In this study, a framework to determine the dynamic flow stress equation of materials based on discrete data of varied (or instantaneous) strain-rate from split Hopkinson pressure bar (SHPB) experiments is proposed. The conventional constant strain-rate requirement in SHPB test is purposely relaxed to generate rich dynamic flow stress data which are widely and diversely distributed in plastic strain and strain-rate space. Two groups of independent SHPB tests, i.e. Group A (without shaper) and Group B (with shaper) were conducted on the C54400 phosphor-bronze copper alloy at room temperature, obtaining flow stress data (FSD) (two-dimensional (2D) matrix). Data qualification criteria were proposed to screen the FSD, with which qualified FSD were obtained. The qualified FSD of Group A were coarsely filled with missing data and were reconstructed by the Artificial Neural Network (ANN). As a result, finely-filled FSD of Group A were obtained, which were carefully evaluated by the qualified FSD of Group B. The evaluation proves the effectiveness of ANN in FSD prediction. Next, the finely-filled FSD from Group A were decomposed by Singular Value Decomposition (SVD) method. Discrete and analytical flow stress equation f(strain, strain-rate)_ana were obtained from the SVD results. Finally, flow stress equation (f(strain, strain-rate)_MJC) based on conventional method were established. Five uncertainties inherent in the conventional method in the determination of the flow stress equation were identified. The comparison between f(strain, strain-rate)_ana and f(strain, strain-rate)_MJC demonstrated the effectiveness and reliability of the flow stress equation obtained from the proposed method.
本研究提出了一种基于分体式霍普金森压力棒（SHPB）实验中变化（或瞬时）应变速率离散数据来确定材料动态流动应力方程的框架。为了生成在塑性应变和应变率空间中分布广泛且多样化的丰富动态流动应力数据，特意放宽了 SHPB 试验中的传统恒定应变率要求。在室温下，对 C54400 磷青铜合金进行了两组独立的 SHPB 试验，即 A 组（无整形器）和 B 组（有整形器），获得了流动应力数据（FSD）（二维（2D）矩阵）。提出了筛选 FSD 的数据鉴定标准，并根据这些标准获得了合格的 FSD。对 A 组的合格 FSD 进行缺失数据粗填充，并通过人工神经网络（ANN）进行重建。结果得到了 A 组的精细填充 FSD，并用 B 组的合格 FSD 对其进行了仔细评估。接下来，用正弦值分解（SVD）方法对 A 组的精细填充 FSD 进行分解。最后，建立了基于传统方法的流动应力方程（f(strain, strain-rate)_MJC）。确定了传统方法在确定流动应力方程时固有的五个不确定性。通过对 f（应变、应变率）_ana 和 f（应变、应变率）_MJC 的比较，证明了拟议方法得到的流动应力方程的有效性和可靠性。
{"title":"Determination of dynamic flow stress equation based on discrete experimental data: Part 1 Methodology and the dependence of dynamic flow stress on strain-rate","authors":"Xianglin Huang, Q. M. Li","doi":"arxiv-2409.04697","DOIUrl":"https://doi.org/arxiv-2409.04697","url":null,"abstract":"In this study, a framework to determine the dynamic flow stress equation of\u0000materials based on discrete data of varied (or instantaneous) strain-rate from\u0000split Hopkinson pressure bar (SHPB) experiments is proposed. The conventional\u0000constant strain-rate requirement in SHPB test is purposely relaxed to generate\u0000rich dynamic flow stress data which are widely and diversely distributed in\u0000plastic strain and strain-rate space. Two groups of independent SHPB tests,\u0000i.e. Group A (without shaper) and Group B (with shaper) were conducted on the\u0000C54400 phosphor-bronze copper alloy at room temperature, obtaining flow stress\u0000data (FSD) (two-dimensional (2D) matrix). Data qualification criteria were\u0000proposed to screen the FSD, with which qualified FSD were obtained. The\u0000qualified FSD of Group A were coarsely filled with missing data and were\u0000reconstructed by the Artificial Neural Network (ANN). As a result,\u0000finely-filled FSD of Group A were obtained, which were carefully evaluated by\u0000the qualified FSD of Group B. The evaluation proves the effectiveness of ANN in\u0000FSD prediction. Next, the finely-filled FSD from Group A were decomposed by\u0000Singular Value Decomposition (SVD) method. Discrete and analytical flow stress\u0000equation f(strain, strain-rate)_ana were obtained from the SVD results.