Pub Date : 2025-12-11DOI: 10.1016/j.mtphys.2025.101985
Yoonjae Lee , Dong-min Kim , Joon Sang Kang
The thermoelectric properties of bismuth–antimony (BiSb) single crystals under magnetic fields have recently attracted considerable attention owing to their tunability through external magnetic modulation. However, previous studies have largely focused on specific Sb concentrations and limited transport geometries, leaving the broader potential of magnetic control largely unexplored. Here, we present a comprehensive and systematic investigation of the thermoelectric properties of BiSb single crystals under magnetic fields ranging from −1.5 T to 1.5 T and temperatures between 80 K and 300 K, as a function of Sb concentration and crystal orientation. Remarkably, we observe pronounced anisotropy and substantial enhancement of thermoelectric performance, achieving a figure of merit of zT ≈ 0.4 along the (010) axis and an exceptional zT ≈ 1.4 along the (001) axis under magnetic field 0.5 T at 160 K. These results provide the clear experimental demonstration that both magnetic fields and crystallographic orientation can serve as powerful tools to dynamically tune thermoelectric efficiency.
铋锑（BiSb - antimony, BiSb）单晶在磁场作用下的热电特性由于其可通过外磁调制而得到广泛关注。然而，先前的研究主要集中在特定的Sb浓度和有限的输运几何形状上，使得磁控制的更广泛潜力在很大程度上未被探索。本文全面系统地研究了铋单晶在-1.5 T ~ 1.5 T磁场和80 K ~ 300 K温度下的热电特性，以及铋浓度和晶体取向的函数关系。值得注意的是，我们观察到明显的各向异性和热电性能的显著增强，在160 K的0.5 T磁场下，沿（010）轴的优值zT≈0.4，沿（001）轴的优值zT≈1.4。这些结果提供了清晰的实验证明，磁场和晶体取向都可以作为动态调节热电效率的有力工具。
{"title":"Magnetic-fields-driven giant and anisotropic thermoelectric enhancement in BiSb crystals","authors":"Yoonjae Lee , Dong-min Kim , Joon Sang Kang","doi":"10.1016/j.mtphys.2025.101985","DOIUrl":"10.1016/j.mtphys.2025.101985","url":null,"abstract":"<div><div>The thermoelectric properties of bismuth–antimony (BiSb) single crystals under magnetic fields have recently attracted considerable attention owing to their tunability through external magnetic modulation. However, previous studies have largely focused on specific Sb concentrations and limited transport geometries, leaving the broader potential of magnetic control largely unexplored. Here, we present a comprehensive and systematic investigation of the thermoelectric properties of BiSb single crystals under magnetic fields ranging from −1.5 T to 1.5 T and temperatures between 80 K and 300 K, as a function of Sb concentration and crystal orientation. Remarkably, we observe pronounced anisotropy and substantial enhancement of thermoelectric performance, achieving a figure of merit of zT ≈ 0.4 along the (010) axis and an exceptional zT ≈ 1.4 along the (001) axis under magnetic field 0.5 T at 160 K. These results provide the clear experimental demonstration that both magnetic fields and crystallographic orientation can serve as powerful tools to dynamically tune thermoelectric efficiency.</div></div>","PeriodicalId":18253,"journal":{"name":"Materials Today Physics","volume":"60 ","pages":"Article 101985"},"PeriodicalIF":9.7,"publicationDate":"2025-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145717942","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}
Pub Date : 2025-12-11DOI: 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.
