Kyun Kwon

Co-Pt alloys are key perpendicular-anisotropy materials for spintronic devices. Using density-functional theory with spin-orbit coupling, we systematically map how the Co:Pt ratio and biaxial strain applied along [001] (fct) and [111] (hcp) govern the magnetic anisotropy energy (MAE). The most robust perpendicular magnetic anisotropy emerges at the equiatomic 1:1 composition, where L1₀ CoPt shows

E_{MAE} \approx 0.5

meV/atom at zero strain. Under biaxial strain, fct phases display an inverted-parabolic MAE response with a sign change near

+ 2 %

tensile strain, whereas hcp CoPt maintains positive MAE over the explored strain window with a direct-parabolic trend. Orbital-resolved analysis reveals a competition between Co-driven spin-conserving channels (

L_{z}

; Bruno-type behavior) and Pt-dominated spin-flip channels (

L_{x}

), accounting for both the composition dependence and the contrasting strain responses. These insights yield practical design rules—keep the equiatomic composition and apply moderate biaxial strain—to maximize PMA and thermal stability, providing guidance for engineering high-density magnetic storage and spin-torque device platforms.

钴铂合金是自旋电子器件的关键垂直各向异性材料。利用自旋轨道耦合的密度泛函理论，我们系统地绘制了Co:Pt比和沿[001]（fct）和[111]（hcp）施加的双轴应变对磁各向异性能（MAE）的影响。在等原子1:1组成时，垂直磁各向异性最强，其中L10 CoPt在零应变下显示EMAE≈0.5 meV/原子。在双轴应变下，实相在+2%拉伸应变附近呈现反抛物型MAE响应，而hcp CoPt在探索的应变窗口内保持正MAE，呈直接抛物型趋势。轨道解析分析揭示了共驱动自旋守恒通道（Lz； bruno型行为）和pt主导的自旋翻转通道（Lx）之间的竞争，说明了成分依赖性和对比应变响应。这些见解产生了实用的设计规则-保持等原子组成并施加适度的双轴应变-以最大限度地提高PMA和热稳定性，为工程高密度磁存储和自旋扭矩器件平台提供指导。

{"title":"Strain-tunable perpendicular magnetic anisotropy in equiatomic Co–Pt: Orbital-resolved design rules from first-principles","authors":"Sohee Park , Young-Kyun Kwon","doi":"10.1016/j.cap.2025.11.011","DOIUrl":"10.1016/j.cap.2025.11.011","url":null,"abstract":"<div><div>Co-Pt alloys are key perpendicular-anisotropy materials for spintronic devices. Using density-functional theory with spin-orbit coupling, we systematically map how the Co:Pt ratio and biaxial strain applied along [001] (fct) and [111] (hcp) govern the magnetic anisotropy energy (MAE). The most robust perpendicular magnetic anisotropy emerges at the equiatomic 1:1 composition, where L1<sub>0</sub> CoPt shows <span><math><msub><mi>E</mi><mrow><mtext>MAE</mtext></mrow></msub><mo>≈</mo><mn>0.5</mn></math></span> meV/atom at zero strain. Under biaxial strain, fct phases display an inverted-parabolic MAE response with a sign change near <span><math><mo>+</mo><mn>2</mn><mspace></mspace><mi>%</mi></math></span> tensile strain, whereas hcp CoPt maintains positive MAE over the explored strain window with a direct-parabolic trend. Orbital-resolved analysis reveals a competition between Co-driven spin-conserving channels (<span><math><msub><mi>L</mi><mi>z</mi></msub></math></span>; Bruno-type behavior) and Pt-dominated spin-flip channels (<span><math><msub><mi>L</mi><mi>x</mi></msub></math></span>), accounting for both the composition dependence and the contrasting strain responses. These insights yield practical design rules—keep the equiatomic composition and apply moderate biaxial strain—to maximize PMA and thermal stability, providing guidance for engineering high-density magnetic storage and spin-torque device platforms.</div></div>","PeriodicalId":11037,"journal":{"name":"Current Applied Physics","volume":"83 ","pages":"Pages 46-52"},"PeriodicalIF":3.1,"publicationDate":"2025-11-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145748658","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Computational optimization of two-qubit entangling gates in trapped-ion systems under system frequency drift 系统频率漂移下双量子比特纠缠门的计算优化