\u0000Finally, flow stress equation (f(strain, strain-rate)_MJC) based on\u0000conventional method were established. Five uncertainties inherent in the\u0000conventional method in the determination of the flow stress equation were\u0000identified. The comparison between f(strain, strain-rate)_ana and f(strain,\u0000strain-rate)_MJC demonstrated the effectiveness and reliability of the flow\u0000stress equation obtained from the proposed method.","PeriodicalId":501083,"journal":{"name":"arXiv - PHYS - Applied Physics","volume":"10 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142177779","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Varghese Alapatt, Francisco Marques-Moros, Carla Boix-Constant, Samuel Manas-Valero, Kirill Bolotin, Josep Canet-Ferrer, Eugenio Coronado
Single photons emitters (SPEs) are key components in quantum information applications and are commonly generated in 2D materials by inhomogeneous strain engineering. Here, we report an alternative approach that involves a 2D semiconductor/2D magnet heterostructure. The optical study of the WSe2/CrSBr heterostructures reveals several new emission lines at lower energies compared to characteristic WSe2 emissions, that are assigned to localized excitons. Further investigation demonstrates that one of these emergent lines is an SPE with a strong valley polarization response and large energy shift with the field-induced metamagnetic transition in CrSBr, linking it to the magnetic proximity effect of the adjacent CrSBr layer. In contrast to previous reports on WSe2 that only allow tuning of the SPEs by out-of-plane magnetic field, our emitter is sensitive to both in- and out-of-plane fields. Our findings demonstrate the potential of this approach for improved control and polarization of SPEs in 2D materials.
{"title":"Highly polarized single photon emitter from intrinsic localized excitons in a WSe2/CrSBr heterostructure","authors":"Varghese Alapatt, Francisco Marques-Moros, Carla Boix-Constant, Samuel Manas-Valero, Kirill Bolotin, Josep Canet-Ferrer, Eugenio Coronado","doi":"arxiv-2409.04749","DOIUrl":"https://doi.org/arxiv-2409.04749","url":null,"abstract":"Single photons emitters (SPEs) are key components in quantum information\u0000applications and are commonly generated in 2D materials by inhomogeneous strain\u0000engineering. Here, we report an alternative approach that involves a 2D\u0000semiconductor/2D magnet heterostructure. The optical study of the WSe2/CrSBr\u0000heterostructures reveals several new emission lines at lower energies compared\u0000to characteristic WSe2 emissions, that are assigned to localized excitons.\u0000Further investigation demonstrates that one of these emergent lines is an SPE\u0000with a strong valley polarization response and large energy shift with the\u0000field-induced metamagnetic transition in CrSBr, linking it to the magnetic\u0000proximity effect of the adjacent CrSBr layer. In contrast to previous reports\u0000on WSe2 that only allow tuning of the SPEs by out-of-plane magnetic field, our\u0000emitter is sensitive to both in- and out-of-plane fields. Our findings\u0000demonstrate the potential of this approach for improved control and\u0000polarization of SPEs in 2D materials.","PeriodicalId":501083,"journal":{"name":"arXiv - PHYS - Applied Physics","volume":"8 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142177781","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Mathias Casiulis, Eden Arbel, Yoav Lahini, Stefano Martiniani, Naomi Oppenheimer, Matan Yah Ben Zion
We present a geometric design rule for size-controlled clustering of self-propelled particles. Active particles that tend to rotate under an external force have an intrinsic signed-parameter with units of curvature, which we term curvity, derivable from first principles. Robot experiments and numerical simulations show that the properties of the individual robot alone -- radius and curvity -- control pair-cohesion in a binary system as well as the stability of flocking and clustering in a swarm. Our results have applications in meta-materials and embodied decentralized control.