{"title":"Comprehensive insights into intrinsic thermal conduction mechanism of Sn-Bi-In alloys toward high-performance thermal interface materials: experimental and first-principles calculations","authors":"Xuechi Wang , Xiaoliang Ji , Yishu Wang , Hao Yuan , Dan Li , Fu Guo","doi":"10.1016/j.mtphys.2025.101978","DOIUrl":"10.1016/j.mtphys.2025.101978","url":null,"abstract":"<div><div>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<sup>−1</sup> K<sup>−1</sup> due to the high thermal conductivity of internal InSn<sub>4</sub> and BiIn<sub>2</sub> 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.</div></div>","PeriodicalId":18253,"journal":{"name":"Materials Today Physics","volume":"60 ","pages":"Article 101978"},"PeriodicalIF":9.7,"publicationDate":"2025-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145718340","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}
Pub Date : 2025-12-10DOI: 10.1016/j.mtphys.2025.101984
Yuan-Fong Chou Chau
Plasmonic nanomaterials have emerged as transformative tools in environmental monitoring, enabling ultrasensitive detection of pollutants, toxins, and greenhouse gases through localized surface plasmon resonance (LSPR), surface-enhanced Raman scattering (SERS), and plasmon-enhanced photocatalysis. This review comprehensively examines the recent progress in plasmonic-based environmental sensing and pollution control, emphasizing mechanisms, material innovations, and integrated system designs. We discuss the fundamental plasmonic principles governing light–matter interactions at the nanoscale and highlight advances in noble metal and hybrid nanostructures for the detection of heavy metals, volatile organic compounds, and micro/nanoplastics in air and water. Special attention is devoted to plasmonic-assisted photocatalytic degradation and photothermal detoxification pathways for sustainable remediation. Emerging trends, including low-cost fabrication, machine learning–assisted data analytics, and coupling with renewable energy platforms, are explored as enablers for real-time field-deployable monitoring systems. Finally, challenges related to scalability, selectivity, and environmental safety are addressed, and future directions are outlined for developing smart, sustainable plasmonic technologies that bridge nanoscale optics with global environmental resilience.
{"title":"Plasmonics in environmental sensing, pollution monitoring, and sustainable applications","authors":"Yuan-Fong Chou Chau","doi":"10.1016/j.mtphys.2025.101984","DOIUrl":"10.1016/j.mtphys.2025.101984","url":null,"abstract":"<div><div>Plasmonic nanomaterials have emerged as transformative tools in environmental monitoring, enabling ultrasensitive detection of pollutants, toxins, and greenhouse gases through localized surface plasmon resonance (LSPR), surface-enhanced Raman scattering (SERS), and plasmon-enhanced photocatalysis. This review comprehensively examines the recent progress in plasmonic-based environmental sensing and pollution control, emphasizing mechanisms, material innovations, and integrated system designs. We discuss the fundamental plasmonic principles governing light–matter interactions at the nanoscale and highlight advances in noble metal and hybrid nanostructures for the detection of heavy metals, volatile organic compounds, and micro/nanoplastics in air and water. Special attention is devoted to plasmonic-assisted photocatalytic degradation and photothermal detoxification pathways for sustainable remediation. Emerging trends, including low-cost fabrication, machine learning–assisted data analytics, and coupling with renewable energy platforms, are explored as enablers for real-time field-deployable monitoring systems. Finally, challenges related to scalability, selectivity, and environmental safety are addressed, and future directions are outlined for developing smart, sustainable plasmonic technologies that bridge nanoscale optics with global environmental resilience.</div></div>","PeriodicalId":18253,"journal":{"name":"Materials Today Physics","volume":"60 ","pages":"Article 101984"},"PeriodicalIF":9.7,"publicationDate":"2025-12-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145711405","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}
Pub Date : 2025-12-09DOI: 10.1016/j.mtphys.2025.101980
Siying Gao , Lei Ge , Zixu Sa , Guangcan Wang , Pengsheng Li , Yan Peng , Mingsheng Xu , Zai-xing Yang
The inevitable crystalline defects and bandgap structure are challenging diamond in the coming electronics and optoelectronics. In this work, the type-II heterojunction of diamond is demonstrated to be transformed from the easy construction of type-I heterojunction by assistance of crystalline defects, benefiting to smart self-powered broadband photodetector. The as-fabricated photodetector exhibits excellent self-powered broadband photodetection behaviors, including low dark current of 4.54 × 10−14 A, high photocurrent-to-dark-current ratio of 4.41 × 104, and fast response times of 2.7/1.9 ms. The excellent photodetection performance further enables diamond in the undersea photodetection and imaging. This work paves the way of defect-riched diamond for high-performance self-powered broadband photodetection.
