Materials Today Physics最新文献_第10页

Probing atomic-scale origins of frequency-dependent phonon transport in aluminum gallium oxide ternary alloy films 铝镓氧化三元合金薄膜中频率相关声子输运的原子尺度起源探测

IF 9.7 2区材料科学 Q1 MATERIALS SCIENCE, MULTIDISCIPLINARY

Materials Today Physics

Pub Date : 2026-01-01 Epub Date: 2025-12-22 DOI: 10.1016/j.mtphys.2025.101994

Xinglin Xiao , Rongkun Chen , Xiangyu Xu , Xiaolong Li , Guoliang Ma , Yali Mao , Yuan Li , Xing Hu , Haoyang Peng , Jianing Liang , Shujuan Liu , Kelvin H.L. Zhang , Shiqian Hu , Chao Yuan

β-(Al_xGa_1-x)₂O₃ (AGO) alloys offer transformative potential for high-power electronics, yet their thermal properties necessitate further research to enable electro-thermal co-design. Persistent challenges in accurately modeling atomic-scale disorder and in synthesizing compositionally graded AGO ternary alloy thin films fundamentally limit the mechanistic elucidation of alloy phonon transport through synergistic theory-experiment frameworks. By integrating neural evolution potential molecular dynamics with transient thermoreflectance experiments, we resolve the spectral phonon behaviors across million-atom disordered systems. Results reveal a two-regime thermal conductivity (TC) reduction: a sharp 43 % drop at x = 0–0.1 (7–4 W m⁻¹ K⁻¹) driven by suppressed low-frequency phonons (0–10 THz, 76 % loss), followed by a gradual 18 % decline at x = 0.1–0.5 (4–3.3 W m⁻¹ K⁻¹) via mid-frequency (10–15 THz) spectral compensation. Crystal orbital Hamilton population analysis reveals that the Al-O bond is strengthened and a reduction in atomic mass elevates the mid/high-frequency phonon density of states (PDOS), slowing TC degradation. The Virtual Crystal Approximation (VCA) simulation-based fitting to molecular dynamics results quantitatively resolves the dominance of strain-field scattering (>60 %) over mass-defect effects, a phenomenon driven by Al-induced bond-length mismatch and lattice symmetry breaking. This mechanism is experimentally corroborated by Raman spectral extinction of Ga₂O₃-characteristic phonon modes for x ≥ 0.1. Similarly, the thermal boundary conductance (TBC) of AGO/Al₂O₃ exhibits concentration-independent stability (<10 % variation for x > 0.1), resulting from PDOS redistribution-driven spectral coupling. This work provides atomic-scale insights into phonon engineering strategies for AGO-based power electronics, highlighting the critical role of frequency-resolved phonon manipulation in electro-thermal co-design.

β-(AlxGa1-x)2O3 （AGO）合金为大功率电子器件提供了变革潜力，但其热性能需要进一步研究以实现电热协同设计。在精确模拟原子尺度紊乱和合成成分梯度AGO三元合金薄膜方面持续存在的挑战从根本上限制了通过协同理论-实验框架对合金声子输运的机理解释。通过将神经进化势分子动力学与瞬态热反射实验相结合，研究了百万原子无序系统中声子的光谱行为。结果表明，在x = 0-0.1 （7 ~ 4 W·m-1·K-1）时，通过抑制低频声子（0 ~ 10太赫兹，损耗76%），热导率急剧下降43%；在x = 0.1-0.5 （4 ~ 3.3 W·m-1·K-1）时，通过中频（10 ~ 15太赫兹）频谱补偿，热导率逐渐下降18%。晶体轨道Hamilton居群分析表明，Al-O键得到加强，原子质量的降低提高了中/高频声子态密度（PDOS），减缓了TC的降解。基于虚拟晶体近似（VCA）模拟的分子动力学拟合结果定量地解决了应变场散射（> 60%）对质量缺陷效应的主导作用，这是由al诱导的键长失配和晶格对称性破坏驱动的现象。当x≥0.1时，ga2o3特征声子模式的拉曼光谱消光实验证实了这一机制。同样，由于PDOS再分布驱动的光谱耦合，AGO/Al2O3的热边界电导（TBC）表现出与浓度无关的稳定性（在x >； 0.1时变化<； 10%）。这项工作为基于ago的电力电子的声子工程策略提供了原子尺度的见解，突出了频率分辨声子操作在电热协同设计中的关键作用。

