Max Huber, Jörg Schuster, Oliver G. Schmidt, Harald Kuhn, Daniil Karnaushenko
{"title":"A Mechanical–Electrical Model to Describe the Negative Differential Resistance in Membranotronic Devices","authors":"Max Huber, Jörg Schuster, Oliver G. Schmidt, Harald Kuhn, Daniil Karnaushenko","doi":"10.1002/pssr.202470010","DOIUrl":"https://doi.org/10.1002/pssr.202470010","url":null,"abstract":"","PeriodicalId":54619,"journal":{"name":"Physica Status Solidi-Rapid Research Letters","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2024-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140886964","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Spontaneously integrated multicolor InGaN micro‐LEDs with a micro‐stripe topography achieve selective electrical operation with four different color emissions: green, bluish‐green, bluish‐purple, and purple. The entire micro‐stripe displays broadband emissions because the stripe topography with a convex lens–like cross‐section induces a continuous emission wavelength gradient in the overgrown InGaN active layers. Since each wavelength component is distributed along the stripe direction, multiple narrow p‐electrodes are positioned side‐by‐side across the stripe width. This design supports selective current injection into the corresponding local areas. This work represents an important step for realizing broadband visible light emitters where individual wavelength components composing the broad spectra can be modulated and switched independently.This article is protected by copyright. All rights reserved.
具有微条纹拓扑结构的自发集成多色 InGaN 微型 LED 实现了选择性电操作，具有四种不同的发射颜色：绿色、蓝绿色、蓝紫色和紫色。整个微条纹显示出宽带发射，这是因为具有凸透镜式横截面的条纹拓扑结构在生长过度的 InGaN 有源层中诱导出连续的发射波长梯度。由于每个波长分量都沿条纹方向分布，因此在整个条纹宽度上并排设置了多个窄对电极。这种设计支持将电流有选择地注入相应的局部区域。这项工作是实现宽带可见光发射器的重要一步，在这种发射器中，构成宽光谱的各个波长成分可以独立调制和切换。本文受版权保护。
{"title":"Spontaneously integrated multicolor InGaN micro‐LEDs for spectrum‐controllable broadband light sources","authors":"Yoshinobu Matsuda, Haruyoshi Miyawaki, Mitsuru Funato, Yoichi Kawakami","doi":"10.1002/pssr.202400094","DOIUrl":"https://doi.org/10.1002/pssr.202400094","url":null,"abstract":"Spontaneously integrated multicolor InGaN micro‐LEDs with a micro‐stripe topography achieve selective electrical operation with four different color emissions: green, bluish‐green, bluish‐purple, and purple. The entire micro‐stripe displays broadband emissions because the stripe topography with a convex lens–like cross‐section induces a continuous emission wavelength gradient in the overgrown InGaN active layers. Since each wavelength component is distributed along the stripe direction, multiple narrow <jats:italic>p</jats:italic>‐electrodes are positioned side‐by‐side across the stripe width. This design supports selective current injection into the corresponding local areas. This work represents an important step for realizing broadband visible light emitters where individual wavelength components composing the broad spectra can be modulated and switched independently.This article is protected by copyright. All rights reserved.","PeriodicalId":54619,"journal":{"name":"Physica Status Solidi-Rapid Research Letters","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2024-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140829344","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Hyunmin Cho, Donghee Kang, Yeonjin Yi, Ji Hoon Park
Molybdenum disulfide (MoS2) is a representative two dimensional n‐type semiconductor for various electron devices, but its lateral conduction performances are still restricted, which is mainly attributed to the contact resistance (Rc) in field‐effect transistor. Low‐enough Rc value must be realized toward practical device fabrications. Here, we have fabricated 2D MoS2 FETs using chemical vapor deposited (CVD) MoS2 channels with and without the ultrathin LiF interlayer, to demonstrate the practical benefits of LiF. In addition, we also apply the LiF to Al metal which is known more earth‐abundant than Au, expecting the similar positive effects of the inserted LiF. When 35 CVD‐grown MoS2 channel FETs with Au were characterized on an identical gate dielectric substrate, the higher value of mobility ranging 55∽60 cm2/V s are achieved with the inserted LiF than that without LiF (∽20 cm2/V s). In the case of another MoS2 FET with exfoliated flake channel and Al contact, its field‐effect mobility with LiF insertion appears to be ∽35 cm2/V s approaching to an almost Rc‐free mobility (42 cm2/V s).This article is protected by copyright. All rights reserved.