{"title":"Defect-assisted smart self-powered broadband photodetection of diamond for undersea imaging","authors":"Siying Gao , Lei Ge , Zixu Sa , Guangcan Wang , Pengsheng Li , Yan Peng , Mingsheng Xu , Zai-xing Yang","doi":"10.1016/j.mtphys.2025.101980","DOIUrl":"10.1016/j.mtphys.2025.101980","url":null,"abstract":"<div><div>The inevitable crystalline defects and bandgap structure are challenging diamond in the coming electronics and optoelectronics. In this work, the type-II heterojunction of diamond is demonstrated to be transformed from the easy construction of type-I heterojunction by assistance of crystalline defects, benefiting to smart self-powered broadband photodetector. The as-fabricated photodetector exhibits excellent self-powered broadband photodetection behaviors, including low dark current of 4.54 × 10<sup>−14</sup> A, high photocurrent-to-dark-current ratio of 4.41 × 10<sup>4</sup>, and fast response times of 2.7/1.9 ms. The excellent photodetection performance further enables diamond in the undersea photodetection and imaging. This work paves the way of defect-riched diamond for high-performance self-powered broadband photodetection.</div></div>","PeriodicalId":18253,"journal":{"name":"Materials Today Physics","volume":"60 ","pages":"Article 101980"},"PeriodicalIF":9.7,"publicationDate":"2025-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145705023","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}
Pub Date : 2025-12-09DOI: 10.1016/j.mtphys.2025.101981
Min Seop Kim , Chan Wook Jang , Won Uk Jeong , Sung Kim , R.G. Elliman , Euyheon Hwang , Jong Seok Lee , Suk-Ho Choi
Topological semimetals (TSMs), which host massless Dirac fermions, offer a promising platform to explore quantum phenomena. Topological Lifshitz transitions (LTs) are ubiquitous, with applications spanning ferromagnetism, superconductors, topological materials, and even high-energy physics. In this study, we observe a topological LT in epitaxial thin films of Bi0.96Sb0.04 without external excitations, where the TSM characteristics are retained throughout the transition. The LT is revealed by a thickness-dependent shift in plasma frequency, measured through terahertz (THz) optical conductivity spectroscopy. Only in ultrathin two-dimensional (2D) films (thickness ≤10 nm) does the emitted THz wave show a clear difference between left- and right-circularly polarized light, a circular photogalvanic effect that is a hallmark of Weyl semimetals. Such behavior signals a topological phase transition caused by inversion symmetry breaking in films with thickness ≤10 nm, thereby providing experimental confirmation of the LT in TSMs. The optical conductivity shows a similar critical change at a thickness of 10 nm, which matches the thickness-dependent trend in electrical conductivity measured in simple planar devices. Finally, a strong correlation is observed between the plasma frequency and carrier density in this 2D regime, consistent with prior theoretical predictions.
