Materials Today Physics最新文献

{"title":"High-performance self-powered UV-to-NIR imaging photodetector based on Bi2Te3 p-n homojunction","authors":"Yinze Zhang ,&nbsp;Wen He ,&nbsp;Dongbo Wang ,&nbsp;Chenchen Zhao ,&nbsp;Yanghao Bi ,&nbsp;Xiangqian Fan ,&nbsp;Lei Chen ,&nbsp;Wei Wu ,&nbsp;Xuan Fang ,&nbsp;Gang Liu ,&nbsp;Liancheng Zhao ,&nbsp;Jinzhong Wang","doi":"10.1016/j.mtphys.2025.101779","DOIUrl":"10.1016/j.mtphys.2025.101779","url":null,"abstract":"<div><div>2D Bi₂Te₃ is an emerging semiconducting materials show considerable promise for application in the development of next-generation optoelectronic devices. Especially, broadband photodetection is crucial in various applications, including multispectral imaging and cognition. Therefore, tuning the physical properties of semiconductors and thereby building an efficient p-n homojunction are important for achieving a high-performance photodetection device. However, until now, it is still difficult to construct Bi₂Te₃ p-n homojunction. In this work, Sb-doped Bi₂Te₃ was synthesized via chemical vapor deposition, which exhibited typical p-type conduction behavior and a considerable hole mobility of 1.6 cm² V⁻¹ s⁻¹. Benefiting from the built-in electric field, the Bi₂Te₃ p-n homojunction displays an apparent rectification effect and an extremely low dark current of approximately 10⁻¹⁴ A. Under illumination, the p-n homojunction, serving as a photodiode, achieved a high power conversion efficiency of 4.65 % and an excellent responsivity of 802.9 A/W. Furthermore, taking advantage of the built-in electric field, the p-n homojunction exhibited broadband self-driving photodetection from 367 to 1550 nm with ultra-high detectivity (3.84 × 10¹³ Jones at 520 nm and 8.82 × 10¹¹ Jones at 1550 nm). This work provides an effective strategy for synthesizing p-type Bi₂Te₃ and emphasizes the pivotal role of homojunctions for high-performance broadband photodetectors.</div></div>","PeriodicalId":18253,"journal":{"name":"Materials Today Physics","volume":"56 ","pages":"Article 101779"},"PeriodicalIF":10.0,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144515578","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Rattling-induced effects of Ag atoms and anomalous phonon transport along with thermoelectric performance in silver-based chalcopyrite AgGaX2 (X = Se, Te)","authors":"Shuangshuang Luan ,&nbsp;Yinchang Zhao ,&nbsp;Jun Ni ,&nbsp;Zhenhong Dai","doi":"10.1016/j.mtphys.2025.101769","DOIUrl":"10.1016/j.mtphys.2025.101769","url":null,"abstract":"<div><div>A comprehensive elucidation of phonon transport mechanisms is imperative for the rational design of advanced thermoelectric materials exhibiting intrinsically low lattice thermal conductivity. In this work, the thermal and electrical transport behaviors of AgGaX<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span> (X = Se, Te) are comprehensively explored through self-consistent phonon calculations, compressive sensing techniques, and the Boltzmann transport equation. The ultralow lattice thermal conductivity (<span><math><msub><mrow><mi>κ</mi></mrow><mrow><mi>L</mi></mrow></msub></math></span>) of AgGaX<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span> is attributed to the strong anharmonicity due to the rattling modes of Ag atoms, strong phonon scattering due to the strong coupling between acoustic and low-frequency optical phonon branches, and the unusually high contribution of optical phonons to thermal conductivity. We also find that the <span><math><msub><mrow><mi>κ</mi></mrow><mrow><mi>L</mi></mrow></msub></math></span> of AgGaX<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span> (X = Se, Te) exhibits an anomalous trend compared to the conventional mass trend, with <span><math><msub><mrow><mi>κ</mi></mrow><mrow><mi>L</mi></mrow></msub></math></span> decreasing when the lighter Se atoms replace Te