Pub Date : 2024-07-12DOI: 10.1088/1361-6463/ad6275
Kuiyuan Tian, Yapeng Zhao, Jiangfeng Du, Q Yu
To increase the gate swing, a GaN-based high-electron-mobility transistor with a junction barrier Schottky gate (JBS-HEMT) was proposed. Compared to conventional p-GaN Schottky gate HEMTs (Conv-HEMT), the high electric field at the surface is transferred to the pn junction inside the body, and the extended depletion region of the pn junction shields the surface Schottky contact interface for the JBS-HEMT. After fitting the model to the reported device, the proposed JBS-HEMT was simulated and optimized using the Sentaurus TCAD tool. The simulation results of the optimized JBS-HEMT demonstrate a high gate breakdown voltage (17.6V), which is 158.5% higher than the gate breakdown voltage of the Conv-HEMT (11.1V) and a lower gate leakage current of six orders of magnitude than the Conv-HEMT at the gate-to-source voltage of 10V. The proposed JBS-HEMT exhibits a positive threshold voltage (1.68V) and excellent threshold voltage stability, and the maximum threshold voltage drift of the JBS-HEMT (+0.237V) is smaller than that of the Conv-HEMT (-0.714V) under gate stress conditions. The peak transconductance of the JBS-HEMT (186mS/mm) at athe drain-to-source voltage of 10V showed almost no reduction compared to the Conv-HEMT (189mS/mm), which solves the problem of decreased transconductance capability of the reported GaN HEMT with a p-n junction gate (PNJ-HEMT). It was confirmed that the JBS-HEMT has excellent gate stability and potential for power electronics applications.
{"title":"Design Optimization of Wide-Gate Swing E-Mode GaN HEMTs with Junction Barrier Schottky Gate","authors":"Kuiyuan Tian, Yapeng Zhao, Jiangfeng Du, Q Yu","doi":"10.1088/1361-6463/ad6275","DOIUrl":"https://doi.org/10.1088/1361-6463/ad6275","url":null,"abstract":"\u0000 To increase the gate swing, a GaN-based high-electron-mobility transistor with a junction barrier Schottky gate (JBS-HEMT) was proposed. Compared to conventional p-GaN Schottky gate HEMTs (Conv-HEMT), the high electric field at the surface is transferred to the pn junction inside the body, and the extended depletion region of the pn junction shields the surface Schottky contact interface for the JBS-HEMT. After fitting the model to the reported device, the proposed JBS-HEMT was simulated and optimized using the Sentaurus TCAD tool. The simulation results of the optimized JBS-HEMT demonstrate a high gate breakdown voltage (17.6V), which is 158.5% higher than the gate breakdown voltage of the Conv-HEMT (11.1V) and a lower gate leakage current of six orders of magnitude than the Conv-HEMT at the gate-to-source voltage of 10V. The proposed JBS-HEMT exhibits a positive threshold voltage (1.68V) and excellent threshold voltage stability, and the maximum threshold voltage drift of the JBS-HEMT (+0.237V) is smaller than that of the Conv-HEMT (-0.714V) under gate stress conditions. The peak transconductance of the JBS-HEMT (186mS/mm) at athe drain-to-source voltage of 10V showed almost no reduction compared to the Conv-HEMT (189mS/mm), which solves the problem of decreased transconductance capability of the reported GaN HEMT with a p-n junction gate (PNJ-HEMT). It was confirmed that the JBS-HEMT has excellent gate stability and potential for power electronics applications.","PeriodicalId":507822,"journal":{"name":"Journal of Physics D: Applied Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-07-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141654297","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}
Pub Date : 2024-07-12DOI: 10.1088/1361-6463/ad626c
H. Hajian, Matthieu Proffit, Ekmel Özbay, Pascal Landais, A. L. Bradley
Reprogrammable metasurfaces enable active modulation of light at subwavelength scales. Operating in the microwave, terahertz, and mid-infrared ranges, these metasurfaces find applications in communications, sensing, and imaging. Electrically tunable metasurfaces operating in the near-infrared (NIR) range are crucial for LiDAR applications. Achieving a NIR reprogrammable metasurface requires individual gating of nano-antennas, emphasizing effective heat management to preserve device performance. To this end, here we propose an electrically tunable Au-vanadium dioxide (VO2) metasurface design on top of a one-dimensional Si-Al2O3 photonic crystal (PC), positioned on a SiC substrate. Each individual Au-VO2 nano-antenna is switched from an Off to ON state via Joule heating, enabling the programming of the metasurface using 1-bit (binary) control. While operating as a nearly perfect reflector at λ_0=1.55 μm, the materials, thickness, and number of the layers in the PC are carefully chosen to ensure it acts as a thermal metamaterial. Moreover, with high optical efficiency (R~40% at λ_0), appropriate thermal performance, and feasibility, the metasurface also enables broadband programmable beam steering in the 1.4 μm-1.7 μm range for a wide steering angle range. This metasurface design also offers active control over NIR light transmittance, reflectance and absorptance in the wavelength range of 0.75 μm-3 μm. These characteristics render the device practical for LiDAR and active filtering.