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引用次数: 0

Advances in bionic vision research based on optoelectronic memristors: materials, device properties and systems 基于光电忆阻器的仿生视觉研究进展：材料、器件性能和系统

IF 9.7 2区材料科学 Q1 MATERIALS SCIENCE, MULTIDISCIPLINARY

Materials Today Physics

Pub Date : 2026-01-01 Epub Date: 2025-12-24 DOI: 10.1016/j.mtphys.2025.102000

Jinchang Meng, Ningqiang Shi, Tingwei Yan, Yang Wan, Ling Li

Optoelectronic Memristors (OMs) represent a significant hardware foundation for constructing artificial visual neural networks. As a novel class of integrated sensory-memory-computing devices, they hold great promise for overcoming the bottlenecks inherent in traditional von Neumann computing architectures. Leveraging desirable characteristics such as high bandwidth and low power consumption, OMs integrate optical sensing, information storage, and neuromorphic computing functionalities. This integration endows them with substantial potential for brain-inspired visual neural systems. This review summarizes recent progress in OMs, focusing on materials and physical mechanisms, performance metrics, and multi-mode in-sensor computing applications. The applications of oxides, two-dimensional materials, chalcogenides, and biomaterials in OMs are detailed, with corresponding operating mechanisms analyzed. Subsequently, the fundamental electrical properties and optoelectronic response characteristics of OMs are analyzed. Furthermore, synaptic plasticity in OMs is discussed, encompassing short-term/long-term plasticity learning rules and other neuromorphic functionalities emulation, based on their inherent neuromorphic properties. Additionally, applications of OMs in Boolean logic operations, artificial vision systems, and wearable neuromorphic devices are examined. Conclusively, the primary advantages, persistent challenges, and emerging research trajectories of OMs are synthesized. This analysis establishes foundational insights for advancing brain-inspired neural systems.

光电忆阻器是构建人工视觉神经网络的重要硬件基础。作为一种新型的集成感觉-记忆-计算设备，它们有望克服传统冯·诺依曼计算体系结构中固有的瓶颈。利用高带宽和低功耗等理想特性，OMs集成了光传感、信息存储和神经形态计算功能。这种整合使它们具有巨大的潜力来开发大脑启发的视觉神经系统。本文综述了OMs的最新进展，重点是材料和物理机制、性能指标和多模式传感器内计算应用。详细介绍了氧化物、二维材料、硫族化合物和生物材料在OMs中的应用，并分析了其作用机理。随后，分析了OMs的基本电学特性和光电响应特性。此外，本文还讨论了OMs的突触可塑性，包括短期/长期可塑性学习规则和其他基于其固有神经形态特性的神经形态功能模拟。此外，OMs在布尔逻辑运算、人工视觉系统和可穿戴神经形态设备中的应用也进行了研究。最后，综合了OMs的主要优势、持续挑战和新兴研究轨迹。这一分析为推进大脑启发的神经系统建立了基础见解。

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引用次数: 0

Realizing overall trade-off of giant caloric effect, wide working temperature range and ultrahigh cyclic stability in Ni-Co-Mn-Ti-B multiferroic phase transformation alloy 实现了Ni-Co-Mn-Ti-B多铁相变合金巨热效应、宽工作温度范围和超高循环稳定性的综合权衡

IF 9.7 2区材料科学 Q1 MATERIALS SCIENCE, MULTIDISCIPLINARY

Materials Today Physics

Pub Date : 2026-01-01 Epub Date: 2025-12-24 DOI: 10.1016/j.mtphys.2025.102001

Ziqi Guan , Haoxuan Liu , Hongyuan Tang , Yanze Wu , Xiaowen Hao , Zhenzhuang Li , Jing Bai , Yafei Kuang , Xing Lu , Liang Zuo