atoms. This anomalous phonon transport behavior is attributed to the weaker Ag–Se bonding strength, lower avoided crossing frequency, and the dominant contribution of optical phonons to <span><math><msub><mrow><mi>κ</mi></mrow><mrow><mi>L</mi></mrow></msub></math></span> (exceeding 60%) in AgGaSe<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>. The high band degeneracy and strong dispersion near the valence band maximum (VBM) result in a high power factor (<span><math><mrow><mi>P</mi><mi>F</mi></mrow></math></span>), which, combined with the ultralow <span><math><msub><mrow><mi>κ</mi></mrow><mrow><mi>L</mi></mrow></msub></math></span>, leads to excellent thermoelectric performance. Accounting for multiple scattering processes, the peak <span><math><mrow><mi>Z</mi><mi>T</mi></mrow></math></span> values of p-type AgGaSe<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span> and AgGaTe<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span> are predicted to attain 2.53 and 2.71 at 700 K, respectively. The inclusion of spin–orbit coupling (SOC) causes the peak <span><math><mrow><mi>Z</mi><mi>T</mi></mrow></math></span> values to decrease to 1.99 and 2.14, representing decreases of 22.1% and 21%, respectively. These results indicate that AgGaX<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span> is a promising class of high performance thermoelectric materials, and its unique phonon dynamics and electron transport properties make it promising for thermoelectric applications.</div></div>","PeriodicalId":18253,"journal":{"name":"Materials Today Physics","volume":"56 ","pages":"Article 101769"},"PeriodicalIF":10.0,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144515437","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"High figure-of-merit of Mg1.96Zn0.04(Si0.3Sn0.7)0.98Sb0.02 alloy through simultaneous optimization of electrical and thermal transports","authors":"Pritam Sarkar, Pankaj Gupta, U. Sandhya Shenoy, Surjeet Singh, Sayandeep Kundu, Nitin Kumawat, Dinesh Kedia, D. Krishna Bhat, Shovit Bhattacharya, Ajay Singh","doi":"10.1016/j.mtphys.2025.101776","DOIUrl":"https://doi.org/10.1016/j.mtphys.2025.101776","url":null,"abstract":"The derivatives of Mg<ce:inf loc=\"post\">2</ce:inf>Si have recently attracted wide attention as promising thermoelectric materials due to earth abundant and environment friendly low-cost constituents. The main challenge in optimizing the thermoelectric figure of merit <ce:italic>ZT</ce:italic>, is the low electrical and high thermal conductivities of Mg<ce:inf loc=\"post\">2</ce:inf>Si. The present study demonstrates high <ce:italic>ZT</ce:italic> of ∼ 1.6 at 673 K in Mg<ce:inf loc=\"post\">2</ce:inf>Si<ce:inf loc=\"post\">0.3</ce:inf>Sn<ce:inf loc=\"post\">0.7</ce:inf> through simultaneous optimization of electrical and thermal transport through Sb and Zn co-doping<ce:inf loc=\"post\">.</ce:inf> The ultra-low deformation and alloy scattering potentials in Sb and Zn co-doped samples helps in maintaining record high Hall mobility ∼ 70-90 cm<ce:sup loc=\"post\">2</ce:sup>/V.s. The doping induced pudding mold band structure with hyperconvergence in conduction band balances high Seebeck coefficient and high electrical conductivity. The point defects and dislocations created by doping helps in lowering of lattice thermal conductivity as well. The uni-leg power generator fabricated using optimized Mg<ce:inf loc=\"post\">1.96</ce:inf>Zn<ce:inf loc=\"post\">0.04</ce:inf>(Si<ce:inf loc=\"post\">0.3</ce:inf>Sn<ce:inf loc=\"post\">0.7</ce:inf>)<ce:inf loc=\"post\">0.98</ce:inf>Sb<ce:inf loc=\"post\">0.02</ce:inf> exhibits a record efficiency of ∼ 9.5 % at Δ<ce:italic>T</ce:italic> ∼ 329 K.","PeriodicalId":18253,"journal":{"name":"Materials Today Physics","volume":"36 1","pages":""},"PeriodicalIF":11.5,"publicationDate":"2025-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144515438","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Accurate