{"title":"Reprogrammable metasurface design for NIR beam steering and active filtering","authors":"H. Hajian, Matthieu Proffit, Ekmel Özbay, Pascal Landais, A. L. Bradley","doi":"10.1088/1361-6463/ad626c","DOIUrl":"https://doi.org/10.1088/1361-6463/ad626c","url":null,"abstract":"\u0000 Reprogrammable metasurfaces enable active modulation of light at subwavelength scales. Operating in the microwave, terahertz, and mid-infrared ranges, these metasurfaces find applications in communications, sensing, and imaging. Electrically tunable metasurfaces operating in the near-infrared (NIR) range are crucial for LiDAR applications. Achieving a NIR reprogrammable metasurface requires individual gating of nano-antennas, emphasizing effective heat management to preserve device performance. To this end, here we propose an electrically tunable Au-vanadium dioxide (VO2) metasurface design on top of a one-dimensional Si-Al2O3 photonic crystal (PC), positioned on a SiC substrate. Each individual Au-VO2 nano-antenna is switched from an Off to ON state via Joule heating, enabling the programming of the metasurface using 1-bit (binary) control. While operating as a nearly perfect reflector at λ_0=1.55 μm, the materials, thickness, and number of the layers in the PC are carefully chosen to ensure it acts as a thermal metamaterial. Moreover, with high optical efficiency (R~40% at λ_0), appropriate thermal performance, and feasibility, the metasurface also enables broadband programmable beam steering in the 1.4 μm-1.7 μm range for a wide steering angle range. This metasurface design also offers active control over NIR light transmittance, reflectance and absorptance in the wavelength range of 0.75 μm-3 μm. These characteristics render the device practical for LiDAR and active filtering.","PeriodicalId":507822,"journal":{"name":"Journal of Physics D: Applied Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-07-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141654402","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}
Pub Date : 2024-07-12DOI: 10.1088/1361-6463/ad626b
Xinan Wang, Mei Ding, C. Jia
Manganese (Mn), possessing ample reserves on the earth, exhibits various oxidation states and garners significant attentions within the realm of battery technology. Mn-based flow batteries (MFBs) are recognized as viable contenders for energy storage owing to their environmentally sustainable nature, economic feasibility, and enhanced safety features. Nevertheless, the advancement of MFBs is hindered by contentious reaction mechanisms, suboptimal energy density, and inadequate cycling stability. This review offers a comprehensive analysis of various MFBs based on the specific redox couples utilized in the catholyte, including Mn3+/Mn2+, MnO2/Mn2+, and MnO4-/MnO42-. Moreover, recent advancements and concerns encountered by each type of MFBs are subsequently addressed and discussed in detail. Additionally, the current understanding of the mechanisms for different Mn-based pairs and their potentials for energy storage applications are introduced. Finally, challenges for the future development of MFBs, along with suggested improvement strategies are outlined.
