The Schottky contact between metal electrode and armchair graphene nanoribbon (AGNR) plays a fundamental role in limiting the current flow as well as the overall device characteristics. To improve device performance, the metal electrode must be engineered to lower barrier height and allow low‐resistance ohmic contact. Nevertheless, in most cases this gives rise to interfacial states which dictate the contact properties and induce Fermi level pinning. Here we demonstrate another strategy to form robust and transparent 7‐atom‐wide‐AGNR (7‐AGNR)/Au contacts in which direct C‐Au σ bond is initialized by the tip of scanning tunneling microscope (STM) on a dehydrogenated terminus. This process has led to a total lift‐off of 7‐AGNR from the Au(111) substrate and allowed us to visualize the details of the band structure of 7‐AGNR. Furthermore, we find GNR useful as a STM tip for high‐resolution selective imaging of edge states showing a unique interference pattern with a periodicity that coincides with half of Fermi wavelength of GNR lattice. The combination of imaging and tunneling spectroscopy with GNR‐tip is promising for unraveling intrinsic details in the band structure which are of fundamental importance to understand the transport properties of GNRs devices.This article is protected by copyright. All rights reserved.
{"title":"Robust Contact by Direct Formation of C‐Au Bond in Suspended Armchair Graphene Nanoribbon","authors":"Abdou Hassanien","doi":"10.1002/pssr.202400192","DOIUrl":"https://doi.org/10.1002/pssr.202400192","url":null,"abstract":"The Schottky contact between metal electrode and armchair graphene nanoribbon (AGNR) plays a fundamental role in limiting the current flow as well as the overall device characteristics. To improve device performance, the metal electrode must be engineered to lower barrier height and allow low‐resistance ohmic contact. Nevertheless, in most cases this gives rise to interfacial states which dictate the contact properties and induce Fermi level pinning. Here we demonstrate another strategy to form robust and transparent 7‐atom‐wide‐AGNR (7‐AGNR)/Au contacts in which direct C‐Au σ bond is initialized by the tip of scanning tunneling microscope (STM) on a dehydrogenated terminus. This process has led to a total lift‐off of 7‐AGNR from the Au(111) substrate and allowed us to visualize the details of the band structure of 7‐AGNR. Furthermore, we find GNR useful as a STM tip for high‐resolution selective imaging of edge states showing a unique interference pattern with a periodicity that coincides with half of Fermi wavelength of GNR lattice. The combination of imaging and tunneling spectroscopy with GNR‐tip is promising for unraveling intrinsic details in the band structure which are of fundamental importance to understand the transport properties of GNRs devices.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":"2024-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141518741","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}
Wide‐bandgap zinc oxide (ZnO)‐based light‐emitting diodes (LEDs) have attracted considerable interest for application in solid‐state lighting; however, the absence of dependable high‐quality homojunctions has impeded their progress. A p‐n homojunction LED is fabricated in this study using arc discharge‐fabricated N‐doped ZnO nanoparticles (NPs) spin‐coated over a Ga‐doped ZnO thin film. The homojunction LEDs demonstrate pure ultraviolet (UV) emissions with a narrow linewidth even at elevated temperatures. The UV intensity initially increases as the injection current increases to the saturation limit with a change in the peak position, followed by a decrease at higher injection currents. A proportion of UV light is down‐converted into visible light using phosphors. Furthermore, the mixing of phosphors and their application to a UV‐LED results in white emission with high color rendering and superior optical stability. Notably, the visible spectral peaks do not discernibly change with variations in the operating current. These findings represent significant advancements in the development of stable p‐type ZnO nanostructures, leading to the development of cost‐effective photonic devices.This article is protected by copyright. All rights reserved.