{"title":"Ultrathin LiF insertion and ensued contact resistance reduction in MoS2 channel transistors","authors":"Hyunmin Cho, Donghee Kang, Yeonjin Yi, Ji Hoon Park","doi":"10.1002/pssr.202400121","DOIUrl":"https://doi.org/10.1002/pssr.202400121","url":null,"abstract":"Molybdenum disulfide (MoS<jats:sub>2</jats:sub>) is a representative two dimensional n‐type semiconductor for various electron devices, but its lateral conduction performances are still restricted, which is mainly attributed to the contact resistance (R<jats:sub>c</jats:sub>) in field‐effect transistor. Low‐enough R<jats:sub>c</jats:sub> value must be realized toward practical device fabrications. Here, we have fabricated 2D MoS<jats:sub>2</jats:sub> FETs using chemical vapor deposited (CVD) MoS<jats:sub>2</jats:sub> channels with and without the ultrathin LiF interlayer, to demonstrate the practical benefits of LiF. In addition, we also apply the LiF to Al metal which is known more earth‐abundant than Au, expecting the similar positive effects of the inserted LiF. When 35 CVD‐grown MoS<jats:sub>2</jats:sub> channel FETs with Au were characterized on an identical gate dielectric substrate, the higher value of mobility ranging 55∽60 cm<jats:sup>2</jats:sup>/V s are achieved with the inserted LiF than that without LiF (∽20 cm<jats:sup>2</jats:sup>/V s). In the case of another MoS<jats:sub>2</jats:sub> FET with exfoliated flake channel and Al contact, its field‐effect mobility with LiF insertion appears to be ∽35 cm<jats:sup>2</jats:sup>/V s approaching to an almost R<jats:sub>c</jats:sub>‐free mobility (42 cm<jats:sup>2</jats:sup>/V s).This article is protected by copyright. All rights reserved.","PeriodicalId":54619,"journal":{"name":"Physica Status Solidi-Rapid Research Letters","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2024-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140829343","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Hui Xiong, Deng Yang, Zhilin Chen, Yuxin Jiang, Junhua Gao, Hongtao Cao
Due to low refractive‐index and grain‐boundary‐free features, amorphous SiO2 thin films possess inherent advantages in serving as antireflective and protective layers against atmosphere. However, under high‐temperature or/and oxidation harsh environment, the thermodynamic instability of Si‐O bonds and ‘depolymerization’ process among tetrahedral units [SiO4] would result in their insufficient thermal stability and oxygen‐barrier failure. By taking amorphous network former, small element electronegativity and high oxide dissociation energy into considerations, we introduce low‐level Zr dopant to induce short‐ and medium‐range structural modification in amorphous SiO2 thin films, aiming to shorten Si‐O bond length and enhance network connectivity, respectively. As expected, the fabricated SiZrO thin films exhibit superior thermal stability and oxygen‐barrier performance without sacrificing their low‐index attribute. The Zr doping significantly elevates the oxygen‐inward‐diffusion activation energy from 0.94 eV to 1.95 eV in SiO2 network. Further, utilizing as protective layer for W‐SiO2 cermet, the SiZrO can effectively prevent the oxidation of W nanoparticles caused by oxygen inward diffusion. Undoubtedly, the exploration of amorphous SiZrO thin films offers exciting prospects for the application of functional coatings and devices under extreme conditions.This article is protected by copyright. All rights reserved.