{"title":"A geometric condition for robot-swarm cohesion and cluster-flock transition","authors":"Mathias Casiulis, Eden Arbel, Yoav Lahini, Stefano Martiniani, Naomi Oppenheimer, Matan Yah Ben Zion","doi":"arxiv-2409.04618","DOIUrl":"https://doi.org/arxiv-2409.04618","url":null,"abstract":"We present a geometric design rule for size-controlled clustering of\u0000self-propelled particles. Active particles that tend to rotate under an\u0000external force have an intrinsic signed-parameter with units of curvature,\u0000which we term curvity, derivable from first principles. Robot experiments and\u0000numerical simulations show that the properties of the individual robot alone --\u0000radius and curvity -- control pair-cohesion in a binary system as well as the\u0000stability of flocking and clustering in a swarm. Our results have applications\u0000in meta-materials and embodied decentralized control.","PeriodicalId":501083,"journal":{"name":"arXiv - PHYS - Applied Physics","volume":"44 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142177796","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Reciprocity is one of the fundamental characteristics of wave propagation in linear time-invariant media with preserved time-reversal symmetry. Breaking reciprocity opens the way to numerous applications in the fields of phononics and photonics, as it allows the unidirectional transport of information and energy carried by waves. In acoustics, achieving non-reciprocal behavior remains a challenge, for which time-varying media are one of the solutions. Here, we design and experimentally demonstrate a three-port non-reciprocal acoustic scatterer that behaves as a circulator for audible sound, by actively modulating the effective mass of the acoustic membranes over time. We discuss the conception and experimental validation of such an acoustic circulator, implemented with actively controlled loudspeakers, in the realm of audible and airborne acoustics, and demonstrate its good performance in different scenarios.
{"title":"Experimental realization of an active time-modulated acoustic circulator","authors":"Matthieu Malléjac, Romain Fleury","doi":"arxiv-2409.04251","DOIUrl":"https://doi.org/arxiv-2409.04251","url":null,"abstract":"Reciprocity is one of the fundamental characteristics of wave propagation in\u0000linear time-invariant media with preserved time-reversal symmetry. Breaking\u0000reciprocity opens the way to numerous applications in the fields of phononics\u0000and photonics, as it allows the unidirectional transport of information and\u0000energy carried by waves. In acoustics, achieving non-reciprocal behavior\u0000remains a challenge, for which time-varying media are one of the solutions.\u0000Here, we design and experimentally demonstrate a three-port non-reciprocal\u0000acoustic scatterer that behaves as a circulator for audible sound, by actively\u0000modulating the effective mass of the acoustic membranes over time. We discuss\u0000the conception and experimental validation of such an acoustic circulator,\u0000implemented with actively controlled loudspeakers, in the realm of audible and\u0000airborne acoustics, and demonstrate its good performance in different\u0000scenarios.","PeriodicalId":501083,"journal":{"name":"arXiv - PHYS - Applied Physics","volume":"152 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142177800","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Wave energy harvesting is critical for advancing the development and utilization of marine resources. In this study, we present a novel multi-roller structure triboelectric nanogenerator (MR-TENG) designed specifically for efficient water wave energy harvesting. The MR-TENG leverages a coupled multi-roller design to significantly enhance its energy harvesting capabilities. The triboelectric layers are composed of polytetrafluoroethylene (PTFE) film and paper, with a grid copper electrode serving as the conductive element. Through an optimized energy output strategy, a single MR-TENG is capable of generating 602.045 {mu}J of electrical energy within 100 s. The device achieves a short-circuit current (Isc) of approximately 2.06 {mu}A and an open-circuit voltage (Voc) of around 166 V. We further investigate the impact of different connection modes, including parallel and series configurations, on the performance of MR-TENG arrays. Notably, the electrical energy produced by the MR-TENG array is sufficient to power 40 blue commercial light-emitting diodes (LEDs). This research not only introduces a versatile optimization approach and energy management strategy for roller-structured TENGs but also contributes significantly to the advancement of ocean-based TENG technology.