基于宽带隙氧化锌（ZnO）的发光二极管（LED）在固态照明中的应用引起了人们的极大兴趣；然而，由于缺乏可靠的高质量同质结，阻碍了其发展。本研究利用电弧放电制造出的掺杂 N 的氧化锌纳米颗粒（NPs）旋涂在掺杂 Ga 的氧化锌薄膜上，制造出了 p-n 同质结 LED。这种同质结 LED 即使在高温下也能发出线宽较窄的纯紫外线 (UV) 光。当注入电流增加到饱和极限时，紫外线强度会随着峰值位置的变化而增加，随后在注入电流较大时会减弱。一部分紫外光通过荧光粉向下转换为可见光。此外，混合荧光粉并将其应用于紫外发光二极管可产生白光，具有高显色性和出色的光学稳定性。值得注意的是，可见光谱峰值不会随着工作电流的变化而发生明显变化。这些发现标志着在开发稳定的 p 型氧化锌纳米结构方面取得了重大进展，有助于开发出具有成本效益的光子设备。本文受版权保护。
{"title":"Full‐Color Electroluminescence from ZnO‐Nanoparticles‐based Homojunction Diodes","authors":"Raj Deep, Toshiyuki Yoshida, Yasuhisa Fujita","doi":"10.1002/pssr.202400149","DOIUrl":"https://doi.org/10.1002/pssr.202400149","url":null,"abstract":"Wide‐bandgap zinc oxide (ZnO)‐based light‐emitting diodes (LEDs) have attracted considerable interest for application in solid‐state lighting; however, the absence of dependable high‐quality homojunctions has impeded their progress. A p‐n homojunction LED is fabricated in this study using arc discharge‐fabricated N‐doped ZnO nanoparticles (NPs) spin‐coated over a Ga‐doped ZnO thin film. The homojunction LEDs demonstrate pure ultraviolet (UV) emissions with a narrow linewidth even at elevated temperatures. The UV intensity initially increases as the injection current increases to the saturation limit with a change in the peak position, followed by a decrease at higher injection currents. A proportion of UV light is down‐converted into visible light using phosphors. Furthermore, the mixing of phosphors and their application to a UV‐LED results in white emission with high color rendering and superior optical stability. Notably, the visible spectral peaks do not discernibly change with variations in the operating current. These findings represent significant advancements in the development of stable p‐type ZnO nanostructures, leading to the development of cost‐effective photonic devices.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":"2024-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141518743","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}
Feyza Sonmez, Sukru Ardali, Burcu Arpapay, Selman Mutlu, Ayse Aygul Ergurhan, Onur Senel, Ugur Serincan, Ayse Erol, Engin Tiras
The novel XOR, OR, and NAND optical logic gates have been investigated using GaAs‐based Hot Electron Light Emission and Lasing in Semiconductor Heterostructures (HELLISH) devices. The HELLISH devices are fabricated in the Top Hat Hot HELLISH (TH‐HELLISH) geometry to achieve a non‐linear potential distribution at the p‐n junction which consists of a 13 nm thick GaAs quantum well placed on the n‐side of the junction. Logic gates whose input part is designed as an electric field output beam incorporate four independent contacts to the p‐ and n‐type layers. Electroluminescence measurements of the output beam are performed by applying a pulsed voltage of approximately 150 V with a pulse width of 200 ns and a frequency of 20 kHz to the contacts of the TH‐HELLISH device. At room temperature, the primary emission wavelength of the optical logic gates is around 840±1 nm. It is expected that optical logic gates obtained using this type of GaAs semiconductor structure have crucial potential to be components for high‐speed optical communication technology due to their simplicity, polarity‐independent operation, and emission wavelength.This article is protected by copyright. All rights reserved.
{"title":"Light Logic Gates with GaAs‐Based Structures","authors":"Feyza Sonmez, Sukru Ardali, Burcu Arpapay, Selman Mutlu, Ayse Aygul Ergurhan, Onur Senel, Ugur Serincan, Ayse Erol, Engin Tiras","doi":"10.1002/pssr.202400173","DOIUrl":"https://doi.org/10.1002/pssr.202400173","url":null,"abstract":"The novel XOR, OR, and NAND optical logic gates have been investigated using GaAs‐based Hot Electron Light Emission and Lasing in Semiconductor Heterostructures (HELLISH) devices. The HELLISH devices are fabricated in the Top Hat Hot HELLISH (TH‐HELLISH) geometry to achieve a non‐linear potential distribution at the p‐n junction which consists of a 13 nm thick GaAs quantum well placed on the n‐side of the junction. Logic gates whose input part is designed as an electric field output beam incorporate four independent contacts to the p‐ and n‐type layers. Electroluminescence measurements of the output beam are performed by applying a pulsed voltage of approximately 150 V with a pulse width of 200 ns and a frequency of 20 kHz to the contacts of the TH‐HELLISH device. At room temperature, the primary emission wavelength of the optical logic gates is around 840±1 nm. It is expected that optical logic gates obtained using this type of GaAs semiconductor structure have crucial potential to be components for high‐speed optical communication technology due to their simplicity, polarity‐independent operation, and emission wavelength.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":"2024-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141518744","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}
With a specific focus on graphene‐ferrite nanocomposites, this comprehensive review provides insight into their nonlinear and optical limiting features. The intriguing combination of graphene electronic structure and the versatility of ferrites results in a diverse range of composites materials with exceptional properties. This unique synergy opens up numerous practical applications across different sectors. The review paper, which primarily focuses on recent advances in research, delves into the structural characteristics and attributes of these hybrids, highlighting their behaviour in nonlinear refraction, nonlinear absorption and optical limiting. Further, the explorations of cutting edge strategies for the development of wavelength and intensity dependent optical limiters are detailed. Additionally, there view paper emphasizes the challenges that still need to be overcome to fully utilise graphene‐ ferrite composites in nonlinear optical process and optical limiting.This article is protected by copyright. All rights reserved.