{"title":"A perspective on manganese-based flow batteries","authors":"Xinan Wang, Mei Ding, C. Jia","doi":"10.1088/1361-6463/ad626b","DOIUrl":"https://doi.org/10.1088/1361-6463/ad626b","url":null,"abstract":"\u0000 Manganese (Mn), possessing ample reserves on the earth, exhibits various oxidation states and garners significant attentions within the realm of battery technology. Mn-based flow batteries (MFBs) are recognized as viable contenders for energy storage owing to their environmentally sustainable nature, economic feasibility, and enhanced safety features. Nevertheless, the advancement of MFBs is hindered by contentious reaction mechanisms, suboptimal energy density, and inadequate cycling stability. This review offers a comprehensive analysis of various MFBs based on the specific redox couples utilized in the catholyte, including Mn3+/Mn2+, MnO2/Mn2+, and MnO4-/MnO42-. Moreover, recent advancements and concerns encountered by each type of MFBs are subsequently addressed and discussed in detail. Additionally, the current understanding of the mechanisms for different Mn-based pairs and their potentials for energy storage applications are introduced. Finally, challenges for the future development of MFBs, along with suggested improvement strategies are outlined.","PeriodicalId":507822,"journal":{"name":"Journal of Physics D: Applied Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-07-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141655073","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}
Pub Date : 2024-07-12DOI: 10.1088/1361-6463/ad6276
Yifan Zhang, Wan Dong, Wen-Zhu Jia, Yuan-Hong Song
Voltage waveforms associated with the electrical asymmetry effect (EAE) have the potential to be used in the deposition of the silicon-based film, since they are expected to decouple ion energy and flux at the wafer surface, and further facilitate control of the process. In this study, a one-dimensional fluid/electron Monte Carlo hybrid model is employed to examine the EAE in a capacitively coupled argon- silane discharge, encompassing both amplitude asymmetry effect (AAE) and slope asymmetry effect (SAE). In the case of AAE, with the increasing pressure, the discharge electronegativity gradually intensifies, in conjunction with a transition of the electron heating mode from α to drift-ambipolar (DA), a reduction of the absolute value of the DC self-bias voltage, and a decrease in Ar+ content, with an increase in SiH3+ content. For SAE, the trend in the discharge characteristics with the increasing pressure is similar to that for AAE, but the details are different. In SAE, the electronegativity and bulk electric field are much enhanced, resulting in higher content of high-energy electrons and Ar+ in the bulk. In addition, the absolute value of the self-bias is lower, but shows a fewer decline with the increasing pressure. The deposition rate is lower in SAE, due to the lower electron heating efficiency. However, larger voltage drop difference between two sheaths leads to a wider range of ion energy modulation at higher pressures. This study systematically investigates and compares Ar/SiH4 discharges driven by two electrically asymmetric voltage waveforms across various parameters including electron dynamics, ion and neutral transport properties, and deposition rates, with the aim of providing valuable insights and a reference for industrial applications.