Solid-state refrigeration materials have attracted considerable attention due to their promising applications in low-carbon refrigeration technology. Given that the refrigeration performances of solid-state refrigeration materials are intrinsically correlated or even inversely related, an overall trade-off is necessitated. Here, we present a directionally solidified (Ni₃₇Co₁₃Mn_33.8Ti_16.2)_98.7B_1.3 alloy that exhibits outstanding comprehensive properties. Its fracture compressive strain and strength are 19.0 % and 2454 MPa at room temperature, respectively. Under external field excitation, the alloy demonstrates a giant elastocaloric adiabatic temperature change of 30.1 K and can also yield a large magnetic entropy change of 33.7 J kg⁻¹ K⁻¹. More importantly, the combination of multiple caloric effects extends the working temperature range of the present alloy over 240 K. Furthermore, a large elastocaloric adiabatic temperature change between loading and unloading during fatigue is about 11 K and can be maintained for more than 73,000 cycles. Experimental and first-principles calculations reveal that the outstanding comprehensive properties of the present alloy are primarily attributed to the synergistic interaction of large lattice vibration entropy, strong preferred orientation, second phase strengthening, and grain boundary strengthening. Such a combination renders the present alloy state-of-the-art refrigeration functional behavior and is expected to benefit the practical applications of solid-state refrigeration.

固态制冷材料因其在低碳制冷技术中的应用前景而备受关注。鉴于固态制冷材料的制冷性能是内在相关的，甚至是负相关的，因此需要一个整体的权衡。本文制备了一种具有优异综合性能的定向凝固（Ni37Co13Mn33.8Ti16.2）98.7B1.3合金。室温下，其断裂抗压应变和强度分别为19.0%和2454 MPa。在外场激励下，合金表现出30.1 K的巨大热弹性绝热温度变化和33.7 J kg−1 K−1的大磁熵变化。更重要的是，多种热效应的结合将合金的工作温度范围扩大到240 K以上。此外，在疲劳期间，加载和卸载之间的大弹性热绝热温度变化约为11 K，可以保持超过73,000次循环。实验和第一性原理计算表明，大晶格振动熵、强择优取向、第二相强化和晶界强化的协同作用是合金优异的综合性能的主要原因。这样的组合使目前的合金具有最先进的制冷功能行为，并有望有利于固态制冷的实际应用。

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引用次数: 0

Observation of ultra-long range topological proximity effect induced by interfacial band inversion 界面带反演引起的超远程拓扑邻近效应的观察

IF 9.7 2区材料科学 Q1 MATERIALS SCIENCE, MULTIDISCIPLINARY

Materials Today Physics

Pub Date : 2026-01-01 Epub Date: 2026-01-07 DOI: 10.1016/j.mtphys.2026.102012

Bin Li , Qiangsheng Lu , Xiangbin Cai , Shuigang Xu , Yipu Xia , Wingkin Ho , Ning Wang , Chang Liu , Maohai Xie

A topological phase transition (TPT) is realized in rhombohedral Sb

_{2}

Se

_{3}

via interfacial proximity. Molecular beam epitaxy (MBE) enables the epitaxial growth of Sb

_{2}

Se

_{3}

on Bi

_{2}

Se

_{3}

, a strong topological insulator (STI), and on In

_{2}

Se

_{3}

, an ordinary insulator (OI). Angle-resolved photoemission spectroscopy (ARPES) reveals a Dirac cone in Sb

_{2}

Se

_{3}

/Bi

_{2}

Se

_{3}

up to 15 nm thickness, in dramatic contrast to the full bandgap observed in Sb

_{2}

Se

_{3}

/In

_{2}

Se

_{3}

. Structural characterization confirms strain-free interfaces and identical crystal phases. A

k \cdot p

model has been developed to interpret the ultra-long range proximity effect. These results demonstrate ultra-long range topological order propagation driven by interfacial band hybridization, resolving longstanding debates on the energy band topology of Sb

_{2}

Se

_{3}

and establishing heterostructuring as a route to engineer quantum phases.