{"title":"Experimental manifestation of topological lifshitz transition by observing thickness-dependent shift of plasma frequency in topological semimetals","authors":"Min Seop Kim , Chan Wook Jang , Won Uk Jeong , Sung Kim , R.G. Elliman , Euyheon Hwang , Jong Seok Lee , Suk-Ho Choi","doi":"10.1016/j.mtphys.2025.101981","DOIUrl":"10.1016/j.mtphys.2025.101981","url":null,"abstract":"<div><div>Topological semimetals (TSMs), which host massless Dirac fermions, offer a promising platform to explore quantum phenomena. Topological Lifshitz transitions (LTs) are ubiquitous, with applications spanning ferromagnetism, superconductors, topological materials, and even high-energy physics. In this study, we observe a topological LT in epitaxial thin films of Bi<sub>0</sub>.<sub>96</sub>Sb<sub>0</sub>.<sub>04</sub> without external excitations, where the TSM characteristics are retained throughout the transition. The LT is revealed by a thickness-dependent shift in plasma frequency, measured through terahertz (THz) optical conductivity spectroscopy. Only in ultrathin two-dimensional (2D) films (thickness ≤10 nm) does the emitted THz wave show a clear difference between left- and right-circularly polarized light, a circular photogalvanic effect that is a hallmark of Weyl semimetals. Such behavior signals a topological phase transition caused by inversion symmetry breaking in films with thickness ≤10 nm, thereby providing experimental confirmation of the LT in TSMs. The optical conductivity shows a similar critical change at a thickness of 10 nm, which matches the thickness-dependent trend in electrical conductivity measured in simple planar devices. Finally, a strong correlation is observed between the plasma frequency and carrier density in this 2D regime, consistent with prior theoretical predictions.</div></div>","PeriodicalId":18253,"journal":{"name":"Materials Today Physics","volume":"60 ","pages":"Article 101981"},"PeriodicalIF":9.7,"publicationDate":"2025-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145704491","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}
Pub Date : 2025-12-08DOI: 10.1016/j.mtphys.2025.101982
Qin Ye , Changmin Shi , Hongjie Yan , Meijie Chen
Cooling is essential for electronic devices, ensuring their safe and stable operation, especially under sunlight due to solar heating at high ambient temperatures. Traditional cooling strategies, such as air-conditioners, forced convection with air and water, require the use of extensive power and additional instruments. Recent breakthroughs in materials and structural design for passive cooling, particularly in areas such as sky radiative cooling and evaporative cooling, are paving the way for advanced thermal management solutions to address the rapidly growing energy demand associated with electronics. In this review, we categorize passive cooling strategies into four main types: thermal conduction, thermal convection, thermal radiation, and latent heat. Representative approaches, including novel thermoregulation materials, optimized structures for natural convection, radiative cooling, and evaporative cooling designs, are highlighted. We examine the evaluation criteria and application scenarios for each strategy and provide a comprehensive discussion of their respective challenges and opportunities. Our analysis emphasizes the limitations of single-mode approaches and highlights the potential of hybrid passive cooling systems to enhance overall performance and reliability.
{"title":"Passive cooling strategies for outdoor electronic devices and beyond","authors":"Qin Ye , Changmin Shi , Hongjie Yan , Meijie Chen","doi":"10.1016/j.mtphys.2025.101982","DOIUrl":"10.1016/j.mtphys.2025.101982","url":null,"abstract":"<div><div>Cooling is essential for electronic devices, ensuring their safe and stable operation, especially under sunlight due to solar heating at high ambient temperatures. Traditional cooling strategies, such as air-conditioners, forced convection with air and water, require the use of extensive power and additional instruments. Recent breakthroughs in materials and structural design for passive cooling, particularly in areas such as sky radiative cooling and evaporative cooling, are paving the way for advanced thermal management solutions to address the rapidly growing energy demand associated with electronics. In this review, we categorize passive cooling strategies into four main types: thermal conduction, thermal convection, thermal radiation, and latent heat. Representative approaches, including novel thermoregulation materials, optimized structures for natural convection, radiative cooling, and evaporative cooling designs, are highlighted. We examine the evaluation criteria and application scenarios for each strategy and provide a comprehensive discussion of their respective challenges and opportunities. Our analysis emphasizes the limitations of single-mode approaches and highlights the potential of hybrid passive cooling systems to enhance overall performance and reliability.</div></div>","PeriodicalId":18253,"journal":{"name":"Materials Today Physics","volume":"60 ","pages":"Article 101982"},"PeriodicalIF":9.7,"publicationDate":"2025-12-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145696975","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}
Pub Date : 2025-12-06DOI: 10.1016/j.mtphys.2025.101972
Lu-Cheng Hou , Shih-Yao Chien , Chien-Neng Liao
Dispenser-printed thick-film thermoelectric modules (TF-TEMs) are an appealing option for energy harvesting and active heat dissipation applications due to their ease of processing and low material consumption. In this study, a flexible TF-TEM comprising six pairs of 300 μm-thick Bi2Te3-based legs was fabricated on a polyimide substrate via dispenser printing and a single-step sintering/bonding process. A selectively plated Ni/Pd barrier metallization was introduced to suppress interfacial reactions between the printed legs and Cu pads for improved structural integrity. The device delivered a maximum output power of ∼350 μW at ΔT = 32 K and a coefficient of performance of 3.2 at a heat pumping capacity of 26 mW/cm2. Furthermore, stable electrical resistance was maintained for the TF-TEM after 500 cycles of bending at a radius of 30 mm. This study demonstrates a feasible route toward monolithic integration of TF-TEMs for power generation of wearable devices and heat dissipation of microsystems.