{"title":"Hybrid simulation of a capacitive Ar/SiH4 discharge driven by electrically asymmetric voltage waveforms","authors":"Yifan Zhang, Wan Dong, Wen-Zhu Jia, Yuan-Hong Song","doi":"10.1088/1361-6463/ad6276","DOIUrl":"https://doi.org/10.1088/1361-6463/ad6276","url":null,"abstract":"\u0000 Voltage waveforms associated with the electrical asymmetry effect (EAE) have the potential to be used in the deposition of the silicon-based film, since they are expected to decouple ion energy and flux at the wafer surface, and further facilitate control of the process. In this study, a one-dimensional fluid/electron Monte Carlo hybrid model is employed to examine the EAE in a capacitively coupled argon- silane discharge, encompassing both amplitude asymmetry effect (AAE) and slope asymmetry effect (SAE). In the case of AAE, with the increasing pressure, the discharge electronegativity gradually intensifies, in conjunction with a transition of the electron heating mode from α to drift-ambipolar (DA), a reduction of the absolute value of the DC self-bias voltage, and a decrease in Ar+ content, with an increase in SiH3+ content. For SAE, the trend in the discharge characteristics with the increasing pressure is similar to that for AAE, but the details are different. In SAE, the electronegativity and bulk electric field are much enhanced, resulting in higher content of high-energy electrons and Ar+ in the bulk. In addition, the absolute value of the self-bias is lower, but shows a fewer decline with the increasing pressure. The deposition rate is lower in SAE, due to the lower electron heating efficiency. However, larger voltage drop difference between two sheaths leads to a wider range of ion energy modulation at higher pressures. This study systematically investigates and compares Ar/SiH4 discharges driven by two electrically asymmetric voltage waveforms across various parameters including electron dynamics, ion and neutral transport properties, and deposition rates, with the aim of providing valuable insights and a reference for industrial applications.","PeriodicalId":507822,"journal":{"name":"Journal of Physics D: Applied Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-07-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141654718","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}
Pub Date : 2024-07-12DOI: 10.1088/1361-6463/ad626f
S. Rout, Tupan Das, Anant Shukla, Manoranjan Kar
(100-x) Sr0.7La0.3Fe11.75Co0.25O19-(x) CoFe2O4 composites were synthesized by the one pot sol-gel auto-combustion method. The individual phase purity, morphology, and magnetic hysteresis loop of the composite magnet were analyzed by X-ray powder diffraction, field emission scanning electron microscopy, and vibrating sample magnetometer, respectively. The apparent observation of room temperature hysteresis loop indicates the existence of interfacial exchange interaction. Nevertheless, saturation magnetization (Ms) follows the trend of Vegard’s law. The nature of magnetic interaction and its dependency on the amount of each phase were analyzed by employing the Thamm-Hesse plot. The critical size of the soft phase particle did not corroborate with the results of ∆M vs H plot. However, this synthesis method is found to be successful in obtaining single-step magnetization reversal in hard-soft composite magnets. The deviation from ideal non-interacting Stoner-Wohlfarth particles puts the single hard phase into the limelight. The (BH)max in the range of 1.07-0.98 MGOe has been obtained for the synthesized composite magnet.
采用一锅溶胶-凝胶自动燃烧法合成了 (100-x) Sr0.7La0.3Fe11.75Co0.25O19-(x) CoFe2O4 复合材料。分别采用 X 射线粉末衍射、场发射扫描电子显微镜和振动样品磁力计分析了复合磁体的单相纯度、形貌和磁滞回线。室温磁滞回线的明显观测结果表明存在界面交换相互作用。然而，饱和磁化（Ms）遵循维加定律的趋势。利用 Thamm-Hesse 图分析了磁性相互作用的性质及其与各相量的关系。软相颗粒的临界尺寸与 ∆M vs H 图的结果并不一致。不过，这种合成方法成功地在软硬复合磁体中获得了单步磁化反转。与理想的非相互作用斯通纳-沃尔法特粒子的偏差使单一硬磁相成为焦点。合成的复合磁体获得了 1.07-0.98 MGOe 范围内的（BH）最大值。
{"title":"Magnetic interaction in Sr0.7La0.3Fe11.75Co0.25O19 - CoFe2O4 composite system: Observation, evidence, and influence","authors":"S. Rout, Tupan Das, Anant Shukla, Manoranjan Kar","doi":"10.1088/1361-6463/ad626f","DOIUrl":"https://doi.org/10.1088/1361-6463/ad626f","url":null,"abstract":"\u0000 (100-x) Sr0.7La0.3Fe11.75Co0.25O19-(x) CoFe2O4 composites were synthesized by the one pot sol-gel auto-combustion method. The individual phase purity, morphology, and magnetic hysteresis loop of the composite magnet were analyzed by X-ray powder diffraction, field emission scanning electron microscopy, and vibrating sample magnetometer, respectively. The apparent observation of room temperature hysteresis loop indicates the existence of interfacial exchange interaction. Nevertheless, saturation magnetization (Ms) follows the trend of Vegard’s law. The nature of magnetic interaction and its dependency on the amount of each phase were analyzed by employing the Thamm-Hesse plot. The critical size of the soft phase particle did not corroborate with the results of ∆M vs H plot. However, this synthesis method is found to be successful in obtaining single-step magnetization reversal in hard-soft composite magnets. The deviation from ideal non-interacting Stoner-Wohlfarth particles puts the single hard phase into the limelight. The (BH)max in the range of 1.07-0.98 MGOe has been obtained for the synthesized composite magnet.","PeriodicalId":507822,"journal":{"name":"Journal of Physics D: Applied Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-07-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141654511","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}