{"title":"Improved Thermal Stability and Oxygen‐Barrier Performance of SiO2 Thin Films by Modifying Amorphous Network Structure","authors":"Hui Xiong, Deng Yang, Zhilin Chen, Yuxin Jiang, Junhua Gao, Hongtao Cao","doi":"10.1002/pssr.202400064","DOIUrl":"https://doi.org/10.1002/pssr.202400064","url":null,"abstract":"Due to low refractive‐index and grain‐boundary‐free features, amorphous SiO<jats:sub>2</jats:sub> thin films possess inherent advantages in serving as antireflective and protective layers against atmosphere. However, under high‐temperature or/and oxidation harsh environment, the thermodynamic instability of Si‐O bonds and ‘depolymerization’ process among tetrahedral units [SiO<jats:sub>4</jats:sub>] would result in their insufficient thermal stability and oxygen‐barrier failure. By taking amorphous network former, small element electronegativity and high oxide dissociation energy into considerations, we introduce low‐level Zr dopant to induce short‐ and medium‐range structural modification in amorphous SiO<jats:sub>2</jats:sub> thin films, aiming to shorten Si‐O bond length and enhance network connectivity, respectively. As expected, the fabricated SiZrO thin films exhibit superior thermal stability and oxygen‐barrier performance without sacrificing their low‐index attribute. The Zr doping significantly elevates the oxygen‐inward‐diffusion activation energy from 0.94 eV to 1.95 eV in SiO<jats:sub>2</jats:sub> network. Further, utilizing as protective layer for W‐SiO<jats:sub>2</jats:sub> cermet, the SiZrO can effectively prevent the oxidation of W nanoparticles caused by oxygen inward diffusion. Undoubtedly, the exploration of amorphous SiZrO thin films offers exciting prospects for the application of functional coatings and devices under extreme conditions.This article is protected by copyright. All rights reserved.","PeriodicalId":54619,"journal":{"name":"Physica Status Solidi-Rapid Research Letters","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2024-04-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140803736","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
One of the main challenges for modern information read and write technology is how to effectively and precisely modulate the interconversion between electricity and magnetism with a high data density. Herein, it is proposed that two‐dimensional magnetic sliding ferroelectrics can serve as a prototypical material platform with tunable electric current‐induced magnetization variation, a typical nonequilibrium magnetoelectric coupling process. Using a CrI3 bilayer as the exemplary material, first‐principles calculations are performed to enumerate the monopole values, toroidal vectors, and quadrupole moment tensors. Their switching is also elucidated under a short distance sliding between the two layers, which can effectively flip the electric dipole moment. In addition to spin polarization which is usually studied for magnetic systems, the orbital moment contribution to the magnetoelectric coupling is also evaluated. They are found to be comparable in their magnitude and neither should be omitted, as opposed to equilibrium states. The work helps to reveal the underlining mechanisms among electronics, spintronics, and orbitronics in low‐dimensional multiferroic materials.