{"title":"Energy harvesting and active heat dissipation of dispenser-printed thick-film thermoelectric modules","authors":"Lu-Cheng Hou , Shih-Yao Chien , Chien-Neng Liao","doi":"10.1016/j.mtphys.2025.101972","DOIUrl":"10.1016/j.mtphys.2025.101972","url":null,"abstract":"<div><div>Dispenser-printed thick-film thermoelectric modules (TF-TEMs) are an appealing option for energy harvesting and active heat dissipation applications due to their ease of processing and low material consumption. In this study, a flexible TF-TEM comprising six pairs of 300 μm-thick Bi<sub>2</sub>Te<sub>3</sub>-based legs was fabricated on a polyimide substrate via dispenser printing and a single-step sintering/bonding process. A selectively plated Ni/Pd barrier metallization was introduced to suppress interfacial reactions between the printed legs and Cu pads for improved structural integrity. The device delivered a maximum output power of ∼350 μW at ΔT = 32 K and a coefficient of performance of 3.2 at a heat pumping capacity of 26 mW/cm<sup>2</sup>. Furthermore, stable electrical resistance was maintained for the TF-TEM after 500 cycles of bending at a radius of 30 mm. This study demonstrates a feasible route toward monolithic integration of TF-TEMs for power generation of wearable devices and heat dissipation of microsystems.</div></div>","PeriodicalId":18253,"journal":{"name":"Materials Today Physics","volume":"60 ","pages":"Article 101972"},"PeriodicalIF":9.7,"publicationDate":"2025-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145689053","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}
Pub Date : 2025-12-06DOI: 10.1016/j.mtphys.2025.101979
Zhenguo Wang , Yinchang Zhao , Jun Ni , Zhenhong Dai
We present a comprehensive study of the thermoelectric properties of hexagonal Zintl-phase compounds XMg2Y2 (X=Ca, Sr, Ba; Y=As, Sb, Bi) by combining lattice dynamics and electronic transport calculations. Our results reveal that anharmonic phonon renormalization (APRN) systematically enhances the lattice thermal conductivity through modifications of the phonon velocity operator and temperature-dependent evolution of the scattering phase space. The pronounced double-band-gap feature in the phonon dispersion, arising from the significant mass mismatch between VA-group and alkaline-earth elements, promotes phonon mode localization, thereby intensifying phonon scattering despite a reduction in the weighted phase space. In addition, phonon localization is found to originate from bond anisotropy and the weak local coordination of Ca atoms, while phonon tunneling beyond the Peierls’s framework plays only a minor role in lattice thermal transport. On the electronic side, the intrinsic SOC effect of Bi atoms splits the band-edge degeneracy, suppressing the Seebeck coefficient and moderating enhancement. By combining lattice and electronic contributions, we obtain a maximum approaching unity in intrinsic CaMg2Bi2 at 700 K. Although not yet sufficient for practical devices, these findings establish 122-phase XMg2Y2 as a promising intrinsic p-type thermoelectric platform with excellent thermal stability, maintaining structural robustness even up to 1000 K, and underscore the broader importance of mass disparity, bonding anisotropy, and SOC-induced band splitting in guiding the design of next-generation thermoelectric materials
{"title":"Revisiting thermoelectric transport in 122 Zintl phases: Anharmonic phonon renormalization and phonon localization effects","authors":"Zhenguo Wang , Yinchang Zhao , Jun Ni , Zhenhong Dai","doi":"10.1016/j.mtphys.2025.101979","DOIUrl":"10.1016/j.mtphys.2025.101979","url":null,"abstract":"<div><div>We present a comprehensive study of the thermoelectric properties of hexagonal Zintl-phase compounds XMg<sub>2</sub>Y<sub>2</sub> (X=Ca, Sr, Ba; Y=As, Sb, Bi) by combining lattice dynamics and electronic transport calculations. Our results reveal that anharmonic phonon renormalization (APRN) systematically enhances the lattice thermal conductivity through modifications