在菱面体Sb2Se3中，通过界面接近实现了拓扑相变。分子束外延（MBE）可以使Sb2Se3在强拓扑绝缘体Bi2Se3 （STI）和普通绝缘体In2Se3 （OI）上外延生长。角分辨光发射光谱（ARPES）显示，Sb2Se3/Bi2Se3中存在厚度达15 nm的狄拉克锥，与Sb2Se3/In2Se3中观察到的全带隙形成鲜明对比。结构表征证实了无应变界面和相同的晶相。建立了一个k⋅p模型来解释超远程接近效应。这些结果证明了界面带杂化驱动的超长距离拓扑顺序传播，解决了Sb2Se3的能带拓扑结构的长期争论，并建立了异质结构作为工程量子相的途径。

引用次数: 0

Probing phonon mean-free-path distribution via thickness-dependent thermal conductivity in epitaxial SrSnO3 利用厚度相关热导率探测外延SrSnO3声子平均自由程分布

IF 9.7 2区材料科学 Q1 MATERIALS SCIENCE, MULTIDISCIPLINARY

Materials Today Physics

Pub Date : 2026-01-01 Epub Date: 2025-12-16 DOI: 10.1016/j.mtphys.2025.101991

Chi Zhang , Fengdeng Liu , Donghwan Kim , Xiaotian Xu , Silu Guo , Yankai Pei , K. Andre Mkhoyan , Tianli Feng , Bharat Jalan , Xiaojia Wang

We report the thickness-dependent thermal conductivity of ultra-wide bandgap (UWBG) strontium stannate (SrSnO₃, SSO) thin films and reconstruct the phonon mean-free-path (MFP) distribution directly from experimental data. A series of SSO films with thicknesses ranging from 10 to 100 nm was grown using hybrid molecular beam epitaxy. The through-plane thermal conductivities (Λ_SSO) were measured with time-domain thermoreflectance (TDTR), together with prior TDTR measurements of a 350-nm film. A pronounced thickness dependence is observed, where reducing the thickness from 350 nm to 100 nm and 10 nm suppresses Λ_SSO by ∼30% and 70%, respectively. Our analyses decompose Λ_SSO into particle-like (population) and wave-like (coherence) contributions based on the idea of Wigner transport formulation. Assuming a thickness-independent coherence contribution, we isolate the population contribution and reconstruct its phonon MFP distribution by adopting an integral MFP formalism. This approach enables direct determination of the MFP spectrum from experimental data of thickness-dependent Λ_SSO without relying on phonon dispersion calculations or scattering models. Excellent agreement in Λ_SSO between model calculation and experimental data is achieved, indicating that phonons with MFPs below 100 nm contribute over 80% of bulk thermal conductivity, with the full MFP spectrum converged at ∼170 nm. This approach provides an experimental pathway to study particle-like and wave-like thermal transport and serves as an example of reconstructing phonon MFP spectra in materials with strong lattice anharmonicity. These findings yield critical insights into structure-thermal property relationships and offer guidance for the design and optimization of UWBG perovskite-based electronic devices under nanoscale thermal constraints.

我们报道了超宽带隙（UWBG）锡酸锶（SrSnO3， SSO）薄膜的厚度相关热导率，并直接从实验数据重建声子平均自由程（MFP）分布。采用杂化分子束外延的方法，制备了厚度在10 ~ 100nm之间的单点硅薄膜。通过时域热反射（TDTR）测量了通过平面的热导率（ΛSSO），并结合先前对350nm薄膜的TDTR测量。观察到明显的厚度依赖性，其中将厚度从350 nm减少到100 nm和10 nm分别抑制ΛSSO约30%和70%。我们的分析将ΛSSO分解为基于Wigner输运公式思想的类粒子（种群）和类波（相干）贡献。假设相干贡献与厚度无关，我们分离种群贡献并采用积分MFP形式重建其声子MFP分布。这种方法可以从厚度相关ΛSSO的实验数据中直接确定MFP谱，而不依赖于声子色散计算或散射模型。在ΛSSO模型计算和实验数据之间取得了很好的一致性，表明MFP低于100 nm的声子贡献了80%以上的体热导率，整个MFP谱在~ 170 nm收敛。该方法为研究类粒子和类波热输运提供了一条实验途径，并为在具有强晶格非调和性的材料中重建声子MFP谱提供了一个例子。这些发现对结构-热性能关系产生了重要的见解，并为纳米级热约束下UWBG钙钛矿基电子器件的设计和优化提供了指导。

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引用次数: 0

PbS quantum dots-derived gradient interfaces unify doping and strain for enhanced Bi0.5Sb1.5Te3 thermoelectrics PbS量子点衍生梯度界面统一掺杂和应变增强Bi0.5Sb1.5Te3热电材料

