Materials Today Physics最新文献

{"title":"Atomic Imprint Crystallization: Externally-Templated Crystallization of Amorphous Silicon","authors":"Koichi Tanaka, Connor P. Horn, Jianguo Wen, Rachel E. Koritala, Supratik Guha","doi":"10.1016/j.mtphys.2024.101599","DOIUrl":"https://doi.org/10.1016/j.mtphys.2024.101599","url":null,"abstract":"In this paper, we demonstrate the crystallization of an amorphous Si layer via atomic imprint crystallization (AIC), where an amorphous Si layer is crystallized by solid phase epitaxy (SPE) from an externally impressed single-crystal Si template that is then peeled off via delamination following crystallization. Microstructural analysis using electron backscattered diffraction (EBSD) and transmission electron microscopy (TEM) studies of the delaminated (crystallized) films reveals that the top surface of the amorphous Si layer is crystallized by SPE with regions (up to ∼5 mm diameter) composed of epitaxial domains (lateral size of few μm), all of which bear the same crystalline orientation as that of the template crystal. Unlike conventional SPE, the crystallization is not uniform across the entire region: the grains contain crystal defects such as dislocations, stacking faults, and twins; and while the crystallization is initiated at the top surface of the film, the thickness of the single-crystalline area is limited to ∼40 nm from the top surface. Clearly, the AIC approach leads to SPE (aligned with the template’s crystalline orientation) over areas as large as few mms, but the crystallization is defective and incomplete through the film. We attribute this to be a consequence of the tensile stress field created at the amorphous/crystalline frontline by the volume change of amorphous Si during the crystallization. Our results establish the feasibility of imprint crystallization, and points to the direction of a new process that may enable the creation of single crystal pockets in integrated device stacks in a scalable fashion without the need for an underlying single crystal substrate. However, our results also indicate that the crystallization is of a poor quality and indicates the need for further optimization of the crystallization method.","PeriodicalId":18253,"journal":{"name":"Materials Today Physics","volume":"60 1","pages":""},"PeriodicalIF":11.5,"publicationDate":"2024-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142678994","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":"Mist CVD Technology for Gallium Oxide Deposition: A Review","authors":"Suhao Yao, Yifan Yao, Maolin Zhang, Xueqiang Ji, Shan Li, Weihua Tang","doi":"10.1016/j.mtphys.2024.101604","DOIUrl":"https://doi.org/10.1016/j.mtphys.2024.101604","url":null,"abstract":"Mist chemical vapor deposition (mist CVD) technology originated from early metal organic chemical vapor deposition (MOCVD) techniques. By mist CVD, High-quality oxide films are deposited by ultrasonic atomization of low-concentration precursor solutions under atmospheric pressure and relatively low temperature conditions. Mist CVD was first reported in 1990, and in 2008, Shinohara et al. applied mist CVD to the growth of gallium oxide (Ga₂O₃) epitaxial films. As an ultrawide bandgap (UWBG) semiconductor, Ga₂O₃ has tremendous potential in power systems and optoelectronic devices, attracting significant attention and becoming a research hotspot in recent years. Various techniques have been explored for growing Ga₂O₃ films. Among them, mist CVD is noted for its relatively cheap equipment, simpler operation, and competitive cost advantages, making it a promising method for Ga₂O₃ film growth. Using mist CVD, five crystal phases (<em>α</em>, <em>β</em>, <em>γ</em>, <em>ε</em>, and <em>δ</em>) of Ga₂O₃ films have been successfully produced, and the properties of Ga₂O₃ films can be easily tuned through doping and alloy engineering. Additionally, semiconductor devices have been fabricated using Ga₂O₃ films grown by mist CVD. However, challenges remain in terms of doping uniformity, crystal phase purity, and stability. This paper reviews the advancements in mist CVD for the deposition of Ga₂O₃, covering mist CVD equipment design, Ga₂O₃ crystal phase control, doping and alloy modulation, and device fabrication.","PeriodicalId":18253,"journal":{"name":"Materials