{"title":"Current‐Induced Spin and Orbital Polarization in Magnetic Sliding Ferroelectrics","authors":"Haoxiang Dong, Jian Zhou","doi":"10.1002/pssr.202400062","DOIUrl":"https://doi.org/10.1002/pssr.202400062","url":null,"abstract":"One of the main challenges for modern information read and write technology is how to effectively and precisely modulate the interconversion between electricity and magnetism with a high data density. Herein, it is proposed that two‐dimensional magnetic sliding ferroelectrics can serve as a prototypical material platform with tunable electric current‐induced magnetization variation, a typical nonequilibrium magnetoelectric coupling process. Using a CrI<jats:sub>3</jats:sub> bilayer as the exemplary material, first‐principles calculations are performed to enumerate the monopole values, toroidal vectors, and quadrupole moment tensors. Their switching is also elucidated under a short distance sliding between the two layers, which can effectively flip the electric dipole moment. In addition to spin polarization which is usually studied for magnetic systems, the orbital moment contribution to the magnetoelectric coupling is also evaluated. They are found to be comparable in their magnitude and neither should be omitted, as opposed to equilibrium states. The work helps to reveal the underlining mechanisms among electronics, spintronics, and orbitronics in low‐dimensional multiferroic materials.","PeriodicalId":54619,"journal":{"name":"Physica Status Solidi-Rapid Research Letters","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2024-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140635719","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jayanta Bhattacharjee, Rajashri Urkude, S. D. Singh
The local structure of β‐(AlxGa1‐x)2O3 alloys for various Al contents has been determined from extended X‐ray absorption fine structure spectroscopy (EXAFS) performed at the Ga K‐edge. A model to fit the experimental EXAFS data of the monoclinic β‐(AlxGa1‐x)2O3 alloy has been suggested to independently determine relevant local structure parameters. An increase in compositional disorder corresponding to the near neighbours (NNs) for lower Al contents establishes that the Al atom does occupy tetrahedron atomic sites in addition to octahedron sites even for smaller Al contents. The NNs and next‐nearest neighbours (NNNs) bond lengths corresponding to tetrahedron and octahedron coordinated Gallium (Ga) atoms with the surrounding Oxygen (O) atoms as well as tetrahedron‐tetrahedron/octahedron‐octahedron coordinated Ga‐Ga atoms on average display a decreasing trend with the Al content up to x=33.3% and then they do not change much with a further increase in Al content. While, tetrahedron‐octahedron coordinated Ga‐Ga atoms move far from each other with the Al content up to x=33.3% and then it does not change much. The physical picture derived from the EXAFS analysis indicates the creation of tetrahedra and octahedra sublattices at the local level for β‐(AlxGa1‐x)2O3 alloys, and their sizes decrease, but they move far apart from each other up to a certain Al content. Thereafter, their sizes and the distance between them do not change much. Thus, the EXAFS results provide a clear insight into the evolution of the local structure of β‐(AlxGa1‐x)2O3 alloys with the Al content, which may be useful for a better understanding of their physical properties.This article is protected by copyright. All rights reserved.
在 Ga K 边沿进行的扩展 X 射线吸收精细结构光谱（EXAFS）测定了不同铝含量的 β-（AlxGa1-x）2O3 合金的局部结构。提出了一个拟合单斜β-(AlxGa1-x)2O3合金的EXAFS实验数据的模型，以独立确定相关的局部结构参数。铝含量较低时，与近邻（NNs）相对应的成分无序度增加，这表明即使铝含量较低，铝原子除了占据八面体原子位点外，还占据了四面体原子位点。四面体和八面体配位镓（Ga）原子与周围氧（O）原子以及四面体-四面体/八面体-八面体配位镓-镓原子对应的近邻（NNNs）键长和近邻（NNNs）键长平均随铝含量（x=33.3%）的增加而呈下降趋势，然后随着铝含量的进一步增加而变化不大。而四面体-八面体配位的镓-镓原子则随着 Al 含量的增加而彼此远离，直到 x=33.3% 时才有明显变化。从 EXAFS 分析得出的物理图像表明，β-(AlxGa1-x)2O3 合金在局部水平上产生了四面体和八面体亚晶格，它们的尺寸减小，但在一定的铝含量之前，它们之间的距离变远。此后，它们的尺寸和之间的距离变化不大。因此，EXAFS 结果清楚地揭示了随着铝含量的增加，β-(AlxGa1-x)2O3 合金局部结构的演变过程，这可能有助于更好地理解其物理性质。本文受版权保护。