IF 9.7 2区材料科学 Q1 MATERIALS SCIENCE, MULTIDISCIPLINARY

Materials Today Physics

Pub Date : 2026-01-01 Epub Date: 2025-12-06 DOI: 10.1016/j.mtphys.2025.101975

Min Ruan , Minwen Yang , Qing Cao , Wenjie Li , Yanqi Huang , Zehao Lin , Jingyi Lyu , Zeqing Hu , Jing Shuai

Enhancing near-room-temperature p-type (Bi, Sb)₂Te₃ has long been hindered by an intrinsic trade-off in nano structure interfacial engineering: incoherent interfaces strongly scatter phonons but penalize carrier transport, whereas coherent interfaces preserve mobility but provide limited phonon scattering. Here we propose an in-situ multifunctional interfacial strategy enabled by PbS quantum dots (QDs), which self-assembles a chemically graded layer and strong localized strain fields around the QDs during densification. High-resolution electron energy loss spectroscopy (EELS) evidences a continuous compositional gradient that acts as a broad-spectrum phonon scatterer and an intrinsic dopant reservoir. Geometrical phase analysis (GPA) directly reveals intense, localized strain hotspots that lower the formation energy of host-type acceptor defects and modulate the electronic density of states. Experimentally, even 0.1 wt% PbS QDs increase the hole concentration from 1.2 × 10¹⁹ cm⁻³ to 2.4 × 10¹⁹ cm⁻³. Despite moderate decreases in mobility and Seebeck coefficient, a room-temperature power factor of ∼41 μW cm⁻¹ K⁻² is achieved. Subsequent Ga co-doping fine-tunes the carrier density and further suppresses the lattice thermal conductivity, yielding a ZT_max of 1.33 at 350 K (∼20 % higher than the pristine sample) and ZT_ave of 1.12 from 300 to 475 K. Control experiments with elemental Pb, S and micrometer-sized PbS indicate that nanoscale morphology and the resulting in-situ graded interface, rather than chemical composition alone, are essential to the observed synergistic enhancement. This work establishes a generalizable paradigm that intrinsically unifies chemical doping, strain engineering, and multiscale phonon blocking within a single interfacial zone to overcome electron-phonon coupling constraints in near-room-temperature thermoelectric.

增强近室温p型（Bi, Sb）2Te3长期以来一直受到纳米结构界面工程中固有权衡的阻碍：非相干界面强烈散射声子但不利于载流子输运，而相干界面保持迁移性但提供有限的声子散射。本文提出了一种基于PbS量子点（QDs）的原位多功能界面策略，该策略在致密化过程中自组装化学梯度层和QDs周围的强局域应变场。高分辨率电子能量损失谱（EELS）证明了一个连续的成分梯度，它作为一个广谱声子散射体和一个内在的掺杂库。几何相位分析（GPA）直接揭示了强烈的局部应变热点，这些热点降低了宿主型受体缺陷的形成能量并调节了态的电子密度。实验表明，即使0.1 wt% PbS量子点也能使空穴浓度从1.2 × 1019 cm−3增加到2.4 × 1019 cm−3。尽管迁移率和塞贝克系数略有下降，但室温功率因数达到了~ 41 μW cm−1 K−2。随后的Ga共掺杂微调了载流子密度，进一步抑制了晶格热导率，在350 K时产生的ZTmax为1.33（比原始样品高20%），在300至475 K时产生的ZTave为1.12。元素Pb、S和微米级PbS的对照实验表明，纳米尺度的形貌和生成的原位梯度界面，而不仅仅是化学成分，是观察到的协同增强的关键。这项工作建立了一个可推广的范例，该范例内在地统一了化学掺杂，应变工程和单一界面区域内的多尺度声子阻塞，以克服近室温热电中的电子-声子耦合约束。

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引用次数: 0

Layered-tunnel structure enables high defect tolerance for coexistence of anomalous thermal quenching and mechanoluminescence in Sr2ZnSi2O7:Mn2+ 层状隧道结构使Sr2ZnSi2O7:Mn2+在异常热猝灭和机械发光的同时具有较高的缺陷容忍度

IF 9.7 2区材料科学 Q1 MATERIALS SCIENCE, MULTIDISCIPLINARY

Materials Today Physics

Pub Date : 2026-01-01 Epub Date: 2025-12-05 DOI: 10.1016/j.mtphys.2025.101958

Pan Zhang , Xinyi Jiang , Jingyi Gao , Jiabin Dong , Fan Yang , Tongqing Sun , Li Wu , Yongfa Kong , Yi Zhang , Jingjun Xu