of the phonon velocity operator and temperature-dependent evolution of the scattering phase space. The pronounced double-band-gap feature in the phonon dispersion, arising from the significant mass mismatch between VA-group and alkaline-earth elements, promotes phonon mode localization, thereby intensifying phonon scattering despite a reduction in the weighted phase space. In addition, phonon localization is found to originate from bond anisotropy and the weak local coordination of Ca atoms, while phonon tunneling beyond the Peierls’s framework plays only a minor role in lattice thermal transport. On the electronic side, the intrinsic SOC effect of Bi atoms splits the band-edge degeneracy, suppressing the Seebeck coefficient and moderating <span><math><mrow><mi>Z</mi><mi>T</mi></mrow></math></span> enhancement. By combining lattice and electronic contributions, we obtain a maximum <span><math><mrow><mi>Z</mi><mi>T</mi></mrow></math></span> approaching unity in intrinsic CaMg<sub>2</sub>Bi<sub>2</sub> at 700 K. Although not yet sufficient for practical devices, these findings establish 122-phase XMg<sub>2</sub>Y<sub>2</sub> as a promising intrinsic p-type thermoelectric platform with excellent thermal stability, maintaining structural robustness even up to 1000 K, and underscore the broader importance of mass disparity, bonding anisotropy, and SOC-induced band splitting in guiding the design of next-generation thermoelectric materials</div></div>","PeriodicalId":18253,"journal":{"name":"Materials Today Physics","volume":"60 ","pages":"Article 101979"},"PeriodicalIF":9.7,"publicationDate":"2025-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145689106","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}
Pub Date : 2025-12-06DOI: 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 ZTmax of 1.33 at 350 K (∼20 % higher than the pristine sample) and ZTave 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.
{"title":"PbS quantum dots-derived gradient interfaces unify doping and strain for enhanced Bi0.5Sb1.5Te3 thermoelectrics","authors":"Min Ruan , Minwen Yang , Qing Cao , Wenjie Li , Yanqi Huang , Zehao Lin , Jingyi Lyu , Zeqing Hu , Jing Shuai","doi":"10.1016/j.mtphys.2025.101975","DOIUrl":"10.1016/j.mtphys.2025.101975","url":null,"abstract":"<div><div>Enhancing near-room-temperature p-type (Bi, Sb)<sub>2</sub>Te<sub>3</sub> 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 × 10<sup>19</sup> cm<sup>−3</sup> to 2.4 × 10<sup>19</sup> cm<sup>−3</sup>. Despite moderate decreases in mobility and Seebeck coefficient, a room-temperature power factor of ∼41 μW cm<sup>−1</sup> K<sup>−2</sup> is achieved. Subsequent Ga co-doping fine-tunes the carrier density and further suppresses the lattice thermal conductivity, yielding a <em>ZT</em><sub>max</sub> of 1.33 at 350 K (∼20 % higher than the pristine sample) and <em>ZT</em><sub>ave</sub> 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.</div></div>","PeriodicalId":18253,"journal":{"name":"Materials Today Physics","volume":"60 ","pages":"Article 101975"},"PeriodicalIF":9.7,"publicationDate":"2025-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145689260","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}
Pub Date : 2025-12-05DOI: 10.1016/j.mtphys.2025.101977
Leihuan Mu , Qinghua Liu , Jiehui Li , Hui Liu , Pu Feng , Ying Zhang , Jinmei He , Mengnan Qu
With the ongoing global energy transition and the implementation of the “carbon peak–carbon neutrality” strategy, electrocatalytic water splitting has been recognized as a pivotal technology for sustainable hydrogen production owing to its cleanliness and high efficiency. However, conventional powder-based electrodes still suffer from intrinsic drawbacks in electrical conductivity, structural durability, and gas evolution dynamics, making it challenging to achieve high current densities and long-term operational stability. In recent years, self-supported electrodes, benefiting from their integrated current collector–catalyst architecture, have