{"title":"Probing Bond Length and Compositional Disorder in β‐(AlxGa1‐x)2O3 Alloys Using Extended X‐ray Absorption Fine Structure Spectroscopy","authors":"Jayanta Bhattacharjee, Rajashri Urkude, S. D. Singh","doi":"10.1002/pssr.202400068","DOIUrl":"https://doi.org/10.1002/pssr.202400068","url":null,"abstract":"The local structure of β‐(Al<jats:sub>x</jats:sub>Ga<jats:sub>1‐x</jats:sub>)<jats:sub>2</jats:sub>O<jats:sub>3</jats:sub> alloys for various Al contents has been determined from extended X‐ray absorption fine structure spectroscopy (EXAFS) performed at the Ga K‐edge. A model to fit the experimental EXAFS data of the monoclinic β‐(Al<jats:sub>x</jats:sub>Ga<jats:sub>1‐x</jats:sub>)<jats:sub>2</jats:sub>O<jats:sub>3</jats:sub> alloy has been suggested to independently determine relevant local structure parameters. An increase in compositional disorder corresponding to the near neighbours (NNs) for lower Al contents establishes that the Al atom does occupy tetrahedron atomic sites in addition to octahedron sites even for smaller Al contents. The NNs and next‐nearest neighbours (NNNs) bond lengths corresponding to tetrahedron and octahedron coordinated Gallium (Ga) atoms with the surrounding Oxygen (O) atoms as well as tetrahedron‐tetrahedron/octahedron‐octahedron coordinated Ga‐Ga atoms on average display a decreasing trend with the Al content up to x=33.3% and then they do not change much with a further increase in Al content. While, tetrahedron‐octahedron coordinated Ga‐Ga atoms move far from each other with the Al content up to x=33.3% and then it does not change much. The physical picture derived from the EXAFS analysis indicates the creation of tetrahedra and octahedra sublattices at the local level for β‐(Al<jats:sub>x</jats:sub>Ga<jats:sub>1‐x</jats:sub>)<jats:sub>2</jats:sub>O<jats:sub>3</jats:sub> alloys, and their sizes decrease, but they move far apart from each other up to a certain Al content. Thereafter, their sizes and the distance between them do not change much. Thus, the EXAFS results provide a clear insight into the evolution of the local structure of β‐(Al<jats:sub>x</jats:sub>Ga<jats:sub>1‐x</jats:sub>)<jats:sub>2</jats:sub>O<jats:sub>3</jats:sub> alloys with the Al content, which may be useful for a better understanding of their physical properties.This article is protected by copyright. All rights reserved.","PeriodicalId":54619,"journal":{"name":"Physica Status Solidi-Rapid Research Letters","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2024-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140635713","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In the present investigation, via first‐principle calculations and theoretical analysis, we systematically investigated a new Dirac semimetal carbon system called C32, which is composed of pentagonal, hexagonal, heptagonal, and octagonal carbon rings. We verified the stability of C32 by calculating the phonon dispersion, elastic constants, etc., and proposed an appropriate pathway for experimental synthesis. Besides, it is discovered that the system holds the quadruple rotation and inversion symmetry, resulting in the emergence of eight twisted Dirac cones (D1 and D2) with a highly anisotropic Fermi velocity from 3.83×105 to 8.96×105 m/s along different k directions. To substantiate the semimetallic nature of C32, we confirm its non‐trivial topological properties through the presence of topologically protected edge states and the nonzero ℤ2 topological invariant. More importantly, by introducing biaxial strain, we uncovered that Dirac cones can gradually evolve into a nodal line, and the perfect nodal line can be obtained when the biaxial strain is 13.3%. Furthermore, by constructing the tight‐binding model, we perfectly repeated the appearance of the Dirac cone and explained its evolution into the nodal line under biaxial strain.This article is protected by copyright. All rights reserved.