Defect states play an increasingly critical role in regulating the luminescent properties of modern optical materials, as their positions and distributions directly dictate the materials’ luminescent behaviors. A long-standing challenge exists in luminescent materials: elastic-mechanoluminescent (ML) materials rely on shallow trap levels, while photoluminescent materials with high thermal stability require deep trap levels. These conflicting trap level demands make it extremely difficult to simultaneously integrate ML and excellent thermal stability in a single material. Herein, we demonstrate a solution through a layered-tunnel silicate, Sr₂ZnSi₂O₇ (SZS), whose wide bandgap and unique structure offer exceptional defect tolerance. When doped with Mn²⁺, Sr₂ZnSi₂O₇:Mn²⁺ (SZSM) successfully integrates both ML and anomalous thermal quenching properties. The defect-tolerant host allows for the formation of abundant intrinsic oxygen defects at high temperatures, which drive the self-reduction of Mn⁴⁺ to Mn²⁺ and introduce a wide range of defect states within the wide bandgap. The discrete shallow trap levels enable efficient ML under external forces, while the high-concentration, quasi-continuous deep trap bands contribute to anomalous thermal quenching at elevated temperatures. This study demonstrates the feasibility of leveraging layered-tunnel structured materials with high defect tolerance to construct multifunctional luminescent materials via rational defect state engineering. It not only provides a direct solution to the conflicting demands of ML and thermal stability but also offers valuable insights for the development of advanced optical materials.

缺陷态在现代光学材料的发光性能中起着越来越重要的调节作用，它们的位置和分布直接决定了材料的发光行为。在发光材料中存在一个长期存在的挑战：弹性-机械发光（ML）材料依赖于浅阱水平，而具有高热稳定性的光致发光材料需要深阱水平。这些相互冲突的陷阱水平要求使得在单一材料中同时集成ML和优异的热稳定性非常困难。在这里，我们展示了一种通过层状隧道硅酸盐Sr2ZnSi2O7 （SZS）的解决方案，其宽带隙和独特的结构提供了出色的缺陷容忍度。当掺杂Mn2+时，Sr2ZnSi2O7:Mn2+ (SZSM)成功地集成了ML和异常热淬火性能。耐缺陷主体允许在高温下形成丰富的内禀氧缺陷，驱动Mn4+自还原为Mn2+，并在宽带隙内引入广泛的缺陷状态。在外力作用下，离散的浅层陷阱能级能够实现高效的ML，而高浓度、准连续的深层陷阱能带则会导致高温下的异常热猝灭。本研究论证了通过合理的缺陷状态工程，利用高缺陷容限的层状隧道结构材料构建多功能发光材料的可行性。它不仅为ML和热稳定性的冲突需求提供了直接解决方案，而且为先进光学材料的开发提供了宝贵的见解。

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引用次数: 0

Thermal characterization of buried interfaces in multilayer heterostructures via TDTR with periodic waveform analysis 基于周期波形分析的TDTR多层异质结构中埋藏界面热特性研究

IF 9.7 2区材料科学 Q1 MATERIALS SCIENCE, MULTIDISCIPLINARY

Materials Today Physics

Pub Date : 2026-01-01 Epub Date: 2025-12-13 DOI: 10.1016/j.mtphys.2025.101987

Mingzhen Zhang , Puqing Jiang , Ronggui Yang

Accurate evaluation of buried thermal interfaces is vital for understanding and optimizing heat dissipation in wide- and ultra-wide-bandgap (WBG/UWBG) semiconductor devices. Conventional time-domain thermoreflectance (TDTR) typically probes only near-surface transport due to its restricted modulation frequency range. Here, we employ a frequency-tunable periodic waveform analysis TDTR (PWA-TDTR) technique to perform depth-resolved thermal measurements on three representative systems: epitaxial ε-Ga₂O₃/SiC, GaN/Si, and mechanically bonded GaN/diamond. By combining broadband multi-frequency probing with sensitivity-guided joint fitting, we quantitively determine interfacial thermal conductance, layer-specific thermal conductivity, and volumetric heat capacity, without requiring destructive sample preparation. The results reveal that the buried Ga₂O₃/SiC interface exhibits weak phonon transmission due to acoustic mismatch; the transition layers in GaN/Si act as phonon-impedance gradients that redistribute heat flux; and the GaN/diamond boundary remains the dominant thermal bottleneck despite diamond's ultrahigh bulk conductivity. These findings demonstrate that the modulation frequency in PWA-TDTR functions as a tunable probe of depth-dependent phonon transport, directly linking frequency-domain thermal response to interfacial energy transmission. Overall, this work positions PWA-TDTR as a versatile platform for investigating buried nonmetal–nonmetal interfaces in next-generation high-power and optoelectronic materials.