Pub Date : 2024-07-12DOI: 10.1088/1361-6463/ad6273
Jie Chen, Yawei Tan, Rong Wang, Qiang Zhou, yong cao, Xiaohui Ling
The spin-orbit interaction (SOI) of light manifests as the generation of spin-dependent vortex beams when a spin-polarized beam strikes an optical interface normally. However, the spin-momentum nature of this SOI process remains elusive, which impedes further manipulation. Here, we systematically investigate the spin-momentum properties of the transmitted beam in this SOI process using a full-wave theory. The transmitted beam has three components, a spin-maintained normal mode, a spin-reversed abnormal mode, and a longitudinal component. By decomposing the total spin angular momentum (SAM) into the transverse SAM (T-SAM) and the helicity dependent longitudinal SAM (L-SAM), we demonstrate that the L-SAM dominates the total SAM of the normal mode, while the T-SAM dictates that of the abnormal mode. The underlying physics is that the normal mode exhibits a much larger weight than the longitudinal field, while the abnormal mode has a weight comparable to the longitudinal field. This study enriches the understanding of the spin-momentum nature of light's SOI and offers new opportunities for manipulating light's angular momentum.
光的自旋轨道相互作用（SOI）表现为自旋偏振光束正常撞击光学界面时产生的自旋相关涡流束。然而，这种 SOI 过程的自旋动量性质仍然难以捉摸，这阻碍了进一步的操作。在这里，我们利用全波理论系统地研究了这种 SOI 过程中透射光束的自旋动量特性。透射光束有三个分量，即自旋保持正常模式、自旋反转异常模式和纵向分量。通过将总自旋角动量分解为横向自旋角动量（T-SAM）和与螺旋相关的纵向自旋角动量（L-SAM），我们证明 L-SAM 主导正常模式的总自旋角动量，而 T-SAM 则决定异常模式的总自旋角动量。其基本物理原理是正常模式的权重远大于纵向场，而异常模式的权重与纵向场相当。这项研究丰富了人们对光的 SOI 的自旋动量性质的理解，并为操纵光的角动量提供了新的机遇。
{"title":"Spin-momentum properties of the spin-orbit interactions of light at optical interfaces","authors":"Jie Chen, Yawei Tan, Rong Wang, Qiang Zhou, yong cao, Xiaohui Ling","doi":"10.1088/1361-6463/ad6273","DOIUrl":"https://doi.org/10.1088/1361-6463/ad6273","url":null,"abstract":"\u0000 The spin-orbit interaction (SOI) of light manifests as the generation of spin-dependent vortex beams when a spin-polarized beam strikes an optical interface normally. However, the spin-momentum nature of this SOI process remains elusive, which impedes further manipulation. Here, we systematically investigate the spin-momentum properties of the transmitted beam in this SOI process using a full-wave theory. The transmitted beam has three components, a spin-maintained normal mode, a spin-reversed abnormal mode, and a longitudinal component. By decomposing the total spin angular momentum (SAM) into the transverse SAM (T-SAM) and the helicity dependent longitudinal SAM (L-SAM), we demonstrate that the L-SAM dominates the total SAM of the normal mode, while the T-SAM dictates that of the abnormal mode. The underlying physics is that the normal mode exhibits a much larger weight than the longitudinal field, while the abnormal mode has a weight comparable to the longitudinal field. This study enriches the understanding of the spin-momentum nature of light's SOI and offers new opportunities for manipulating light's angular momentum.","PeriodicalId":507822,"journal":{"name":"Journal of Physics D: Applied Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-07-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141655078","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}
Ultrafast thermally induced magnetization switching (TIMS) with femtosecond lasers has attracted much attention due to its ability to trigger a single switching on the picosecond time scale. Currently, most of the studies on TIMS have focused on various ferrimagnetic alloys. In this paper, TIMS of Gd/Fe multilayers in different monolayer ratios is investigated by atomic spin dynamics. The results show that an increase in the monolayer Gd ratio narrows the energy density window of the switching. Further studies found that a lower damping ratio decreases the laser energy density threshold for magnetization reversal. Moreover, reducing the ratio of Gd in the monolayer at the appropriate energy density can shorten the duration of the transient ferromagnetic-like state, which can lead to faster realization of TIMS. Our simulation results provide new insights to explore the physical mechanism of TIMS in Gd/Fe multilayers.