Today Physics","volume":"252 1","pages":""},"PeriodicalIF":11.5,"publicationDate":"2024-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142678333","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":"Anderson disorder related p-type conductivity and metal-insulator transition in β-Ga2O3","authors":"Zeyu Chi, Se-Rim Park, Luka Burdiladze, Tamar Tchelidze, Jean-Michel Chauveau, Yves Dumont, Sang-Mo Koo, Zurab Kushitashvili, Amiran Bibilashvili, Gérard Guillot, Amador Pérez-Tomás, Xin-Ying Tsai, Fu-Gow Tarntair, Ray Hua Horng, Ekaterine Chikoidze","doi":"10.1016/j.mtphys.2024.101602","DOIUrl":"https://doi.org/10.1016/j.mtphys.2024.101602","url":null,"abstract":"The <em>p</em>-type doping is one of the main challenges of the emerging semiconductor <em>β-</em>Ga₂O₃ technology. Phosphorus implantation has been recently reported as a novel route to achieve <em>p</em>-type conduction on Ga₂O₃ at room temperature. Here, P-implanted epilayers, grown onto <em>c</em>-plane sapphire revealed a pseudo-metallic behavior (<em>ρ</em> = 1.3 – 0.3 Ω·cm) in the 300 – 600 K range with a hole carrier concentration of <em>p</em> ⁓ 4 – 6 ×10¹⁸ cm^-3 and hole mobility of <em>μ</em> = 1.2 – 2.1 cm²/(V·s). At sufficiently low temperature, a metal-insulator transition arises together with an increase in the positive magnetoresistance, reaching up to 200% (9 T) large positive magneto resistance effect at 2 K. It is suggested that an Anderson delocalization model explains the room temperature conduction, and the transition to an insulator state caused by random variation of potential related to the incorporated phosphorous in Ga₂O₃. We believe that the lack of shallow acceptors can be mitigated by promoting Anderson disorder through the incorporation of a high level of acceptor impurities.","PeriodicalId":18253,"journal":{"name":"Materials Today Physics","volume":"2 1","pages":""},"PeriodicalIF":11.5,"publicationDate":"2024-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142679111","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":"Data-driven design of thermal-mechanical multifunctional metamaterials","authors":"Xiaochang Xing, Yanxiang Wang, Jianchang Jiang, Lingling Wu, Xiaoyong Tian, Ying Li","doi":"10.1016/j.mtphys.2024.101603","DOIUrl":"https://doi.org/10.1016/j.mtphys.2024.101603","url":null,"abstract":"Achieving effective control of thermal and mechanical distributions has been a long-standing goal, and metamaterials have emerged as a crucial tool for customizing functional structures to manipulate these physical fields. However, existing design paradigms do not apply to thermal-mechanical metamaterials that operate on thermal and mechanical fields simultaneously and independently. First, Due to the different geometric requirements imposed by the thermal and mechanical fields on the unit cells, there is a conflict between functional coupling and design coupling, which limits the design of thermal-mechanical metamaterials. Second, the fact that continuum mechanical equations do not remain invariant under general coordinate transformations hinders the application of conventional theories. Additionally, balancing minimal design costs, manufacturability, and optimal functionality remains a significant challenge. Here, we propose a global data-driven design method using Bayesian hyperparameter optimization. This method creates thermal-mechanical metamaterials from a large, pre-computed unit cell database. Our flexible method allows designing thermal-mechanical metamaterials with various functional combinations (e.g., cloaks, concentrators, and rotators) and shapes. Compared to traditional solutions, this approach balances manufacturability and functionality while offering unparalleled universality and low design costs. Experimental measurements validate the effectiveness of our method. Our approach can rapidly respond to new design scenarios and address design challenges related to the multi-physical effects.","PeriodicalId":18253,"journal":{"name":"Materials Today Physics","volume":"3 1","pages":""},"PeriodicalIF":11.5,"publicationDate":"2024-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142673399","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":"Achieving ultra-high resistivity and