prediction of band gap of two-dimensional monolayer materials via transfer learning","authors":"Jingfeng Wang ,&nbsp;Zihe Li ,&nbsp;Mengke Li ,&nbsp;Wenyan Jiao ,&nbsp;Yufeng Luo ,&nbsp;Huijun Liu ,&nbsp;Ying Fang","doi":"10.1016/j.mtphys.2025.101774","DOIUrl":"10.1016/j.mtphys.2025.101774","url":null,"abstract":"<div><div>Band gap is a crucial factor for the design and discovery of novel functional materials with desired properties. In principle, the band gap can be accurately predicted by using first-principles calculations with quasiparticle self-energy corrections, which is however very time-consuming and thus limited to small systems. In this work, using a pre-trained neural network architecture for the band gap calculated with standard Perdew-Burke-Ernzerhof (PBE) functional, we propose a transfer learning (TL) model to readily and accurately predict the band gap of any monolayer materials, where a small set of GW-calculated gaps is used as training data. Compared with general machine learning algorithms, the TL-driven model shows superior predictive performance, as manifested by improved Pearson correlation coefficient (reduced mean absolute error) from 71 % to 97 % (0.55–0.27) between the real and predicted band gaps. Importantly, the established TL model with good interpretability is leveraged to predict the GW gaps of 2915 monolayer systems that are retrieved from the Computational 2D Materials Database (C2DB) with non-zero PBE gaps, providing a rich sample space for exploring high performance functional materials with suitable band gap.</div></div>","PeriodicalId":18253,"journal":{"name":"Materials Today Physics","volume":"56 ","pages":"Article 101774"},"PeriodicalIF":10.0,"publicationDate":"2025-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144340927","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Constructing 3D g-CNNS network in epoxy for enhanced thermal conductivity and breakdown strength for high high-voltage applications","authors":"Chenyu Su ,&nbsp;Guozheng Cao ,&nbsp;Xiaolong Chen ,&nbsp;Jiahuan Zhao ,&nbsp;Fanrong Kong ,&nbsp;Jing Liu ,&nbsp;Wenying Zhou","doi":"10.1016/j.mtphys.2025.101773","DOIUrl":"10.1016/j.mtphys.2025.101773","url":null,"abstract":"<div><div>Ultra-high integration density of power electronics leads to severely localized heat accumulation, critically threatening the safe operation and lifetime of devices. Traditional high thermal conductivity (TC) polymer composites always suffer from deteriorated breakdown strength (<em>E</em>_b). Nowadays, effective decoupling regulation and synchronous enhancement of TC and <em>E</em>_b still is a formidable challenge in polymer composites. To tackle this problematic issue, in this work, the graphitic carbon nitride nanosheet (g-CNNS) was prepared using a thermal oxidation method, and the g-CNNS/cellulose nanofiber (CNF)/epoxy (EP) nanocomposites were prepared via ice-templating and infiltration methods. It is found that the uniformly distributed three-dimensional CNF supporting g-CNNS skeletons were constructed in EP even at low filler loadings. The CNFs can physically crosslink with EP groups and form hydrogen bonds with g-CNNS, not only enhancing the interfacial interactions but also restricting the EP chain mobility, subsequently leading to concurrently improved TC and <em>E</em>_b in g-CNNS/CNF/EP. The 10.4 wt% g-CNNS/CNF/EP exhibits a concurrently high TC and <em>E</em>_b of 1.06 W/(m·K) and 34.7 kV/mm, along with a low permittivity (<em>ε</em>) and dielectric loss (tan<em>δ</em>) of 2.47 and 0.022 at 10³ Hz, respectively. This work reveals the underlying heat conduction and charge migration mechanisms, provides deep insight into the design and preparation of EP nanomaterials with simultaneously high TC and <em>E</em>_b coupled with low <em>ε</em> and tan<em>δ</em>, presenting appealing applications in power systems and high frequency microelectronic devices.