{"title":"Multi-Roller Structure Triboelectric Nanogenerator for Enhanced Water Wave Energy Harvesting and Energy Management","authors":"Kequan Xia, Zhiwei Xu, Lizhong Wang, Min Yu","doi":"arxiv-2409.03601","DOIUrl":"https://doi.org/arxiv-2409.03601","url":null,"abstract":"Wave energy harvesting is critical for advancing the development and\u0000utilization of marine resources. In this study, we present a novel multi-roller\u0000structure triboelectric nanogenerator (MR-TENG) designed specifically for\u0000efficient water wave energy harvesting. The MR-TENG leverages a coupled\u0000multi-roller design to significantly enhance its energy harvesting\u0000capabilities. The triboelectric layers are composed of polytetrafluoroethylene\u0000(PTFE) film and paper, with a grid copper electrode serving as the conductive\u0000element. Through an optimized energy output strategy, a single MR-TENG is\u0000capable of generating 602.045 {mu}J of electrical energy within 100 s. The\u0000device achieves a short-circuit current (Isc) of approximately 2.06 {mu}A and\u0000an open-circuit voltage (Voc) of around 166 V. We further investigate the\u0000impact of different connection modes, including parallel and series\u0000configurations, on the performance of MR-TENG arrays. Notably, the electrical\u0000energy produced by the MR-TENG array is sufficient to power 40 blue commercial\u0000light-emitting diodes (LEDs). This research not only introduces a versatile\u0000optimization approach and energy management strategy for roller-structured\u0000TENGs but also contributes significantly to the advancement of ocean-based TENG\u0000technology.","PeriodicalId":501083,"journal":{"name":"arXiv - PHYS - Applied Physics","volume":"11 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142177798","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Recently, low-frequency mechanical energy harvesters based on solid-liquid contact electrification have garnered widespread attention for their unique advantages in wear resistance, high charge transfer efficiency, and novel insights into electron-ion interactions at the solid-liquid interface, particularly in material identification. Hence, we designed an robust and efficient water cup triboelectric nanogenerator (WC-TENG) that only uses ordinary drinking water and plastic water cups as primary materials, achieving high-efficiency power output while eliminating the need for metal electrodes and effectively addressing the issue of corrosion in generator components. Experimental results indicate that, at an operating frequency of 2 Hz, the WC-TENG generates an open-circuit voltage (Voc) of 249.71 V, a short-circuit current (Isc) of 4.21 uA, and a transferred charge (Qsc) of 188.85 nC. The WC-TENG demonstrates long-term stability and reliability, maintaining stable voltage output over 1500 s. Moreover, the WC-TENG maintains stable performance under high humidity conditions, and its output enhances with increasing temperature, underscoring its robustness and adaptability for diverse environmental applications. Furthermore, the introduction of ethanol disrupts the potential balance at the solid-liquid interface by impeding electron transfer and reducing the WC-TENG's electrical output, but as the ethanol volatilizes, the device gradually returns to its original potential state, demonstrating its potential as a selective ethanol sensor. This design not only advances the development of corrosion-resistant, high-performance energy harvesters but also opens up new possibilities for low-cost, sustainable, and environmentally adaptable sensing technologies.
{"title":"Highly robust and efficient metal-free water cup solid-liquid triboelectric generator for mechanical energy harvesting and ethanol detection","authors":"Kequan Xia, Min Yu","doi":"arxiv-2409.03604","DOIUrl":"https://doi.org/arxiv-2409.03604","url":null,"abstract":"Recently, low-frequency mechanical energy harvesters based on solid-liquid\u0000contact electrification have garnered widespread attention for their unique\u0000advantages in wear resistance, high charge transfer efficiency, and novel\u0000insights into electron-ion interactions at the solid-liquid interface,\u0000particularly in material identification. Hence, we designed an robust and\u0000efficient water cup triboelectric nanogenerator (WC-TENG) that only uses\u0000ordinary drinking water and plastic water cups as primary materials, achieving\u0000high-efficiency power output while eliminating the need for metal electrodes\u0000and effectively addressing the issue of corrosion in generator components.