IF 3.1 4区物理与天体物理 Q3 MATERIALS SCIENCE, MULTIDISCIPLINARY

Current Applied Physics

Pub Date : 2025-11-26 DOI: 10.1016/j.cap.2025.11.009

Woojun Lee , Chaewon Kim , Taeyoung Choi , Taehyun Kim

Quantum systems are highly sensitive to environmental noise, leading to drifts in experimental parameters. To enhance entanglement gate fidelity in multiqubit trapped-ion systems, laser amplitude modulation has proven robust against frequency drifts. In this study, we extend this technique by actively optimizing the laser amplitude sequence using a user-defined objective function. This function evaluates fidelities across a broad range of trap frequencies and identifies amplitude solutions under practical laser power constraints. We select the most robust solution—maintaining fidelity above 99.5 % across the widest frequency range—and apply it to various drift types, including linear, sinusoidal, and exponential deviations. Our approach offers a flexible framework for integrating different optimization algorithms and objective functions to maintain high-fidelity gate operations in noisy quantum environments.

量子系统对环境噪声高度敏感，导致实验参数漂移。为了提高多量子位阱离子系统的纠缠门保真度，激光调幅已被证明具有抗频率漂移的鲁棒性。在本研究中，我们通过使用用户定义的目标函数主动优化激光振幅序列来扩展该技术。该函数在广泛的陷阱频率范围内评估保真度，并在实际激光功率限制下确定振幅解决方案。我们选择最稳健的解决方案-在最宽的频率范围内保持99.5%以上的保真度-并将其应用于各种漂移类型，包括线性，正弦和指数偏差。我们的方法为集成不同的优化算法和目标函数提供了一个灵活的框架，以在嘈杂的量子环境中保持高保真的门操作。

引用次数: 0

Exchange-correlation functional effects on electronic and phononic band structures of helical Se and Te 螺旋形Se和Te的电子带和声子带结构的交换相关函数效应

IF 3.1 4区物理与天体物理 Q3 MATERIALS SCIENCE, MULTIDISCIPLINARY

Current Applied Physics

Pub Date : 2025-11-25 DOI: 10.1016/j.cap.2025.11.008

Gichan Son , Sejoong Kim , Jeongwoo Kim

Trigonal selenium (Se) and tellurium (Te), with their one-dimensional helical structures, exhibit unique chirality-driven physical phenomena. Here, we systematically investigate the influence of various XC functionals–ranging from conventional generalized gradient approximations (GGA) and meta-GGA to hybrid functionals–on the electronic and phononic band structures of Se and Te. Our calculations reveal that while meta-GGA functionals provide little improvement in electronic structures over conventional GGA, the hybrid functional HSE06 predicts a significant widening of the electronic band gap. This effect is attributed to an enhanced charge localization within the intra-chain covalent bonds, more evident in trigonal Se than in Te. Moreover, the strengthened intra-chain bonding in the HSE06 calculation leads to a hardening of high-frequency intra-chain modes and a softening of low-frequency inter-chain modes. Remarkably, trigonal Se exhibits an unusual anharmonic hardening of high-frequency optical modes under isobaric conditions, originating from the large disparity between strong intra-chain and weak inter-chain force constants.

三角形硒（Se）和碲（Te）具有一维螺旋结构，表现出独特的手性驱动物理现象。在这里，我们系统地研究了各种XC泛函——从传统的广义梯度近似（GGA）和元梯度近似（meta-GGA）到混合泛函——对Se和Te的电子和声子带结构的影响。我们的计算表明，与传统的GGA相比，meta-GGA功能对电子结构的改善很小，而混合功能HSE06预测了电子带隙的显着扩大。这种效应归因于链内共价键内的电荷定位增强，在三角形Se中比在Te中更明显。此外，HSE06计算中链内键的增强导致高频链内模式硬化，低频链间模式软化。值得注意的是，三角形Se在等压条件下表现出不同寻常的高频光学模式的非调和硬化，这是由于强链内力常数和弱链间力常数之间的巨大差异。