准确评估埋藏热界面对于理解和优化宽和超宽带隙（WBG/UWBG）半导体器件的散热至关重要。传统的时域热反射（TDTR）由于其调制频率范围有限，通常只能探测近地表输运。在这里，我们采用频率可调周期波形分析TDTR （PWA-TDTR）技术对三个代表性体系：外延ε-Ga2O3/SiC、GaN/Si和机械键合GaN/金刚石进行深度分辨热测量。通过将宽带多频探测与灵敏度引导的接头拟合相结合，我们定量地确定了界面导热系数、层比导热系数和体积热容，而无需破坏性的样品制备。结果表明：埋置的Ga2O3/SiC界面由于声失配导致声子传输弱；GaN/Si中的过渡层作为声子阻抗梯度，重新分配热通量；尽管金刚石具有超高的体积导电性，但氮化镓/金刚石的边界仍然是主要的热瓶颈。这些发现表明，PWA-TDTR中的调制频率可以作为深度相关声子传输的可调探针，直接将频域热响应与界面能量传输联系起来。总的来说，这项工作将PWA-TDTR定位为研究下一代大功率光电材料中埋藏的非金属-非金属界面的多功能平台。

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引用次数: 0

Impact of channel thickness scaling on interface trap density and electrical properties of ultrathin oxide field-effect transistors 沟道厚度缩放对超薄氧化场效应晶体管界面阱密度和电学性能的影响

IF 9.7 2区材料科学 Q1 MATERIALS SCIENCE, MULTIDISCIPLINARY

Materials Today Physics

Pub Date : 2026-01-01 Epub Date: 2025-12-01 DOI: 10.1016/j.mtphys.2025.101968

Youngjin Kang , Taegyu Kim , Hyunhee Kim , San Nam , Hyunho Jang , Dongwon Kang , Jeong-Wan Jo , Sung Kyu Park , Yong-Hoon Kim

As oxide semiconductors are emerging as key materials for next-generation semiconductor devices, aggressive scaling requirements in technologies such as monolithic 3D integration necessitate a reduction in channel thickness. However, the electrical performance of oxide field-effect transistors (FETs) generally deteriorates markedly as the channel thickness decreases. To systematically investigate the effects of thickness scaling and the underlying mechanisms, indium-gallium-zinc-oxide (IGZO) and zinc-tin-oxide (ZTO) FETs were fabricated and their electrical characteristics were analyzed as a function of channel thickness. ZTO FETs exhibited a mobility of 37.8 cm²/V·s at a channel thickness of 5.1 nm, which decreased to 1.43 cm²/V·s at 2.7 nm, while consistently outperforming their IGZO counterparts across all thicknesses (cf. 5.3 nm: 10.19 cm²/V·s; 2.5 nm: 0.06 cm²/V·s). To further elucidate the degradation mechanism, activation energies associated with trap barrier heights were extracted from temperature-dependent mobility measurements. In addition, interface trap density (D_it) was quantified through capacitance-voltage and capacitance-frequency analyses using the conductance method. The results revealed a clear increase in D_it with decreasing channel thickness, with ZTO FETs exhibiting lower D_it values than IGZO FETs at comparable thicknesses, in strong correlation with their higher electrical performance.