</div></div>","PeriodicalId":18253,"journal":{"name":"Materials Today Physics","volume":"56 ","pages":"Article 101773"},"PeriodicalIF":10.0,"publicationDate":"2025-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144371053","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Solvent-engineered NiMo-based electrocatalysts for simultaneous hydrogen evolution and PET plastic waste upcycling","authors":"Yang Yang ,&nbsp;Mingkun Jiang ,&nbsp;Yajie Wang,&nbsp;Yanyang Zhang,&nbsp;Yizhi Wu,&nbsp;Dan Wu","doi":"10.1016/j.mtphys.2025.101775","DOIUrl":"10.1016/j.mtphys.2025.101775","url":null,"abstract":"<div><div>The massive accumulation of polyethylene terephthalate (PET) plastic waste urgently requires sustainable resource recovery strategies. Conventional PET recycling struggles with efficiently valorizing ethylene glycol (EG), a major depolymerization byproduct, limiting economic viability and material circularity. This study designs NiMo bifunctional electrocatalysts via a solvent-modulated strategy to synergistically drive hydrogen evolution (HER) and EG oxidation (EGOR) for integrated plastic upcycling and green H₂ production. By adjusting water/EG ratios, precise control over phase composition and nanostructure evolution is achieved, governed by solvent-polarity-dependent dynamic reconstruction. Water-rich synthesis yields NiMo-W₃₀ nanorods with optimized hydrogen adsorption kinetics, delivering exceptional HER activity (η₁₀ = 8.21 mV, Tafel slope = 36.5 mV dec⁻¹). Conversely, EG-dominated synthesis produces ultrathin NiMo-W_0.5EG_29.5 nanosheets, where in situ Mo leaching generates Ni³⁺-rich active sites, achieving 93 % selectivity for formic acid via selective EGOR. A membrane electrolyzer integrating these catalysts concurrently upgrades 10 g PET into 8.43 g terephthalic acid and 7.76 g potassium diformate while generating 94.86 mmol H₂ at 1.58 V, surpassing conventional water splitting by 208 mV. Techno-economic analysis confirms a net profit of $244 per ton of PET treated, contrasting sharply with the $261 loss of traditional water electrolysis. This work establishes a closed-loop paradigm for plastic valorization and sustainable catalyst design.</div></div>","PeriodicalId":18253,"journal":{"name":"Materials Today Physics","volume":"56 ","pages":"Article 101775"},"PeriodicalIF":10.0,"publicationDate":"2025-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144371042","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Subgroup discovery similarity score (SDSS): A significant criterion for the integration of statistical knowledge into machine learning in materials science","authors":"Huiran Zhang ,&nbsp;Mengmeng Dai ,&nbsp;Yudian Lin ,&nbsp;Baoyu Xu ,&nbsp;Pin Wu ,&nbsp;Lei Huang ,&nbsp;Huanyu Xu ,&nbsp;Shengzhou Li ,&nbsp;Yan Xu ,&nbsp;Zheng Tang ,&nbsp;Jincang Zhang ,&nbsp;Renchao Che ,&nbsp;Tao Xu ,&nbsp;Dongbo Dai","doi":"10.1016/j.mtphys.2025.101772","DOIUrl":"10.1016/j.mtphys.2025.101772","url":null,"abstract":"<div><div>In materials science research, knowledge and machine learning (ML) have a mutually reinforcing relationship. In efforts to improve the ability of learning material datasets, researchers obtain statistical knowledge from ML models and integrate it into subsequent ML models in different ways. However, determining the most suitable method for integrating statistical knowledge into the next stage remains challenging. This limits the precise application of knowledge-driven approaches. In this work, the Subgroup Discovery Similarity Score (SDSS) is proposed as a key criterion for integrating statistical knowledge into ML models. Statistical knowledge is extracted from material datasets by subgroup discovery. In the solid solution strengthening (<span><math><mrow><msub><mrow><mo>Δ</mo><mi>H</mi></mrow><mrow><mi>S</mi><mi>S</mi><mi>S</mi></mrow></msub></mrow></math></span>) dataset, a divide-and-conquer strategy achieves a correlation coefficient of 0.96 and a MAPE of 18.44 %, and reveals distinct strengthening mechanisms for the face-centered cubic (FCC) and body-centered cubic (BCC) phases. In the piezoelectric coefficients (<span><math><mrow><msub><mi>d</mi><mn>33</mn></msub></mrow></math></span>) dataset, statistical knowledge is encoded as features and embedded into the ML model for feature enhancement, effectively reducing the prediction error. The results suggest that our framework can extract and integrate statistical knowledge from material datasets into ML models without prior domain knowledge.</div></div>","PeriodicalId":18253,"journal":{"name":"Materials Today Physics","volume":"56 ","pages":"Article 101772"},"PeriodicalIF":10.0,"publicationDate":"2025-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144335397","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Antisite defect “conductivity barrier” and 5d orbital hybridization for enhanced resistivity in piezoelectric crystals","authors":"Linyu Bai ,&nbsp;Dongjie Liu ,&nbsp;Qingzhi Song ,&nbsp;Qingshan Bao ,&nbsp;Xi Gao ,&nbsp;Xian Zhao ,&nbsp;Fapeng Yu ,&nbsp;Yanlu Li ,&nbsp;Shujun Zhang","doi":"10.1016/j.mtphys.2025.101771","DOIUrl":"10.1016/j.mtphys.2025.101771","url":null,"abstract":"<div><div>Piezoelectric crystals are extensively employed in sensing technologies, yet their intrinsic low resistivity at elevated temperatures poses a critical challenge, significantly hindering their application in high-temperature environments. It is found that Ta-containing piezoelectric crystals possess higher resistivity than their Nb-containing counterparts, but the underlying mechanisms remain unclear. Herein, we propose a novel electron relaxation mechanism that highlights the 5<em>d</em> orbital hybridization induced efficient electron trapping in antisite defects through a comparative analysis of La₃Ga_5.5Ta_0.5O₁₄ (LGT) and La₃Ga_5.5Nb_0.5O₁₄ (LGN) crystals. Our study reveals that the spatial extension of Ta-5<em>d</em> orbitals strengthens hybridization with O-2<em>p</em> orbitals, significantly increasing the crystal field splitting energy and deepening the Ta_Ga polaron potential well, which collectively elevate the excitation energy for electron release, accelerate the carrier recombination, and ultimately suppress electrical conductivity while boosting resistivity. Leveraging this mechanism, LGT crystal features a remarkable three-orders-of-magnitude enhancement in resistivity by co-regulation of electron concentration, antisite defect density and occupation sites via combining oxygen atmospheric control and Al doping. This study provides a new insight into the conduction mechanism and a general Ta-based design strategy for resistivity modulation beyond the piezoelectric crystals.</div></div>","PeriodicalId":18253,"journal":{"name":"Materials Today Physics","volume":"56 ","pages":"Article 101771"},"PeriodicalIF":10.0,"publicationDate":"2025-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144329268","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Large-area high-yield 1T-TiSe2 saturable absorber for wavelength-tunable ultrafast fiber lasers","authors":"Zixin Yang ,&nbsp;Jian Wu ,&nbsp;Qiang Yu ,&nbsp;Xingang Hou ,&nbsp;Zhiyuan Zhang ,&nbsp;Xiaobin Wang ,&nbsp;Jinhai Zou ,&nbsp;Zhongquan Nie ,&nbsp;Jinyong Leng ,&nbsp;Pu Zhou ,&nbsp;Zongfu Jiang","doi":"10.1016/j.mtphys.2025.101770","DOIUrl":"10.1016/j.mtphys.2025.101770","url":null,"abstract":"<div><div>The production of high-yield saturable absorbers (SAs) with broad effective modulation zones remains a considerable challenge for the advancement of compact ultrafast fiber lasers. We present a fiber-end-integrated large-area high-yield 1T-TiSe₂ saturable absorber