\u0000Experimental results indicate that, at an operating frequency of 2 Hz, the\u0000WC-TENG generates an open-circuit voltage (Voc) of 249.71 V, a short-circuit\u0000current (Isc) of 4.21 uA, and a transferred charge (Qsc) of 188.85 nC. The\u0000WC-TENG demonstrates long-term stability and reliability, maintaining stable\u0000voltage output over 1500 s. Moreover, the WC-TENG maintains stable performance\u0000under high humidity conditions, and its output enhances with increasing\u0000temperature, underscoring its robustness and adaptability for diverse\u0000environmental applications. Furthermore, the introduction of ethanol disrupts\u0000the potential balance at the solid-liquid interface by impeding electron\u0000transfer and reducing the WC-TENG's electrical output, but as the ethanol\u0000volatilizes, the device gradually returns to its original potential state,\u0000demonstrating its potential as a selective ethanol sensor. This design not only\u0000advances the development of corrosion-resistant, high-performance energy\u0000harvesters but also opens up new possibilities for low-cost, sustainable, and\u0000environmentally adaptable sensing technologies.","PeriodicalId":501083,"journal":{"name":"arXiv - PHYS - Applied Physics","volume":"38 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142177797","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Zichen Xi, Joseph G. Thomas, Jun Ji, Dongyao Wang, Zengyu Cen, Ivan I. Kravchenko, Bernadeta R. Srijanto, Yu Yao, Yizheng Zhu, Linbo Shao
Low-phase-noise microwave-frequency integrated oscillators provide compact solutions for various applications in signal processing, communications, and sensing. Surface acoustic waves (SAW), featuring orders-of-magnitude shorter wavelength than electromagnetic waves at the same frequency, enable integrated microwave-frequency systems with much smaller footprint on chip. SAW devices also allow higher quality (Q) factors than electronic components at room temperature. Here, we demonstrate a low-phase-noise gigahertz-frequency SAW oscillator on 128{deg}Y-cut lithium niobate, where the SAW resonator occupies a footprint of 0.05 mm$^2$. Leveraging phononic crystal bandgap-edge modes to balance between Q factors and insertion losses, our 1-GHz SAW oscillator features a low phase noise of -132.5 dBc/Hz at a 10 kHz offset frequency and an overlapping Hadamard deviation of $6.5times10^{-10}$ at an analysis time of 64 ms. The SAW resonator-based oscillator holds high potential in developing low-noise sensors and acousto-optic integrated circuits.
{"title":"Low-phase-noise surface acoustic wave oscillator using phononic crystal bandgap-edge mode","authors":"Zichen Xi, Joseph G. Thomas, Jun Ji, Dongyao Wang, Zengyu Cen, Ivan I. Kravchenko, Bernadeta R. Srijanto, Yu Yao, Yizheng Zhu, Linbo Shao","doi":"arxiv-2409.03162","DOIUrl":"https://doi.org/arxiv-2409.03162","url":null,"abstract":"Low-phase-noise microwave-frequency integrated oscillators provide compact\u0000solutions for various applications in signal processing, communications, and\u0000sensing. Surface acoustic waves (SAW), featuring orders-of-magnitude shorter\u0000wavelength than electromagnetic waves at the same frequency, enable integrated\u0000microwave-frequency systems with much smaller footprint on chip. SAW devices\u0000also allow higher quality (Q) factors than electronic components at room\u0000temperature. Here, we demonstrate a low-phase-noise gigahertz-frequency SAW\u0000oscillator on 128{deg}Y-cut lithium niobate, where the SAW resonator occupies\u0000a footprint of 0.05 mm$^2$. Leveraging phononic crystal bandgap-edge modes to\u0000balance between Q factors and insertion losses, our 1-GHz SAW oscillator\u0000features a low phase noise of -132.5 dBc/Hz at a 10 kHz offset frequency and an\u0000overlapping Hadamard deviation of $6.5times10^{-10}$ at an analysis time of 64\u0000ms. The SAW resonator-based oscillator holds high potential in developing\u0000low-noise sensors and acousto-optic integrated circuits.","PeriodicalId":501083,"journal":{"name":"arXiv - PHYS - Applied Physics","volume":"31 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142177801","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Damien MichezLAPLACE-CS, Juliette LetellierNEEL - SC2G, Imane HammasNEEL - SC2G, Julien PernotNEEL - SC2G, Nicolas C. RougerLAPLACE-CS
This letter presents the bulk diamond field-effect transistor (FET) with the highest current value reported at this moment. The goal was to drastically increase the current of this type of device by increasing the total gate width thanks to an interdigitated architecture and homogeneous growth properties. We report the results obtained by fabricating and characterizing an interdigitated junction FET (JFET). The device develops a total gate width of 14.7 mm, with 24 paralleled fingers and a current higher than 50 mA at VDS = -15 V, VGS = 0 V, at 450 K and under illumination which is the highest value reported for a bulk diamond FET. Its specific ON-resistance and threshold voltage are respectively 608 m$Omega$.cm${}^2$, 50 V. From Transfer length method (TLM) measurements we extract a resistivity of 3.6 m$Omega$.cm for a heavily boron-doped (p++)-diamond layer and 1.52 $Omega$.cm for a 2.1017 cm-3 p-doped diamond layer at 450 K. We measured the drain current versus gate voltage characteristics at high temperature showing that it is no longer the conduction channel resistance but the device access resistance that is predominant. This study indicates that it is possible to drastically improve the ON-state of FETs by using an interdigitated architecture, while using homogeneous large size diamond layers grown by CVD.