{"title":"Effect of monolayer ratio on single-shot all-optical switching in Gd/Fe multilayers","authors":"Caijiang Jiang, Donglin Liu, Xinyu Song, Suiyan Tan, Chudong Xu","doi":"10.1088/1361-6463/ad6272","DOIUrl":"https://doi.org/10.1088/1361-6463/ad6272","url":null,"abstract":"\u0000 Ultrafast thermally induced magnetization switching (TIMS) with femtosecond lasers has attracted much attention due to its ability to trigger a single switching on the picosecond time scale. Currently, most of the studies on TIMS have focused on various ferrimagnetic alloys. In this paper, TIMS of Gd/Fe multilayers in different monolayer ratios is investigated by atomic spin dynamics. The results show that an increase in the monolayer Gd ratio narrows the energy density window of the switching. Further studies found that a lower damping ratio decreases the laser energy density threshold for magnetization reversal. Moreover, reducing the ratio of Gd in the monolayer at the appropriate energy density can shorten the duration of the transient ferromagnetic-like state, which can lead to faster realization of TIMS. Our simulation results provide new insights to explore the physical mechanism of TIMS in Gd/Fe multilayers.","PeriodicalId":507822,"journal":{"name":"Journal of Physics D: Applied Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-07-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141654038","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}
Pub Date : 2024-07-11DOI: 10.1088/1361-6463/ad61fa
Jiu-sheng Li, Yao-Yao Xue, Feng-lei Guo
In order to achieve a highly sensitive biosensor with a simple structure, we propose a chiral metasurface polarization sensor. Using immunological surface plasmon resonance (SPR) detection, the antigen or antibody is fixed as a probe on the SPR metasurface to detect the corresponding antibody or antigen. Through the change of the refractive index of the analyte on the surface facial mask, the terahertz signal changes, and finally the sensing detection of avian influenza virus can be achieved. The designed metasurface adopts a hollow split sector chiral structure to generate chiral surface current, which can convert linearly polarized incident waves as elliptical polarized waves. The structure achieves the high sensitivity of 401 deg/RIU at frequency of 0.8THz, and the avian influenza virus (H1N1, H5N2 and H9N2) with the same real part of the refractive index can also be distinguished. Influenza viruses belong to the family Orthomyxoviridae of RNA viruses, divided into three types: A, B, and C. In this article, avian influenza viruses belong to type A influenza viruses. It can clearly identify different Avian Influenza Viruses by the two polarization characteristic parameters of the reflection spectrum PEA (Polarization Ellipse Angle) and PRA (Polarization Rotation Angle). This method has a significant application prospect in the fields of biomedicine and food industries.