{"title":"Exchange-correlation functional effects on electronic and phononic band structures of helical Se and Te","authors":"Gichan Son , Sejoong Kim , Jeongwoo Kim","doi":"10.1016/j.cap.2025.11.008","DOIUrl":"10.1016/j.cap.2025.11.008","url":null,"abstract":"<div><div>Trigonal selenium (Se) and tellurium (Te), with their one-dimensional helical structures, exhibit unique chirality-driven physical phenomena. Here, we systematically investigate the influence of various XC functionals–ranging from conventional generalized gradient approximations (GGA) and meta-GGA to hybrid functionals–on the electronic and phononic band structures of Se and Te. Our calculations reveal that while meta-GGA functionals provide little improvement in electronic structures over conventional GGA, the hybrid functional HSE06 predicts a significant widening of the electronic band gap. This effect is attributed to an enhanced charge localization within the intra-chain covalent bonds, more evident in trigonal Se than in Te. Moreover, the strengthened intra-chain bonding in the HSE06 calculation leads to a hardening of high-frequency intra-chain modes and a softening of low-frequency inter-chain modes. Remarkably, trigonal Se exhibits an unusual anharmonic hardening of high-frequency optical modes under isobaric conditions, originating from the large disparity between strong intra-chain and weak inter-chain force constants.</div></div>","PeriodicalId":11037,"journal":{"name":"Current Applied Physics","volume":"82 ","pages":"Pages 22-29"},"PeriodicalIF":3.1,"publicationDate":"2025-11-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145616097","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Enhanced analog switching in Ta2O5/HfO2 bilayer resistive switching device for improved synaptic behavior in neuromorphic computing 在Ta2O5/HfO2双层电阻开关器件中增强模拟开关以改善神经形态计算中的突触行为

IF 3.1 4区物理与天体物理 Q3 MATERIALS SCIENCE, MULTIDISCIPLINARY

Current Applied Physics

Pub Date : 2025-11-20 DOI: 10.1016/j.cap.2025.11.006

Taehee Noh, Cheol Jun Kim, Jae Yeob Lee, Minkyung Ku, Tae Hoon Kim, Minu Kang, Hyeon Su Seong, Seung Jin Kang, Bo Soo Kang

Memristor with analog resistive switching (RS) characteristics has potential for effective utilization in hardware neuromorphic systems. We investigated the response by applying identical pulses to filamentary RS devices to induce synaptic functions. This study examined the effects of inserting Al₂O₃ or HfO₂ into Ta₂O₅-based RS device on its switching behavior to analyze long-term plasticity. Abrupt potentiation (or depression) behavior in Ta₂O₅ single layer structure may be inappropriate for neuromorphic applications. Thus, we proposed bilayer structures to alleviate abrupt conductance change. More linear and symmetric conductance modulation was confirmed in Ta₂O₅/HfO₂ device compared to Ta₂O₅/Al₂O₃ device: exhibiting high potential as a synaptic device for neuromorphic computing. High learning accuracy was verified in Ta₂O₅/HfO₂ device through neural network simulation. Among all devices, its RS behavior was most consistent. This could originate from fewer remaining nucleation sites for reformation of conductive filament (CF). This stable CF reformation might contribute to reliable synaptic behavior.

具有模拟电阻开关特性的忆阻器在硬件神经形态系统中具有潜在的应用价值。我们通过在丝状RS装置上施加相同的脉冲来诱导突触功能来研究反应。本研究考察了在ta2o5基RS器件中插入Al2O3或HfO2对其开关行为的影响，以分析其长期可塑性。Ta2O5单层结构中的突然增强（或抑制）行为可能不适合神经形态应用。因此，我们提出了双层结构来缓解电导的突然变化。与Ta2O5/Al2O3器件相比，Ta2O5/HfO2器件的电导调制更加线性和对称，显示出作为神经形态计算的突触器件的高潜力。通过神经网络仿真，验证了Ta2O5/HfO2器件具有较高的学习精度。在所有设备中，其RS行为是最一致的。这可能是由于用于导电丝（CF）重组的剩余成核位点较少。这种稳定的CF重组可能有助于可靠的突触行为。