outstanding piezoelectric properties by co-substitution in CaBi2Nb2O9 ceramics","authors":"Biao Zhang, Liming Quan, Zhihong Luo, Qiantong Li, Jianming Deng, Shuhang Yu, Wangxin Li, Mingmei Lin, Feng Yan, Dawei Wang, Dongyan Yu, Changbai Long, Laijun Liu","doi":"10.1016/j.mtphys.2024.101598","DOIUrl":"https://doi.org/10.1016/j.mtphys.2024.101598","url":null,"abstract":"CaBi₂Nb₂O₉ (CBNO) ceramics exhibit significant potential in the development of piezoelectric sensors suitable for extreme environments such as aerospace, metallurgy, and nuclear power plants. While previous studies have enhanced the piezoelectric response of CBNO ceramics, their insulating properties at high temperatures still require improvement. In this work, co-substitution of (Li_0.5Bi_0.5) at A site and Mn at B site was designed to improve the electrical properties of CBNO ceramics. Defect dipoles induced by the bound between Mn and oxygen vacancies restrict the movement of oxygen vacancies at high temperatures. Meanwhile, co-substitution of Ca by (Li_0.5Bi_0.5) reduces both the sintering temperature and volatilization of Bi₂O₃ during the sintering process. This modification results in an ultra-high <em>T</em>_C of 928 °C and an exceptional resistivity of 2.85 MΩ·cm at 600 °C for Ca_0.96(Li_0.5Bi_0.5)_0.04Bi₂Nb_1.98Mn_0.02O₉ ceramics. Furthermore, the ceramic exhibits excellent piezoelectric properties (<em>d</em>₃₃ of 15.2 pC/N and <em>k</em>_p of 6.9%), ferroelectric properties (<em>P</em>_r of 9.42 μC/cm²), and thermal stability (degeneration of <em>d</em>₃₃ only 6% after annealing at 900 °C for 2 h). This work offers a practical strategy for simultaneously achieving both a high piezoelectric response and outstanding insulating properties in the CBNO system.","PeriodicalId":18253,"journal":{"name":"Materials Today Physics","volume":"11 1","pages":""},"PeriodicalIF":11.5,"publicationDate":"2024-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142673398","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":"Construction of bifunctional MOF-based composite electrocatalysts promoting oxygen evolution reaction and glucose oxidation reaction and its kinetic deciphering","authors":"Hongmei Yuan, Changyu Weng, Xinghua Zhang, Lungang Chen, Qi Zhang, Longlong Ma, Jianguo Liu","doi":"10.1016/j.mtphys.2024.101601","DOIUrl":"https://doi.org/10.1016/j.mtphys.2024.101601","url":null,"abstract":"The climate crisis and the need for green and sustainable energy drive the rapid development of hydrogen production from water electrolysis. Improvements in the kinetics of the anode reaction, which governs the efficiency of water electrolysis, are essential for efficient hydrogen production and key to effectively addressing global environmental and energy challenges. Hence, we focus on improving the kinetics of the anode oxidation reaction. The multi-walled carbon nanotubes coupled with bimetallic organic framework (CoFe-MOF-74) composite electrocatalysts (CoFe-MOF-74@MWCNT) were fabricated for OER and the kinetically more favorable glucose oxidation reaction (GOR). Compared to commercial RuO₂, CoFe-MOF-74@MWCNT showed superior OER catalytic performance, exhibiting a lower overpotential (273 mV) and a lower Tafel slope (55 mV dec^-1) at a current density of 10 mA cm^-2. Moreover, after adding glucose to the anode, the potential required of 10 mA cm^-2 was only 1.291 V (<em>vs.</em> RHE), a reduction of 212 mV compared to the OER potential. This reduction in potential demonstrates the efficiency of our catalysts and signifies significant energy savings. The characterization results and theoretical calculations indicated that the superior OER/GOR performance of CoFe-MOF-74@MWCNT can be ascribed to the synergistic effect between MWCNT and the mixed metal nodes of the bimetallic organic framework. The doping of MWCNT promoted the catalyst charge transfer efficiency (R_ct was only 5.56 Ω) in the OER process. The mixed metal nodes of CoFe-MOF-74@MWCNT provided more active sites for the electrocatalytic reaction, and promoted the bond-breaking of critical intermediates in the oxidation process, significantly reducing the free energy of catalytic intermediates and accelerating reaction kinetics. This work provides a strategy for designing multifunctional electrocatalysts