{"title":"Highly sensitive terahertz polarization biosensor utilizing chiral metasurface","authors":"Jiu-sheng Li, Yao-Yao Xue, Feng-lei Guo","doi":"10.1088/1361-6463/ad61fa","DOIUrl":"https://doi.org/10.1088/1361-6463/ad61fa","url":null,"abstract":"\u0000 In order to achieve a highly sensitive biosensor with a simple structure, we propose a chiral metasurface polarization sensor. Using immunological surface plasmon resonance (SPR) detection, the antigen or antibody is fixed as a probe on the SPR metasurface to detect the corresponding antibody or antigen. Through the change of the refractive index of the analyte on the surface facial mask, the terahertz signal changes, and finally the sensing detection of avian influenza virus can be achieved. The designed metasurface adopts a hollow split sector chiral structure to generate chiral surface current, which can convert linearly polarized incident waves as elliptical polarized waves. The structure achieves the high sensitivity of 401 deg/RIU at frequency of 0.8THz, and the avian influenza virus (H1N1, H5N2 and H9N2) with the same real part of the refractive index can also be distinguished. Influenza viruses belong to the family Orthomyxoviridae of RNA viruses, divided into three types: A, B, and C. In this article, avian influenza viruses belong to type A influenza viruses. It can clearly identify different Avian Influenza Viruses by the two polarization characteristic parameters of the reflection spectrum PEA (Polarization Ellipse Angle) and PRA (Polarization Rotation Angle). This method has a significant application prospect in the fields of biomedicine and food industries.","PeriodicalId":507822,"journal":{"name":"Journal of Physics D: Applied Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141655478","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}
Pub Date : 2024-07-11DOI: 10.1088/1361-6463/ad61f6
Ling Luo, Nengtao Wu, Zhiheng Xing, Shanjie Li, Fanyin Zeng, Ben Cao, Changtong Wu, Guoqiang Li
In this letter, a depletion-mode GaN high-electron mobility transistors (GaN HEMTs) with high breakdown voltage and low on-resistance are designed and experimentally demonstrated. It combines the gate field plate and partial u-GaN cap layer (Gate Field Plate and Partial u-GaN Cap HEMTs: GPU-HEMTs) to co-modulate the surface electric field distribution, which results in the electric field peak being far away from the gate edge, thus improving the breakdown voltage and decreasing the on-resistance. The optimized GPU-HEMTs exhibit a larger output current (I DS) of 495 mA/mm and a correspondingly smaller specific on-resistance of 4.26 mΩ·cm2. Meanwhile, a high breakdown voltage of 1044 V at I DS = 1 mA/mm compared to the conventional GaN HEMTs of 633 V was obtained. This approach is highly effective in simultaneously optimizing the breakdown voltage and the specific on-resistance of GaN HEMTs, while maintaining a large output current.
本文设计并实验演示了一种具有高击穿电压和低导通电阻的耗尽型氮化镓高电子迁移率晶体管（GaN HEMTs）。它结合了栅极场板和部分 u-GaN 盖层（栅极场板和部分 u-GaN 盖层 HEMTs：GPU-HEMTs）来共同调节表面电场分布，从而使电场峰值远离栅极边缘，从而提高了击穿电压并降低了导通电阻。优化后的 GPU-HEMT 输出电流（I DS）更大，达到 495 mA/mm，导通电阻相应更小，为 4.26 mΩ-cm2。同时，与传统 GaN HEMT 的 633 V 击穿电压相比，在 I DS = 1 mA/mm 时可获得 1044 V 的高击穿电压。这种方法在同时优化氮化镓 HEMT 的击穿电压和特定导通电阻方面非常有效，同时还能保持较大的输出电流。
{"title":"Breakdown voltage enhancement and specific on-resistance reduction in depletion-mode GaN HEMTs by co-modulating electric field","authors":"Ling Luo, Nengtao Wu, Zhiheng Xing, Shanjie Li, Fanyin Zeng, Ben Cao, Changtong Wu, Guoqiang Li","doi":"10.1088/1361-6463/ad61f6","DOIUrl":"https://doi.org/10.1088/1361-6463/ad61f6","url":null,"abstract":"\u0000 In this letter, a depletion-mode GaN high-electron mobility transistors (GaN HEMTs) with high breakdown voltage and low on-resistance are designed and experimentally demonstrated. It combines the gate field plate and partial u-GaN cap layer (Gate Field Plate and Partial u-GaN Cap HEMTs: GPU-HEMTs) to co-modulate the surface electric field distribution, which results in the electric field peak being far away from the gate edge, thus improving the breakdown voltage and decreasing the on-resistance. The optimized