这封信介绍了目前所报道的电流值最高的块状金刚石场效应晶体管（FET）。我们的目标是通过增加栅极总宽度来大幅提高这类器件的电流，而这要归功于相互咬合的结构和均匀的生长特性。本报告介绍了通过制造和鉴定交错结场效应晶体管（JFET）获得的结果。该器件的栅极总宽度为 14.7 mm，有 24 个并联指，在 450 K 和照明条件下，当 VDS = -15 V、VGS = 0 V 时，电流高于 50 mA，这是目前所报道的体金刚石场效应晶体管的最高值。其比导通电阻和阈值电压分别为 608 m$Omega$.cm${}^2$ 和 50 V。根据转移长度法（TLM）测量，我们得出在 450 K 时，重度掺硼（p++）金刚石层的电阻率为 3.6 m$Omega$.cm，而 2.1017 cm-3 p 掺杂金刚石层的电阻率为 1.52 $Omega$.cm。这项研究表明，在使用通过 CVD 生长的均质大尺寸金刚石层的同时，通过使用相互咬合的结构可以大幅改善场效应晶体管的导通状态。
{"title":"Over 50 mA current in interdigitated diamond field effect transistor","authors":"Damien MichezLAPLACE-CS, Juliette LetellierNEEL - SC2G, Imane HammasNEEL - SC2G, Julien PernotNEEL - SC2G, Nicolas C. RougerLAPLACE-CS","doi":"arxiv-2409.03293","DOIUrl":"https://doi.org/arxiv-2409.03293","url":null,"abstract":"This letter presents the bulk diamond field-effect transistor (FET) with the\u0000highest current value reported at this moment. The goal was to drastically\u0000increase the current of this type of device by increasing the total gate width\u0000thanks to an interdigitated architecture and homogeneous growth properties. We\u0000report the results obtained by fabricating and characterizing an interdigitated\u0000junction FET (JFET). The device develops a total gate width of 14.7 mm, with 24\u0000paralleled fingers and a current higher than 50 mA at VDS = -15 V, VGS = 0 V,\u0000at 450 K and under illumination which is the highest value reported for a bulk\u0000diamond FET. Its specific ON-resistance and threshold voltage are respectively\u0000608 m$Omega$.cm${}^2$, 50 V. From Transfer length method (TLM) measurements we\u0000extract a resistivity of 3.6 m$Omega$.cm for a heavily boron-doped\u0000(p++)-diamond layer and 1.52 $Omega$.cm for a 2.1017 cm-3 p-doped diamond\u0000layer at 450 K. We measured the drain current versus gate voltage\u0000characteristics at high temperature showing that it is no longer the conduction\u0000channel resistance but the device access resistance that is predominant. This\u0000study indicates that it is possible to drastically improve the ON-state of FETs\u0000by using an interdigitated architecture, while using homogeneous large size\u0000diamond layers grown by CVD.","PeriodicalId":501083,"journal":{"name":"arXiv - PHYS - Applied Physics","volume":"53 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142177799","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
High thermoelectric properties are associated with the phonon-glass electron-crystal paradigm. Conventional wisdom suggests that the optimal bandgap of semiconductor to achieve the largest power factor should be between 6 and 10 kbT. To address challenges related to the bipolar effect and temperature limitations, we present findings on Zintl-type TlAgI2, which demonstrates an exceptionally low lattice thermal conductivity of 0.3 W m-1 K-1 at 300 K. The achieved figure of merit (ZT) for TlAgI2, featuring a 1.55 eV bandgap, reaches a value of 2.20 for p-type semiconductor. This remarkable ZT is attributed to the existence of extended antibonding states Ag-I in the valence band. Furthermore, the bonding hierarchy, influencing phonon anharmonicity, and coordination bonds, facilitating electron transfer between the ligand and the central metal ion, significantly contribute to electronic transport. This finding serves as a promising avenue for the development of high ZT materials with wide bandgaps at elevated temperatures.