在本研究中，我们通过第一性原理计算和理论分析，系统研究了一种名为 C32 的新型狄拉克半金属碳体系，它由五边形、六边形、七边形和八边形碳环组成。我们通过计算声子色散、弹性常数等验证了 C32 的稳定性，并提出了合适的实验合成途径。此外，我们还发现该体系具有四重旋转和反转对称性，从而出现了八个扭曲的狄拉克锥（D1 和 D2），其费米速度沿不同的 k 方向从 3.83×105 m/s 到 8.96×105 m/s 高度各向异性。为了证实 C32 的半金属性质，我们通过拓扑保护边缘态和非零 ℤ2 拓扑不变式的存在，证实了它的非三维拓扑特性。更重要的是，通过引入双轴应变，我们发现狄拉克锥可以逐渐演化成节点线，当双轴应变为 13.3% 时，可以得到完美的节点线。此外，通过构建紧约束模型，我们完美地重现了狄拉克锥的外观，并解释了其在双轴应变下演化成结点线的原因。本文受版权保护。
{"title":"Evolution from topological nodal points to nodal line: realized in fused carbon allotrope","authors":"Jinhui Xing, Wentao Yue, Jiaren Yuan, Lizhi Zhang, Yingcong Wei, Lichuan Zhang, Yuee Xie, Yuanping Chen","doi":"10.1002/pssr.202400095","DOIUrl":"https://doi.org/10.1002/pssr.202400095","url":null,"abstract":"In the present investigation, via first‐principle calculations and theoretical analysis, we systematically investigated a new Dirac semimetal carbon system called C32, which is composed of pentagonal, hexagonal, heptagonal, and octagonal carbon rings. We verified the stability of C32 by calculating the phonon dispersion, elastic constants, etc., and proposed an appropriate pathway for experimental synthesis. Besides, it is discovered that the system holds the quadruple rotation and inversion symmetry, resulting in the emergence of eight twisted Dirac cones (D<jats:sub>1</jats:sub> and D<jats:sub>2</jats:sub>) with a highly anisotropic Fermi velocity from 3.83×10<jats:sup>5</jats:sup> to 8.96×10<jats:sup>5</jats:sup> m/s along different <jats:italic>k</jats:italic> directions. To substantiate the semimetallic nature of C32, we confirm its non‐trivial topological properties through the presence of topologically protected edge states and the nonzero ℤ<jats:sub>2</jats:sub> topological invariant. More importantly, by introducing biaxial strain, we uncovered that Dirac cones can gradually evolve into a nodal line, and the perfect nodal line can be obtained when the biaxial strain is 13.3%. Furthermore, by constructing the tight‐binding model, we perfectly repeated the appearance of the Dirac cone and explained its evolution into the nodal line under biaxial strain.This article is protected by copyright. All rights reserved.","PeriodicalId":54619,"journal":{"name":"Physica Status Solidi-Rapid Research Letters","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2024-04-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140630678","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
We propose the rotational dynamics of the intralayer and interlayer excitons with their inherent momenta of inertia in the monolayer and bilayer transition metal dichalcogenides, respectively, where the new chirality of exciton is endowed by the rotational angular momentum, namely, the formations of left‐ and right‐handed excitons at the +K and ‐K valleys, respectively. We find that angular momenta exchange between excitons and its surrounding phononic bath result in the large fluctuation of the effective g‐factor and the asymmetry of valley Zeeman splitting observed in most recently experiments, both of which sensitively depend on the magnetic moments provided by the phononic environment. This rotating exciton model not only proposes a new controllable knob in valleytronics, but opens the door to explore the angular momentum exchange of the chiral quasiparticles with the many‐body environment.This article is protected by copyright. All rights reserved.
我们提出了单层和双层过渡金属二钙化物中分别具有固有惯性矩的层内和层间激子的旋转动力学，其中激子的新手性是由旋转角动量赋予的，即在 +K 和 -K 谷分别形成左手和右手激子。我们发现，激子与其周围声波浴之间的角动量交换导致了最近大多数实验中观察到的有效 g 因子的大幅波动和谷泽曼分裂的不对称性，而这两者都敏感地依赖于声波环境提供的磁矩。这种旋转激子模型不仅为谷电学提出了一个新的可控旋钮，而且为探索手性准粒子与多体环境的角动量交换打开了大门。本文受版权保护。