demonstrated remarkable electron/ion transport, mechanical robustness, and highly designable three-dimensional porous structures, thereby emerging as the research frontier in electrolytic water splitting. Notably, precise regulation of electrode surface wettability has been proven to play a decisive role in governing reactant transport, bubble detachment kinetics, and the construction of triple-phase boundaries, thus serving as a key factor to enhance both catalytic activity and durability. This review highlights the synergistic interplay between wettability engineering and multidimensional strategies—including structural engineering, electronic structure modulation, interfacial engineering, and compositional regulation—revealing the intrinsic logic of cross-scale optimization for superior electrode performance. Furthermore, we propose a self-supported electrode design framework centered on the ternary synergy of “structure–wettability–electronics” and provide perspectives on dynamic wettability regulation and advanced in situ characterization techniques for predictive design and mechanistic elucidation. Collectively, this review aims to deliver theoretical insights and technological outlooks toward the rational design and industrial translation of high-performance self-supported electrodes for electrochemical water splitting.
{"title":"Self-supported electrodes for efficient water splitting: Integrating wettability with multidimensional engineering","authors":"Leihuan Mu , Qinghua Liu , Jiehui Li , Hui Liu , Pu Feng , Ying Zhang , Jinmei He , Mengnan Qu","doi":"10.1016/j.mtphys.2025.101977","DOIUrl":"10.1016/j.mtphys.2025.101977","url":null,"abstract":"<div><div>With the ongoing global energy transition and the implementation of the “carbon peak–carbon neutrality” strategy, electrocatalytic water splitting has been recognized as a pivotal technology for sustainable hydrogen production owing to its cleanliness and high efficiency. However, conventional powder-based electrodes still suffer from intrinsic drawbacks in electrical conductivity, structural durability, and gas evolution dynamics, making it challenging to achieve high current densities and long-term operational stability. In recent years, self-supported electrodes, benefiting from their integrated current collector–catalyst architecture, have demonstrated remarkable electron/ion transport, mechanical robustness, and highly designable three-dimensional porous structures, thereby emerging as the research frontier in electrolytic water splitting. Notably, precise regulation of electrode surface wettability has been proven to play a decisive role in governing reactant transport, bubble detachment kinetics, and the construction of triple-phase boundaries, thus serving as a key factor to enhance both catalytic activity and durability. This review highlights the synergistic interplay between wettability engineering and multidimensional strategies—including structural engineering, electronic structure modulation, interfacial engineering, and compositional regulation—revealing the intrinsic logic of cross-scale optimization for superior electrode performance. Furthermore, we propose a self-supported electrode design framework centered on the ternary synergy of “structure–wettability–electronics” and provide perspectives on dynamic wettability regulation and advanced in situ characterization techniques for predictive design and mechanistic elucidation. Collectively, this review aims to deliver theoretical insights and technological outlooks toward the rational design and industrial translation of high-performance self-supported electrodes for electrochemical water splitting.</div></div>","PeriodicalId":18253,"journal":{"name":"Materials Today Physics","volume":"60 ","pages":"Article 101977"},"PeriodicalIF":9.7,"publicationDate":"2025-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145689269","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}
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