fabricated using chemical vapor transport (CVT) and accurate transfer technique. This strategic method achieves a three-order-of-magnitude enhancement in device area (tens of micrometers) compared to conventional liquid-phase exfoliation approaches. The comprehensive 1T-TiSe₂ has exceptional nonlinear optical properties, with a modulation depth of 20.1(±0.3)% and a saturation intensity of 7.29(±0.2) μJ/cm². The erbium-doped fiber laser enables the generation of stable femtosecond pulses with a compressed duration of 966 fs at a frequency of 13.84 MHz, marking a significant improvement over previously recorded picosecond durations. Additionally, a wavelength-tunable Q-switched laser has been demonstrated, including an 18 nm spectral range and maximum single-pulse energy of 62.4 nJ at 1565.8 nm. The findings highlight the exceptional potential of large-area 1T-TiSe₂ in integrating compact fiber laser design with high-energy ultrafast photonics, therefore establishing a versatile platform for tunable, high-performance pulsed laser systems.</div></div>","PeriodicalId":18253,"journal":{"name":"Materials Today Physics","volume":"56 ","pages":"Article 101770"},"PeriodicalIF":10.0,"publicationDate":"2025-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144296267","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Revealing electrical and mechanical degradation of Ni/Bi2Te3 interface through the quantitative interfacial diffusion analysis","authors":"Tian Qiu ,&nbsp;Zhi Li ,&nbsp;Jie Zhou ,&nbsp;Man Zhou ,&nbsp;Shucheng Bao ,&nbsp;Wei Zhu ,&nbsp;Yuan Deng","doi":"10.1016/j.mtphys.2025.101768","DOIUrl":"10.1016/j.mtphys.2025.101768","url":null,"abstract":"<div><div>Bismuth telluride (Bi₂Te₃)-based thermoelectric devices exhibit significant potential for energy harvesting and thermal management. However, device reliability and further development are critically limited by interface-induced failures, largely because quantitative failure analysis methods are lacking. This study systematically investigates interfacial degradation mechanisms and establishes a method for device lifetime prediction. First, accelerated thermal stress experiments are designed to analyze the Ni diffusion behavior at interface of different-type Bi₂Te₃-based TE materials, thereby determining the quantitative relationship among temperature (<em>T</em>), duration (<em>t</em>), activation energy (Δ<em>E</em>) and diffusion coefficient (<em>D</em>). Besides, the Ni diffusion depth (<span><math><mrow><mi>x</mi></mrow></math></span>) is confirmed to scale linearly with the square root of time (<span><math><mrow><mi>x</mi><mo>∝</mo><msup><mi>t</mi><mrow><mn>1</mn><mo>/</mo><mn>2</mn></mrow></msup></mrow></math></span>) for a given diffusion coefficient, which is consistent with Fick's second law (<span><math><mrow><mi>D</mi><mo>=</mo><msup><mi>x</mi><mn>2</mn></msup><mo>/</mo><mn>4</mn><mi>t</mi></mrow></math></span>). Moreover, both interfacial specific contact resistivity (<span><math><mrow><msub><mi>ρ</mi><mi>c</mi></msub></mrow></math></span>) and tensile strength (<span><math><mrow><msub><mi>σ</mi><mi>s</mi></msub></mrow></math></span>) exhibit linear correlations with Ni diffusion depth under a specific degradation mechanism, enabling quantitative assessment of interface stability. Ultimately, adopting standard resistance failure criteria, we completely propose a method for quantitative lifetime prediction, which might provide universal applicability for the reliability assessment of thermoelectric devices and advance the prediction method of interface-induced failure analysis.</div></div>","PeriodicalId":18253,"journal":{"name":"Materials Today Physics","volume":"56 ","pages":"Article 101768"},"PeriodicalIF":10.0,"publicationDate":"2025-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144260499","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}