高热电特性与声子-玻璃-电子-晶体范式有关。传统观点认为，要达到最大功率因数，半导体的最佳带隙应在 6 到 10 kbT 之间。为了应对与双极效应和温度限制有关的挑战，我们展示了对 Zintl 型 TlAgI2 的研究结果，该材料在 300 K 时的晶格热导率极低，仅为 0.3 W m-1 K-1。TlAgI2 的优点系数（ZT）为 1.55 eV 带隙，达到了 p 型半导体的 2.20 值。这一显著的 ZT 值归因于价带中存在扩展的反键态 Ag-I。此外，影响声子谐波的成键层次和促进配体与中心金属离子间电子转移的配位键也对电子传输起了重要作用。这一发现为在高温条件下开发具有宽带隙的高 ZT 材料提供了前景广阔的途径。
{"title":"Bonding Hierarchy and Coordination Interaction Leading to High Thermoelectricity in Wide Bandgap TlAgI2","authors":"Xiaoying Wang, Mengyang Li, Minxuan Feng, Xuejie Li, Yuzhou Hao, Wen Shi, Jiangang He, Xiangdong Ding, Zhibin Gao","doi":"arxiv-2409.03229","DOIUrl":"https://doi.org/arxiv-2409.03229","url":null,"abstract":"High thermoelectric properties are associated with the phonon-glass\u0000electron-crystal paradigm. Conventional wisdom suggests that the optimal\u0000bandgap of semiconductor to achieve the largest power factor should be between\u00006 and 10 kbT. To address challenges related to the bipolar effect and\u0000temperature limitations, we present findings on Zintl-type TlAgI2, which\u0000demonstrates an exceptionally low lattice thermal conductivity of 0.3 W m-1 K-1\u0000at 300 K. The achieved figure of merit (ZT) for TlAgI2, featuring a 1.55 eV\u0000bandgap, reaches a value of 2.20 for p-type semiconductor. This remarkable ZT\u0000is attributed to the existence of extended antibonding states Ag-I in the\u0000valence band. Furthermore, the bonding hierarchy, influencing phonon\u0000anharmonicity, and coordination bonds, facilitating electron transfer between\u0000the ligand and the central metal ion, significantly contribute to electronic\u0000transport. This finding serves as a promising avenue for the development of\u0000high ZT materials with wide bandgaps at elevated temperatures.","PeriodicalId":501083,"journal":{"name":"arXiv - PHYS - Applied Physics","volume":"2016 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142177803","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This paper introduces a simplified and design-oriented version of the EPFL HEMT model [1], focusing on the normalized transconductance-to-current characteristic (Gm/ID ). Relying on these figures, insights into GaN HEMT modeling in relation to technology offers a comprehensive understanding of the device behavior. Validation is achieved through measured transfer characteristics of GaN HEMTs fabricated at IMEC on a broad range of biases. This simplified approach should enable a simple and effective circuit design methodology with AlGaN/GaN HEMT heterostructures.
本文介绍了 EPFLHEMT 模型[1]的简化和面向设计的版本，重点是归一化跨导-电流特性（Gm/ID）。根据这些数据，我们深入了解了与技术相关的 GaN HEMT 模型，从而对器件行为有了全面的认识。通过测量在 IMEC 制造的氮化镓 HEMT 在各种偏压下的传输特性，验证了这一简化方法。
{"title":"Simplified EPFL GaN HEMT Model","authors":"Farzan Jazaeri, Majid Shalchian, Ashkhen Yesayan, Amin Rassekh, Anurag Mangla, Bertrand Parvais, Jean-Michel Sallese","doi":"arxiv-2409.03589","DOIUrl":"https://doi.org/arxiv-2409.03589","url":null,"abstract":"This paper introduces a simplified and design-oriented version of the EPFL\u0000HEMT model [1], focusing on the normalized transconductance-to-current\u0000characteristic (Gm/ID ). Relying on these figures, insights into GaN HEMT\u0000modeling in relation to technology offers a comprehensive understanding of the\u0000device behavior. Validation is achieved through measured transfer\u0000characteristics of GaN HEMTs fabricated at IMEC on a broad range of biases.\u0000This simplified approach should enable a simple and effective circuit design\u0000methodology with AlGaN/GaN HEMT heterostructures.","PeriodicalId":501083,"journal":{"name":"arXiv - PHYS - Applied Physics","volume":"5 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142223491","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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