for OER and biomass small molecule oxidation and highlights the potential for significant energy savings in practical applications.","PeriodicalId":18253,"journal":{"name":"Materials Today Physics","volume":"57 1","pages":""},"PeriodicalIF":11.5,"publicationDate":"2024-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142678334","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":"Recent Progress on High-Power 2 μm Fiber Lasers: A Comprehensive Study of Advancements, Applications, and Future Perspectives","authors":"Muhammad Tahir Sohail, Jinde Yin, Muhammad Abdullah, Muhammad Younis, Muhammad Naveed Anjum, Muhammad Tayyab Sohail, Roobaea Alroobaea, Imtiaz Ahmed, Yan Peiguang","doi":"10.1016/j.mtphys.2024.101600","DOIUrl":"https://doi.org/10.1016/j.mtphys.2024.101600","url":null,"abstract":"High-power lasers operating at the 2 μm wavelength domain have gained considerable interest in recent times owing to their distinct characteristics and versatile applications in the field of medical and industrial precision processing. This article presents a comprehensive review of high-power lasers, beginning with an overview of rare-earth silica fiber as a critical component for high-power lasers performing at 2 μm. Subsequently, the research progress of three essential high-power laser technologies – continuous-wave (CW), pulsed, and single-frequency (SF) lasers – is thoroughly analyzed, highlighting their respective strengths and limitations. Moreover, the potential of combining silica fibers with Raman technology for effective wavelength extension in 2 μm lasers is explored. Furthermore, the article emphasizes the current challenges associated with the progression of high-power fiber lasers and outlines potential avenues for future advancements.","PeriodicalId":18253,"journal":{"name":"Materials Today Physics","volume":"63 1","pages":""},"PeriodicalIF":11.5,"publicationDate":"2024-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142678335","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":"Improving electromagnetic wave absorption performance by adjusting the proportion of brittle BCC phase in FeCoNiCr0.4Mnx high-entropy alloys","authors":"Yuping Duan, Meiqi Li, Guo Yuan, Ning Zhu, Huifang Pang, Chenxu Dou","doi":"10.1016/j.mtphys.2024.101596","DOIUrl":"https://doi.org/10.1016/j.mtphys.2024.101596","url":null,"abstract":"High-entropy alloys, as a novel type of absorber, exhibit exceptional electromagnetic modulation capabilities and significant potential for electromagnetic wave absorption. In this work, the FeCoNiCrMn high-entropy alloy absorbent prepared through a mechanical alloying process demonstrates a dual-phase solid solution structure comprising face-centered cubic (FCC) and body-centered cubic (BCC) phases. By varying the manganese (Mn) content in the system, it is possible to enhance the degree of crystallinity, maintain the integrity of the crystal structure, and effectively control the relative proportion of the BCC phase within the overall phase composition. This adjustment improves the brittleness of the sheet-like particles, reduces particle size, and significantly lowers the permittivity. When the molar ratio of Mn is 0.6, the sample exhibits improved impedance matching due to the optimal permittivity and permeability. Notably, the impedance matching and attenuation constant can also be balanced. At 6.42 GHz, the FeCoNiCr_0.4Mn_0.6 alloy powder achieves the maximum reflection loss of −48.49 dB at a matching layer thickness of 3 mm. When the matching thickness is reduced to 2 mm, it can effectively cover a frequency range of 8.7–14.1 GHz (effective absorption bandwidth of 5.4 GHz), along with a wide absorption bandwidth and high absorption efficiency.","PeriodicalId":18253,"journal":{"name":"Materials Today Physics","volume":"248 1","pages":""},"PeriodicalIF":11.5,"publicationDate":"2024-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142665421","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":"Self-powered temperature pressure sensing arrays with stepped microcone structure and Bi2Te3-based films for deep learning-assisted object recognition","authors":"Yaling Wang, Yue Sun, Wenqiang Li, Pan Li, Jing Wang, Pengcheng Zhu, Shiyang Qi, Jihua Tang, Yuan