{"title":"Nonlinear and Optical Limiting Properties of Graphene‐Ferrite Nanocomposites: A Review","authors":"M. Saravanan","doi":"10.1002/pssr.202400105","DOIUrl":"https://doi.org/10.1002/pssr.202400105","url":null,"abstract":"With a specific focus on graphene‐ferrite nanocomposites, this comprehensive review provides insight into their nonlinear and optical limiting features. The intriguing combination of graphene electronic structure and the versatility of ferrites results in a diverse range of composites materials with exceptional properties. This unique synergy opens up numerous practical applications across different sectors. The review paper, which primarily focuses on recent advances in research, delves into the structural characteristics and attributes of these hybrids, highlighting their behaviour in nonlinear refraction, nonlinear absorption and optical limiting. Further, the explorations of cutting edge strategies for the development of wavelength and intensity dependent optical limiters are detailed. Additionally, there view paper emphasizes the challenges that still need to be overcome to fully utilise graphene‐ ferrite composites in nonlinear optical process and optical limiting.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":"2024-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141503423","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}
The linear and nonlinear Hall effects in 2D electron gas are considered theoretically within the isotropic k‐cubed Rashba model. We show that the presence of an out‐of‐plane external magnetic field or net magnetization is a necessary condition to induce a nonzero Berry curvature in the system, whereas an in‐plane magnetic field tunes the Berry curvature leading to the Berry curvature dipole. Interestingly, in the linear response regime, the conductivity is dominated by the intrinsic component (Berry curvature component), whereas the second‐order correction to the Hall current (i.e., the conductivity proportional to the external electric field) is dominated by the component independent of the Berry curvature dipole.This article is protected by copyright. All rights reserved.
我们在各向同性 k 立方体拉什巴模型中从理论上研究了二维电子气中的线性和非线性霍尔效应。我们的研究表明，平面外磁场或净磁化的存在是在系统中产生非零贝里曲率的必要条件，而平面内磁场则会调整贝里曲率，从而产生贝里曲率偶极子。有趣的是，在线性响应机制中，电导率由本征分量（贝里曲率分量）主导，而霍尔电流的二阶修正（即与外部电场成比例的电导率）则由与贝里曲率偶极子无关的分量主导。本文受版权保护。
{"title":"Nonlinear Hall effect in isotropic k‐cubed Rashba model: Berry‐curvature‐dipole engineering by in‐plane magnetic field","authors":"A. Krzyżewska, A. Dyrdal","doi":"10.1002/pssr.202400123","DOIUrl":"https://doi.org/10.1002/pssr.202400123","url":null,"abstract":"The linear and nonlinear Hall effects in 2D electron gas are considered theoretically within the isotropic k‐cubed Rashba model. We show that the presence of an out‐of‐plane external magnetic field or net magnetization is a necessary condition to induce a nonzero Berry curvature in the system, whereas an in‐plane magnetic field tunes the Berry curvature leading to the Berry curvature dipole. Interestingly, in the linear response regime, the conductivity is dominated by the intrinsic component (Berry curvature component), whereas the second‐order correction to the Hall current (i.e., the conductivity proportional to the external electric field) is dominated by the component independent of the Berry curvature dipole.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":"2024-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141518745","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}
Jinlin Wang, Qi Liu, Ran Feng, Haotian Ye, Xifan Xu, Rui Wang, Tao Wang, Xinqiang Wang