{"title":"The rotating excitons in two‐dimensional materials: Valley Zeeman effect and chirality","authors":"Yu Cui, Xin-Jun Ma, Jia-Pei Deng, Shao-Juan Li, Ran-Bo Yang, Zhi-Qing Li, Zi-Wu Wang","doi":"10.1002/pssr.202400060","DOIUrl":"https://doi.org/10.1002/pssr.202400060","url":null,"abstract":"We propose the rotational dynamics of the intralayer and interlayer excitons with their inherent momenta of inertia in the monolayer and bilayer transition metal dichalcogenides, respectively, where the new chirality of exciton is endowed by the rotational angular momentum, namely, the formations of left‐ and right‐handed excitons at the +K and ‐K valleys, respectively. We find that angular momenta exchange between excitons and its surrounding phononic bath result in the large fluctuation of the effective <jats:italic>g</jats:italic>‐factor and the asymmetry of valley Zeeman splitting observed in most recently experiments, both of which sensitively depend on the magnetic moments provided by the phononic environment. This rotating exciton model not only proposes a new controllable knob in valleytronics, but opens the door to explore the angular momentum exchange of the chiral quasiparticles with the many‐body environment.This article is protected by copyright. All rights reserved.","PeriodicalId":54619,"journal":{"name":"Physica Status Solidi-Rapid Research Letters","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2024-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140630755","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
P‐type Two‐dimensional ferroelectric semiconductors (2D FeSs) play an increasingly essential role in the advanced nonvolatile and morphotropic beyond‐Moore electronic devices with high performance and low power consumption. But reliable p‐type 2D FeS with holes as majority carriers are still scarce. Here, we report the first experimental realization of room‐temperature ferroelectricity in van der Waals layered β‐In1.75Sb0.25Se3 down to fewlayer. The origin of ferroelectricity in β‐In1.75Sb0.25Se3 comes from aliovalent elemental substitution –antimony substituting to the indium sites (SbIn)– changing the local environment of the central‐layer Se atoms. Thanks to the intrinsic ferroelectric and semiconducting natures, ferroelectric semiconductor field‐effect transistor (FeSFET) devices based on β‐In1.75Sb0.25Se3 exhibits reconfigurable, multilevel nonvolatile memory (NVM) states, which can be successively modulated by gate voltage stimuli. Furthermore, the inherent operation mechanism, owing to the switchable polarization, indicates that a neuromorphic memory is also possible with our 2D FeSFETs. These presented results facilitate the technological implementation of versatile 2D FeS devices for next‐generation logic‐in‐memory approach for Internet‐of‐Things (IoT) entities.This article is protected by copyright. All rights reserved.
P 型二维铁电半导体（2D FeS）在高性能、低功耗的先进非易失性和各向异性超摩尔电子器件中发挥着越来越重要的作用。但是，以空穴为主要载流子的可靠 p 型二维 FeS 仍然非常稀缺。在此，我们报告了首次在范德华层β-In1.75Sb0.25Se3中实现室温铁电的实验结果。β-In1.75Sb0.25Se3的铁电性源于异价元素取代--锑取代铟位点（SbIn）--改变了中心层硒原子的局部环境。由于具有固有的铁电和半导体性质，基于 β-In1.75Sb0.25Se3 的铁电半导体场效应晶体管（FeSFET）器件呈现出可重新配置的多级非易失性存储器（NVM）状态，这些状态可以通过栅极电压刺激进行连续调制。此外，由于可切换极化的固有运行机制，我们的二维 FeSFET 还可以实现神经形态存储器。本文受版权保护。本文受版权保护。
{"title":"Emergence of ferroelectricity in P‐Type 2D In1.75Sb0.25Se3","authors":"Shasha Li, Tao Guo, Yong Yan, Yimin A Wu","doi":"10.1002/pssr.202400057","DOIUrl":"https://doi.org/10.1002/pssr.202400057","url":null,"abstract":"P‐type Two‐dimensional ferroelectric semiconductors (2D FeSs) play an increasingly essential role in the advanced nonvolatile and morphotropic beyond‐Moore electronic devices with high performance and low power consumption. But reliable p‐type 2D FeS with holes as majority carriers are still scarce. Here, we report the first experimental realization of room‐temperature ferroelectricity in van der Waals layered β‐In<jats:sub>1.75</jats:sub>Sb<jats:sub>0.25</jats:sub>Se<jats:sub>3</jats:sub> down to fewlayer. The origin of ferroelectricity in β‐In<jats:sub>1.75</jats:sub>Sb<jats:sub>0.25</jats:sub>Se<jats:sub>3</jats:sub> comes