Deng","doi":"10.1016/j.mtphys.2024.101588","DOIUrl":"https://doi.org/10.1016/j.mtphys.2024.101588","url":null,"abstract":"Flexible temperature-pressure bimodal sensing arrays can detect multiple types of information, including force and heat, making them crucial for applications such as object classification, human-machine interaction, and artificial intelligence. However, current sensors primarily focus on single-parameter and single-point measurements, while lacking a continuous and stable power supply. This study developed flexible, self-powered temperature-pressure sensing arrays by integrating a stepped microcone structure with thermoelectric materials. This stepped distribution microstructure design enabled effective pressure measurements across a wide range, with high sensitivity and fast response. Temperature-independent measurements were achieved synchronously over a wide temperature range (35-173 °C) by incorporating high-performance Bi₂Te₃-based thermoelectric films. These temperature and pressure sensing units can discern temperature and pressure stimuli without mutual interference. Furthermore, with the assistance of deep learning, these bimodal sensing arrays performed spatial mapping of temperature and pressure simultaneously, demonstrating their ability to identify different types of objects with an accuracy exceeding 98%. Therefore, this study shows promise for advancing human-machine interaction, artificial intelligence, and self-powered electronic skins.","PeriodicalId":18253,"journal":{"name":"Materials Today Physics","volume":"13 1","pages":""},"PeriodicalIF":11.5,"publicationDate":"2024-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142665456","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":"Fully Degradable, Highly Sensitive Pressure Sensor Based on Bipolar Electret for Biomechanical Signal Monitoring","authors":"Xingchen Ma, Yi Qin, Lian Zhou, Qianqian Hu, Xinhao Xiang, Heinz von Seggern, Sergey Zhukov, Alexander A. Altmann, Mario Kupnik, Wenxin Niu, Xiaoqing Zhang","doi":"10.1016/j.mtphys.2024.101597","DOIUrl":"https://doi.org/10.1016/j.mtphys.2024.101597","url":null,"abstract":"In view of the global ecosystem crisis resulting from the ubiquitous electronic waste (e- and plastic waste), the engineering of advanced electronic devices from sustainable materials is gaining considerable attention. Nevertheless, the development of advanced, maybe even degradable electronics with comparable or even improved functionality remains a great challenge. In this article a fabrication process for a fully degradable, highly sensitive pressure sensor based on electrets is proposed enabling the creation of a universal platform for monitoring various biomechanical signals. The high sensitivity of the proposed biomechanical electret-based sensor utilizes electrostatic induction of highly deformable cellular polylactic acid (PLA) films with a serrated ripple structure and an improved bipolar charge storage capability. This biodegradable pressure sensor possesses competitive mechanical signal detection performance, obtaining a high pressure sensitivity (10 V/kPa), robust working stability (∼30,000 continuous cycles), short electromechanical response/recovery time (∼17 ms), and satisfactory heat resistance up to 60 °C. By tailoring the thickness of the encapsulation layer, the functional lifetime of the biomechanical sensor in physiological environment can be controlled effectively, facilitating adaptability to various implantable application scenarios. Altogether, the present work not only proposes an effective fabrication process for high-performance pressure sensors, but also provides new insight into the design of sustainable electronics with controllable lifetime thereby minimizing their environmental footprint. The developed sensor promises great potential in monitoring multiple biomechanical signals inside and outside the human body (e.g., body movements and physiological activities) as well as an environment-friendly realization of green electronics.","PeriodicalId":18253,"journal":{"name":"Materials Today Physics","volume":"21 1","pages":""},"PeriodicalIF":11.5,"publicationDate":"2024-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142642742","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}