{"title":"Enhanced analog switching in Ta2O5/HfO2 bilayer resistive switching device for improved synaptic behavior in neuromorphic computing","authors":"Taehee Noh, Cheol Jun Kim, Jae Yeob Lee, Minkyung Ku, Tae Hoon Kim, Minu Kang, Hyeon Su Seong, Seung Jin Kang, Bo Soo Kang","doi":"10.1016/j.cap.2025.11.006","DOIUrl":"10.1016/j.cap.2025.11.006","url":null,"abstract":"<div><div>Memristor with analog resistive switching (RS) characteristics has potential for effective utilization in hardware neuromorphic systems. We investigated the response by applying identical pulses to filamentary RS devices to induce synaptic functions. This study examined the effects of inserting Al<sub>2</sub>O<sub>3</sub> or HfO<sub>2</sub> into Ta<sub>2</sub>O<sub>5</sub>-based RS device on its switching behavior to analyze long-term plasticity. Abrupt potentiation (or depression) behavior in Ta<sub>2</sub>O<sub>5</sub> single layer structure may be inappropriate for neuromorphic applications. Thus, we proposed bilayer structures to alleviate abrupt conductance change. More linear and symmetric conductance modulation was confirmed in Ta<sub>2</sub>O<sub>5</sub>/HfO<sub>2</sub> device compared to Ta<sub>2</sub>O<sub>5</sub>/Al<sub>2</sub>O<sub>3</sub> device: exhibiting high potential as a synaptic device for neuromorphic computing. High learning accuracy was verified in Ta<sub>2</sub>O<sub>5</sub>/HfO<sub>2</sub> device through neural network simulation. Among all devices, its RS behavior was most consistent. This could originate from fewer remaining nucleation sites for reformation of conductive filament (CF). This stable CF reformation might contribute to reliable synaptic behavior.</div></div>","PeriodicalId":11037,"journal":{"name":"Current Applied Physics","volume":"83 ","pages":"Pages 1-7"},"PeriodicalIF":3.1,"publicationDate":"2025-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145645620","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Investigation of key factors influencing UV-induced quantum yield in charge management 影响电荷管理中紫外光诱导量子产率的关键因素研究

IF 3.1 4区物理与天体物理 Q3 MATERIALS SCIENCE, MULTIDISCIPLINARY

Current Applied Physics

Pub Date : 2025-11-14 DOI: 10.1016/j.cap.2025.11.007

Wenke Shi , Chenglong Yu , Jin Yan , Chenjie Miao , Siqi She , Lin Ji , Wenxian Zhang , Yuandong Jia , Yinbowen Zhang , Zeming Zhang , Yi Zhang , Hongqing Huo , Zhong Zhao

Quantum yield (QY) is a critical parameter for assessing charge management efficiency. This study established a precise measurement platform to investigate the QY of gold (Au), niobium (Nb), and silicon carbide (SiC) thin films under 255 nm ultraviolet illumination. Results demonstrated that surface contamination significantly reduces the work function (WF). Nb exhibited the lowest WF (3.89 eV) and highest QY (3.3 × 10⁻⁶). Applying a ±9 V bias increased the QY of Au by 5.8 times, a phenomenon explained by image potential barrier reduction. Furthermore, for surface-contaminated Au, the QY decreased sharply with increasing incident angle, indicating that the bulk emission mechanism predominates over the vectorial photoelectric effect. These findings provide valuable insights to help optimize space-charge management systems.