High‐quality aluminum (Al) /silicon (Si) heterojunction is crucial in a wide range of applications, such as superconductivity, interfacial heat exchanging, interconnection of Si‐based transistors, etc. However, serious Al/Si heterointerface degradation has been observed when operating at relatively higher temperatures. Understanding the interfacial atomic diffusion is thus a vital step for improving the Al/Si interface quality. We report the atomic diffusion behavior at an epitaxial Al/Si interface via in‐situ heating in Cs‐corrected scanning transmission electron microscopy (STEM). After heating to 493 ± 20 K, the Al/Si interface gradually migrates towards the Al side. This interfacial atomic migration is more active along grain boundaries due to weaker bonding between atoms caused by misorientation of grains. The new interface exhibits a trapezoidal shape, characterized by a slanted smooth left facet and a stepped right facet. This distinct morphology is attributed to minimizing the interfacial energy. Additionally, the migrated Si atoms tend to form a new nanocrystal following the initial lattice orientation in Al, while the diffused Al atoms are usually randomly inserted into the Si lattice matrix among a large region, which can be attributed to lower bonding energy of Al compared with Si.This article is protected by copyright. All rights reserved.
高质量的铝（Al）/硅（Si）异质结在超导、界面热交换、硅基晶体管互连等广泛应用中至关重要。然而，在相对较高的温度下工作时，人们发现铝/硅异质结表面退化严重。因此，了解界面原子扩散是提高铝/硅界面质量的关键一步。我们利用铯校正扫描透射电子显微镜（STEM）报告了通过原位加热在铝/硅外延界面上的原子扩散行为。加热到 493 ± 20 K 后，铝/硅界面逐渐向铝侧迁移。这种界面原子迁移沿晶粒边界更为活跃，原因是晶粒的错位导致原子间的结合力减弱。新的界面呈现梯形，其特征是左侧面倾斜光滑，右侧面呈阶梯状。这种独特的形态可归因于界面能量的最小化。此外，迁移的硅原子倾向于按照铝的初始晶格取向形成新的纳米晶体，而扩散的铝原子通常是随机插入到硅晶格基体的一个大区域中，这可归因于铝的键能比硅低。本文受版权保护。
{"title":"In‐situ Observation of Atomic Diffusion at Epitaxial Al/Si Interface","authors":"Jinlin Wang, Qi Liu, Ran Feng, Haotian Ye, Xifan Xu, Rui Wang, Tao Wang, Xinqiang Wang","doi":"10.1002/pssr.202400175","DOIUrl":"https://doi.org/10.1002/pssr.202400175","url":null,"abstract":"High‐quality aluminum (Al) /silicon (Si) heterojunction is crucial in a wide range of applications, such as superconductivity, interfacial heat exchanging, interconnection of Si‐based transistors, etc. However, serious Al/Si heterointerface degradation has been observed when operating at relatively higher temperatures. Understanding the interfacial atomic diffusion is thus a vital step for improving the Al/Si interface quality. We report the atomic diffusion behavior at an epitaxial Al/Si interface via in‐situ heating in Cs‐corrected scanning transmission electron microscopy (STEM). After heating to 493 ± 20 K, the Al/Si interface gradually migrates towards the Al side. This interfacial atomic migration is more active along grain boundaries due to weaker bonding between atoms caused by misorientation of grains. The new interface exhibits a trapezoidal shape, characterized by a slanted smooth left facet and a stepped right facet. This distinct morphology is attributed to minimizing the interfacial energy. Additionally, the migrated Si atoms tend to form a new nanocrystal following the initial lattice orientation in Al, while the diffused Al atoms are usually randomly inserted into the Si lattice matrix among a large region, which can be attributed to lower bonding energy of Al compared with Si.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":"2024-06-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141529025","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}
A tunable material black phosphorus (BP) terahertz (THz) half‐ring Fano resonator is proposed, exhibiting enhanced sensitivity, tunable frequency parameters, and the flexible sensing range. A half‐ring is positioned above the main channel, while a groove is excavated beneath it to produce the Fano resonance. The discrete mode of the half‐ring is coupled with the continuous mode of the groove, leading to a significantly enhanced sensitivity. This sensor can pick up subtle changes in the surrounding environment. Additionally, the incorporation of BP into the half‐ring positioned above the channel enables the flexible adjustment of the Fano resonator's resonant frequency. This adjustment is achieved through the manipulation of the electron doping concentration of the BP material. At the third‐order resonance around 5.81 THz, the frequency shift margin can reach 160 GHz. Adjusting the structural parameters of the Fano resonator, such as the radius of its outer ring, the distance of this ring to the main channel, and the groove's height, significantly affects its transmission spectrum. The Fano resonator demonstrates its considerable potential for applications in the field of integrated electronics. It not only provides an innovative design perspective, but also lays the foundation for the study of THz systems.This article is protected by copyright. All rights reserved.