随着氧化物半导体逐渐成为下一代半导体器件的关键材料，单片3D集成等技术对尺寸的要求越来越高，因此需要减小通道厚度。然而，随着沟道厚度的减小，氧化场效应晶体管（fet）的电性能通常会显著下降。为了系统地研究厚度缩放的影响及其机制，制备了氧化铟镓锌（IGZO）和氧化锌锡（ZTO）场效应管，并分析了它们的电学特性与沟道厚度的关系。在通道厚度为5.1 nm时，ZTO fet的迁移率为37.8 cm2/V·s，在2.7 nm时降至1.43 cm2/V·s，同时在所有厚度上都优于IGZO（比较：5.3 nm: 10.19 cm2/V·s; 2.5 nm: 0.06 cm2/V·s）。为了进一步阐明降解机制，从依赖温度的迁移率测量中提取了与陷阱势垒高度相关的活化能。此外，采用电导法通过电容-电压和电容-频率分析对界面陷阱密度（Dit）进行了量化。结果显示，Dit随沟道厚度的减小而明显增加，在相同厚度下，ZTO fet的Dit值低于IGZO fet，这与它们更高的电性能密切相关。

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引用次数: 0

Comprehensive insights into intrinsic thermal conduction mechanism of Sn-Bi-In alloys toward high-performance thermal interface materials: experimental and first-principles calculations Sn-Bi-In合金对高性能热界面材料的内在热传导机制的综合见解：实验和第一性原理计算

IF 9.7 2区材料科学 Q1 MATERIALS SCIENCE, MULTIDISCIPLINARY

Materials Today Physics

Pub Date : 2026-01-01 Epub Date: 2025-12-11 DOI: 10.1016/j.mtphys.2025.101978

Xuechi Wang , Xiaoliang Ji , Yishu Wang , Hao Yuan , Dan Li , Fu Guo

Miniaturized and high-power-density electronic devices present significant challenges for high-performance thermal interface materials (TIMs) that transfer heat energy more efficiently. Sn-Bi-In alloys, a promising class of metallic phase change TIMs, are notable for their low melting points and exceptional heat storage capacity during phase transition. However, the intrinsic thermal conduction mechanism of Sn-Bi-In alloys remains poorly understood, hindering efforts to improve their relatively low thermal conductivity. In this study, we designed and fabricated five Sn-Bi-In alloys with varying composition of Sn, Bi, and In, and systematically investigated the effects of phase composition, phase interfaces, and alloy microstructure on the thermal conductivity. It is found that 30 %Sn-30 %Bi–40 %In and eutectic 19 %Sn-22 %Bi–59 %In alloys (at.%) exhibit the highest thermal conductivity of ∼20 W m⁻¹ K⁻¹ due to the high thermal conductivity of internal InSn₄ and BiIn₂ phases, low-disregistry phase interface and high charge transfer across these phase interfaces according to first-principles calculations and atomic-scale characterization. In addition, microstructure refinement in Sn-Bi-In alloys by increasing solidification rate is not beneficial for the thermal conductivity; while the precipitation of low-thermal conductivity BiIn phase from pre-eutectic (Sn) solid solution during slow solidification negatively influences the thermal performance of high-Sn phase change alloys. The afore-determined intrinsic thermal conduction mechanism of Sn-Bi-In alloys can help provide a theoretical foundation and thus new pathway to developing higher-performance TIMs for thermal management in power electronics.

小型化和高功率密度的电子设备对高效传递热能的高性能热界面材料（TIMs）提出了重大挑战。Sn-Bi-In合金是一类很有前途的金属相变TIMs，具有较低的熔点和相变过程中优异的储热能力。然而，Sn-Bi-In合金的固有热传导机制仍然知之甚少，阻碍了改善其相对较低的导热性的努力。在本研究中，我们设计并制备了5种不同Sn、Bi和In组成的Sn-Bi-In合金，并系统地研究了相组成、相界面和合金显微组织对导热性能的影响。根据第一原理计算和原子尺度表征，发现30%Sn-30%Bi-40%In和共晶19%Sn-22%Bi-59%In合金（at.%）的热导率最高，为~ 20 W·m-1·K-1W，这是由于内部InSn4和BiIn2相的高热导率、低失配相界面和在这些相界面间的高电荷转移。此外，增加凝固速率对Sn-Bi-In合金的组织细化也不利于导热性能的提高；而在缓慢凝固过程中，从预共晶（Sn）固溶体中析出低导热BiIn相对高Sn相变合金的热性能有不利影响。上述Sn-Bi-In合金的固有热传导机制可以为开发用于电力电子热管理的高性能TIMs提供理论基础和新的途径。

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引用次数: 0