量子产率（QY）是评价电荷管理效率的重要参数。本研究建立了一个精确的测量平台，用于研究金（Au）、铌（Nb）和碳化硅（SiC）薄膜在255 nm紫外线照射下的QY。结果表明，表面污染显著降低了功函数（WF）。Nb的WF最低（3.89 eV）， QY最高（3.3 × 10−6）。施加±9 V的偏置使Au的QY增加了5.8倍，这一现象可以用图像势垒降低来解释。此外，对于表面污染的Au，随入射角的增加，QY急剧下降，表明体发射机制优于矢量光电效应。这些发现为帮助优化空间电荷管理系统提供了有价值的见解。

引用次数: 0

Graphene electrodes decorated with starch-derived carbon dots for flexible supercapacitors 用淀粉衍生碳点装饰的石墨烯电极，用于柔性超级电容器

IF 3.1 4区物理与天体物理 Q3 MATERIALS SCIENCE, MULTIDISCIPLINARY

Current Applied Physics

Pub Date : 2025-11-10 DOI: 10.1016/j.cap.2025.11.005

V.C. Suchitra , R. Athira , V. Anunanda , Sithara , S.P. Vaiga Sagar , P.C. Rilu Fathima , K. Fathima Rameeza , T.A. Ramseena , N.N. Binitha

Flexible supercapacitors are essential for wearable electronics due to their mechanical resilience. This study uses soluble starch, a carbohydrate-based milling agent, for the mechanochemical exfoliation of graphite into few-layered, less-defective graphene. Hydrothermal treatment of the milled mixture containing starch yields carbon dot (CD)-decorated graphene. Material characterization confirms the turbostratic graphene structure, its edge functionalities, and CD distribution over the sheets. Electrochemical evaluation in a three-electrode system shows a specific capacitance of 614.1 F/g at 3 A/g, low charge transfer resistance, 98.3 % coulombic efficiency, and 100 % capacitance retention over 12,000 cycles. CD/graphene follows more of a pseudocapacitive mechanism with 80 % diffusive contribution. A flexible symmetric device using CD/graphene achieves 99.6 F/g (139.45 mF/cm²) specific capacitance, 13.8 Wh/kg energy density, and 714.3 W/kg power density. It retains 100 % capacitance after 2000 cycles and performs reliably under bending, twisting and folding. Three devices in series successfully light a green LED and decorative light, demonstrating real-world applicability.

由于其机械弹性，柔性超级电容器对可穿戴电子产品至关重要。本研究使用可溶性淀粉（一种基于碳水化合物的磨粉剂）将石墨机械化学剥落成层数少、缺陷少的石墨烯。水热处理含有淀粉的研磨混合物可以得到碳点（CD）修饰的石墨烯。材料表征证实了石墨烯的涡轮层结构、边缘功能和CD在薄片上的分布。电化学评价表明，在3a /g下，三电极系统的比电容为614.1 F/g，电荷转移电阻低，库仑效率98.3%，在12,000次循环中电容保持率100%。CD/石墨烯更多地遵循伪电容机制，具有80%的扩散贡献。采用CD/石墨烯的柔性对称器件可实现99.6 F/g （139.45 mF/cm2）比电容、13.8 Wh/kg能量密度和714.3 W/kg功率密度。经过2000次循环后，它保持100%的电容，在弯曲，扭曲和折叠下性能可靠。三个器件串联成功点亮绿色LED和装饰灯，展示了现实世界的适用性。

{"title":"Graphene electrodes decorated with starch-derived carbon dots for flexible supercapacitors","authors":"V.C. Suchitra , R. Athira , V. Anunanda , Sithara , S.P. Vaiga Sagar , P.C. Rilu Fathima , K. Fathima Rameeza , T.A. Ramseena , N.N. Binitha","doi":"10.1016/j.cap.2025.11.005","DOIUrl":"10.1016/j.cap.2025.11.005","url":null,"abstract":"<div><div>Flexible supercapacitors are essential for wearable electronics due to their mechanical resilience. This study uses soluble starch, a carbohydrate-based milling agent, for the mechanochemical exfoliation of graphite into few-layered, less-defective graphene. Hydrothermal treatment of the milled mixture containing starch yields carbon dot (CD)-decorated graphene. Material characterization confirms the turbostratic graphene structure, its edge functionalities, and CD distribution over the sheets. Electrochemical evaluation in a three-electrode system shows a specific capacitance of 614.1 F/g at 3 A/g, low charge transfer resistance, 98.3 % coulombic efficiency, and 100 % capacitance retention over 12,000 cycles. CD/graphene follows more of a pseudocapacitive mechanism with 80 % diffusive contribution. A flexible symmetric device using CD/graphene achieves 99.6 F/g (139.45 mF/cm<sup>2</sup>) specific capacitance, 13.8 Wh/kg energy density, and 714.3 W/kg power density. It retains 100 % capacitance after 2000 cycles and performs reliably under bending, twisting and folding. Three devices in series successfully light a green LED and decorative light, demonstrating real-world applicability.</div></div>","PeriodicalId":11037,"journal":{"name":"Current Applied Physics","volume":"81 ","pages":"Pages 57-65"},"PeriodicalIF":3.1,"publicationDate":"2025-11-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145526601","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Magical distribution of electron states for Emission in Si-Ge-Si Multiple Quantum Wells Si-Ge-Si多量子阱中发射电子态的神奇分布