GPU-HEMTs exhibit a larger output current (I\u0000 DS) of 495 mA/mm and a correspondingly smaller specific on-resistance of 4.26 mΩ·cm2. Meanwhile, a high breakdown voltage of 1044 V at I\u0000 DS = 1 mA/mm compared to the conventional GaN HEMTs of 633 V was obtained. This approach is highly effective in simultaneously optimizing the breakdown voltage and the specific on-resistance of GaN HEMTs, while maintaining a large output current.","PeriodicalId":507822,"journal":{"name":"Journal of Physics D: Applied Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141658357","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}
Pub Date : 2024-07-11DOI: 10.1088/1361-6463/ad61f8
Mengya Huang, Qi-Zhi Lang, Wang Yi, Xiang Guo, Zhao Ding, Jiang Yan, Xuefei Liu
Abundant studies demonstrate the significant role of Janus-structured two dimensional semiconductors as photocatalytic materials, highlighting their substantial advantages and importance in photocatalysis. In this work, CrXCN4(X = Si, Ge) Janus monolayers were constructed based on CrC2N4, and the thermal stability, thermodynamic stability, mechanical stability, electronic properties, and optical properties of the monolayers were systematically investigated. Furthermore, an investigation was conducted to examine the impact of biaxial strain on their electrical and light absorption properties. The findings reveal that both monolayers exhibit direct band gap characteristics, with high absorption coefficients for visible light owing to their appropriate band gaps (1.44 eV for CrSiCN4 and 1.15 eV for CrGeCN4, respectively). At compressive strains exceeding 3%, the CrSiCN4monolayer demonstrates an optimal band edge position, suggesting its potential as a photocatalyst for overall water splitting. Furthermore, as the compressive strain increases, the absorption spectra have blue-shifted and the absorption coefficient becomes higher, exceeding 2×105/cm under a -3% compressive strain. Our study highlights the potential applications of CrXCN4monolayers in the field of optoelectronic device, particularly emphasizing the promising candidacy of CrSiCN4 as an efficient photocatalyst.
{"title":"First-principles Study on the Electronic Structure and Photocatalytic Properties of Novel Two-dimensional JanusCrXCN4(X = Si, Ge)","authors":"Mengya Huang, Qi-Zhi Lang, Wang Yi, Xiang Guo, Zhao Ding, Jiang Yan, Xuefei Liu","doi":"10.1088/1361-6463/ad61f8","DOIUrl":"https://doi.org/10.1088/1361-6463/ad61f8","url":null,"abstract":"\u0000 Abundant studies demonstrate the significant role of Janus-structured two dimensional semiconductors as photocatalytic materials, highlighting their substantial advantages and importance in photocatalysis. In this work, CrXCN4(X = Si, Ge) Janus monolayers were constructed based on CrC2N4, and the thermal stability, thermodynamic stability, mechanical stability, electronic properties, and optical properties of the monolayers were systematically investigated. Furthermore, an investigation was conducted to examine the impact of biaxial strain on their electrical and light absorption properties. The findings reveal that both monolayers exhibit direct band gap characteristics, with high absorption coefficients for visible light owing to their appropriate band gaps (1.44 eV for CrSiCN4 and 1.15 eV for CrGeCN4, respectively). At compressive strains exceeding 3%, the CrSiCN4monolayer demonstrates an optimal band edge position, suggesting its potential as a photocatalyst for overall water splitting. Furthermore, as the compressive strain increases, the absorption spectra have blue-shifted and the absorption coefficient becomes higher, exceeding 2×105/cm under a -3% compressive strain. Our study highlights the potential applications of CrXCN4monolayers in the field of optoelectronic device, particularly emphasizing the promising candidacy of CrSiCN4 as an efficient photocatalyst.","PeriodicalId":507822,"journal":{"name":"Journal of Physics D: Applied Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141656752","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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