from aliovalent elemental substitution –antimony substituting to the indium sites (Sb<jats:sub>In</jats:sub>)– changing the local environment of the central‐layer Se atoms. Thanks to the intrinsic ferroelectric and semiconducting natures, ferroelectric semiconductor field‐effect transistor (FeSFET) devices based on β‐In<jats:sub>1.75</jats:sub>Sb<jats:sub>0.25</jats:sub>Se<jats:sub>3</jats:sub> exhibits reconfigurable, multilevel nonvolatile memory (NVM) states, which can be successively modulated by gate voltage stimuli. Furthermore, the inherent operation mechanism, owing to the switchable polarization, indicates that a neuromorphic memory is also possible with our 2D FeSFETs. These presented results facilitate the technological implementation of versatile 2D FeS devices for next‐generation logic‐in‐memory approach for Internet‐of‐Things (IoT) entities.This article is protected by copyright. All rights reserved.","PeriodicalId":54619,"journal":{"name":"Physica Status Solidi-Rapid Research Letters","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2024-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140625466","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Tian Luo, Zhehan Yu, Yijun Dai, Sitong Chen, Fang Ye, Wei Xu, Jichun Ye, Wei Guo
Reducing off‐state and gate leakage current is crucial in the development of metal‐insulator‐semiconductor high‐electron‐mobility‐transistors (MIS‐HEMTs). This work reports interface engineering in the gate recess region through low‐damage digital etching during the fabrication of normally‐off GaN MIS‐HEMTs. Conventional plasma etching leads to a reduction of the N/(Al+Ga) ratio, but this value recovered to almost 1 with optimized oxidation condition during digital etching, suggesting a reduction of the Al/Ga dangling bonds based on the proposed technique. GaN MIS‐HEMTs with digital etching exhibits a threshold voltage of 1.0 V at 1 µA/mm, a high ON/OFF current ratio of 1010, a gate breakdown voltage of 22 V, and a low gate leakage current of 10‐8 mA/mm.This article is protected by copyright. All rights reserved.
降低关态和栅极漏电流对于开发金属-绝缘体-半导体高电子迁移率晶体管 (MIS-HEMT) 至关重要。这项研究报告了在制造常关态氮化镓 MIS-HEMT 时，通过低损耗数字蚀刻技术在栅极凹槽区域进行的界面工程。传统的等离子蚀刻会导致 N/（Al+Ga）比值降低，但在数字蚀刻过程中优化氧化条件后，该值几乎恢复到 1，这表明基于所提出的技术，Al/Ga 的悬空键减少了。采用数字蚀刻技术的 GaN MIS-HEMT 在 1 µA/mm 时具有 1.0 V 的阈值电压、1010 的高导通/关断电流比、22 V 的栅极击穿电压和 10-8 mA/mm 的低栅极漏电流。本文受版权保护。
{"title":"Control of Surface Chemistry in Recess Etching Towards Normally‐OFF GaN MIS‐HEMTs","authors":"Tian Luo, Zhehan Yu, Yijun Dai, Sitong Chen, Fang Ye, Wei Xu, Jichun Ye, Wei Guo","doi":"10.1002/pssr.202400091","DOIUrl":"https://doi.org/10.1002/pssr.202400091","url":null,"abstract":"Reducing off‐state and gate leakage current is crucial in the development of metal‐insulator‐semiconductor high‐electron‐mobility‐transistors (MIS‐HEMTs). This work reports interface engineering in the gate recess region through low‐damage digital etching during the fabrication of normally‐off GaN MIS‐HEMTs. Conventional plasma etching leads to a reduction of the N/(Al+Ga) ratio, but this value recovered to almost 1 with optimized oxidation condition during digital etching, suggesting a reduction of the Al/Ga dangling bonds based on the proposed technique. GaN MIS‐HEMTs with digital etching exhibits a threshold voltage of 1.0 V at 1 µA/mm, a high ON/OFF current ratio of 10<jats:sup>10</jats:sup>, a gate breakdown voltage of 22 V, and a low gate leakage current of 10<jats:sup>‐8</jats:sup> mA/mm.This article is protected by copyright. All rights reserved.","PeriodicalId":54619,"journal":{"name":"Physica Status Solidi-Rapid Research Letters","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2024-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140625469","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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