IF 3.1 4区物理与天体物理 Q3 MATERIALS SCIENCE, MULTIDISCIPLINARY

Current Applied Physics

Pub Date : 2025-11-07 DOI: 10.1016/j.cap.2025.11.004

Zhong-Mei Huang , Wei-Qi Huang , Yin-Lian Li , Fei-Yian Yuang , Shi-Rong Liu

The Si-Ge-Si multiple quantum wells (MQW) is fabricated by pulsed laser deposition (PLD) method, in which the nanolayers are crystallized in the annealing and the coherent electron beam irradiation processes. It is discovered in the simulating calculation that the magical distribution of electron states with multi-peak shape occurs and the direct-gap structure is obtained in the MQW. It is interesting that the enhanced emission peaks with the multi-longitudinal-mode near 1150 and 1550 nm are observed in the photoluminescence (PL) spectra measured in the MQW, which have the emission characteristics of direct-gap near Si band edge or Ge band edge due to elevation of conduction valley at X point or L point over the valley at Γ point in the quantum system. The results in experiment and calculation exhibit that the peaks number in the multi-longitudinal-mode emission increases with increasing MQW number, and the emission wavelength can enter into the optic-communication windows by changing MQW number near Ge band edge. The new effects are discovered, in which the physical model from the multi-quantum-well to the electron states with multi-peak shape for better emission is built according to the data in the investigation. This kind of emission with the multi-longitudinal-mode will have a good application in ultra-fast laser through locking modes and in optical source on silicon chip for optic-communication.

采用脉冲激光沉积（PLD）方法制备了Si-Ge-Si多量子阱（MQW），并在退火和相干电子束辐照过程中使纳米层结晶。在模拟计算中发现，MQW中出现了多峰状电子态的神奇分布，并获得了直接间隙结构。有趣的是，在MQW测量的光致发光（PL）光谱中，在1150 nm和1550 nm附近观测到多纵向模式的增强发射峰，由于量子系统中X点的导谷升高或L点的导谷高于Γ点的导谷，它们在Si带边缘或Ge带边缘附近具有直接间隙的发射特征。实验和计算结果表明，多纵模发射峰数随着MQW数的增加而增加，并且通过改变Ge带边缘附近的MQW数可以使发射波长进入光通信窗口。发现了新的效应，根据研究数据建立了从多量子阱到多峰形状电子态的物理模型，以获得更好的发射效果。这种多纵模发射将在超快锁模激光器和光通信用硅片光源中有很好的应用。

{"title":"Magical distribution of electron states for Emission in Si-Ge-Si Multiple Quantum Wells","authors":"Zhong-Mei Huang , Wei-Qi Huang , Yin-Lian Li , Fei-Yian Yuang , Shi-Rong Liu","doi":"10.1016/j.cap.2025.11.004","DOIUrl":"10.1016/j.cap.2025.11.004","url":null,"abstract":"<div><div>The Si-Ge-Si multiple quantum wells (MQW) is fabricated by pulsed laser deposition (PLD) method, in which the nanolayers are crystallized in the annealing and the coherent electron beam irradiation processes. It is discovered in the simulating calculation that the magical distribution of electron states with multi-peak shape occurs and the direct-gap structure is obtained in the MQW. It is interesting that the enhanced emission peaks with the multi-longitudinal-mode near 1150 and 1550 nm are observed in the photoluminescence (PL) spectra measured in the MQW, which have the emission characteristics of direct-gap near Si band edge or Ge band edge due to elevation of conduction valley at X point or L point over the valley at Γ point in the quantum system. The results in experiment and calculation exhibit that the peaks number in the multi-longitudinal-mode emission increases with increasing MQW number, and the emission wavelength can enter into the optic-communication windows by changing MQW number near Ge band edge. The new effects are discovered, in which the physical model from the multi-quantum-well to the electron states with multi-peak shape for better emission is built according to the data in the investigation. This kind of emission with the multi-longitudinal-mode will have a good application in ultra-fast laser through locking modes and in optical source on silicon chip for optic-communication.</div></div>","PeriodicalId":11037,"journal":{"name":"Current Applied Physics","volume":"82 ","pages":"Pages 15-21"},"PeriodicalIF":3.1,"publicationDate":"2025-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145616187","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

首页上一页

下一页尾页

类型

全部化学•材料生命科学医学物理工程技术环境•农林材料科学地球科学法学管理学化学环境科学与生态学计算机科学教育学经济学农林科学人文科学生物学数学物理与天体物理心理学综合性期刊其他工业工程理学历史学农学文学信息工程

数据库

全部 ACS Publications Elsevier ieeexplore Springer The Royal Society of Chemistry Wiley

期刊

Current Applied Physics

全部 Acc. Chem. Res. ACS Applied Bio Materials ACS Appl. Electron. Mater. ACS Appl. Energy Mater. ACS Appl. Mater. Interfaces ACS Appl. Nano Mater. ACS Appl. Polym. Mater. ACS BIOMATER-SCI ENG ACS Catal. ACS Cent. Sci. ACS Chem. Biol. ACS Chemical Health & Safety ACS Chem. Neurosci. ACS Comb. Sci. ACS Earth Space Chem. ACS Energy Lett. ACS Infect. Dis. ACS Macro Lett. ACS Mater. Lett. ACS Med. Chem. Lett. ACS Nano ACS Omega ACS Photonics ACS Sens. ACS Sustainable Chem. Eng. ACS Synth. Biol. Anal. Chem. BIOCHEMISTRY-US Bioconjugate Chem. BIOMACROMOLECULES Chem. Res. Toxicol. Chem. Rev. Chem. Mater. CRYST GROWTH DES ENERG FUEL Environ. Sci. Technol. Environ. Sci. Technol. Lett. Eur. J. Inorg. Chem. IND ENG CHEM RES Inorg. Chem. J. Agric. Food. Chem. J. Chem. Eng. Data J. Chem. Educ. J. Chem. Inf. Model. J. Chem. Theory Comput. J. Med. Chem. J. Nat. Prod. J PROTEOME RES J. Am. Chem. Soc. LANGMUIR MACROMOLECULES Mol. Pharmaceutics Nano Lett. Org. Lett. ORG PROCESS RES DEV ORGANOMETALLICS J. Org. Chem. J. Phys. Chem. J. Phys. Chem. A J. Phys. Chem. B J. Phys. Chem. C J. Phys. Chem. Lett. Analyst Anal. Methods Biomater. Sci. Catal. Sci. Technol. Chem. Commun. Chem. Soc. Rev. CHEM EDUC RES PRACT CRYSTENGCOMM Dalton Trans. Energy Environ. Sci. ENVIRON SCI-NANO ENVIRON SCI-PROC IMP ENVIRON SCI-WAT RES Faraday Discuss. Food Funct. Green Chem. Inorg. Chem. Front. Integr. Biol. J. Anal. At. Spectrom. J. Mater. Chem. A J. Mater. Chem. B J. Mater. Chem. C Lab Chip Mater. Chem. Front. Mater. Horiz. MEDCHEMCOMM Metallomics Mol. Biosyst. Mol. Syst. Des. Eng. Nanoscale Nanoscale Horiz. Nat. Prod. Rep. New J. Chem. Org. Biomol. Chem. Org. Chem. Front. PHOTOCH PHOTOBIO SCI PCCP Polym. Chem.

﹀