本文提出了一种可调谐材料黑磷（BP）太赫兹（THz）半环法诺谐振器，它具有更高的灵敏度、可调谐的频率参数和灵活的传感范围。半环位于主通道上方，在其下方开凿了一个凹槽，以产生法诺共振。半环的离散模式与凹槽的连续模式耦合，从而大大提高了灵敏度。这种传感器可以捕捉到周围环境的细微变化。此外，在通道上方的半环中加入 BP，可以灵活调节法诺谐振器的谐振频率。这种调整是通过操纵 BP 材料的电子掺杂浓度实现的。在 5.81 太赫兹左右的三阶共振频率下，频移余量可达 160 千兆赫。调整法诺谐振器的结构参数，如外环半径、外环到主通道的距离以及凹槽的高度，都会显著影响其传输频谱。法诺谐振器展示了其在集成电子领域的巨大应用潜力。它不仅提供了一个创新的设计视角，还为太赫兹系统的研究奠定了基础。本文受版权保护。
{"title":"Dynamically tunable half‐ring Fano resonator based on black phosphorus","authors":"Junyan Cheng, Weiliang Zeng, Wen Zhang, Yuanmei Xu, Kunhua Wen, Weijun Sun, Xiaozhao Fang, Yonghui Huang, Xue-Shi Li","doi":"10.1002/pssr.202400114","DOIUrl":"https://doi.org/10.1002/pssr.202400114","url":null,"abstract":"A tunable material black phosphorus (BP) terahertz (THz) half‐ring Fano resonator is proposed, exhibiting enhanced sensitivity, tunable frequency parameters, and the flexible sensing range. A half‐ring is positioned above the main channel, while a groove is excavated beneath it to produce the Fano resonance. The discrete mode of the half‐ring is coupled with the continuous mode of the groove, leading to a significantly enhanced sensitivity. This sensor can pick up subtle changes in the surrounding environment. Additionally, the incorporation of BP into the half‐ring positioned above the channel enables the flexible adjustment of the Fano resonator's resonant frequency. This adjustment is achieved through the manipulation of the electron doping concentration of the BP material. At the third‐order resonance around 5.81 THz, the frequency shift margin can reach 160 GHz. Adjusting the structural parameters of the Fano resonator, such as the radius of its outer ring, the distance of this ring to the main channel, and the groove's height, significantly affects its transmission spectrum. The Fano resonator demonstrates its considerable potential for applications in the field of integrated electronics. It not only provides an innovative design perspective, but also lays the foundation for the study of THz systems.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":"2024-06-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141518746","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}
As technology progresses, the operational frequencies of electronic devices have migrated into the GHz range. As an important electronic device, the compatibility of the preparation process of inductors with integrated circuits also needs to be improved. Currently, most commercial inductors are constructed from ferrite materials, making them challenging to integrate with integrated circuits. In this study, FeCoB films with a self‐biased ferromagnetic frequency up to 21 GHz were deposited on Si substrates using the compositional gradient sputtering method as a magnetic underlayer. A reasonable inductance structure is designed using HFSS simulation software. A series of planar spiral inductors with various turns were fabricated by photolithographic micromachining on the FeCoB films with a polyimide insertion between them. The preparation process is completely based on semiconductor technology and has good compatibility with integrated circuits. The results show that the inductance L and quality factor Q are greatly improved by the introduction of high‐frequency FeCoB film. The inductance is improved by 71% and the quality factor is improved by 166%. This clearly demonstrates that FeCoB thin films are highly suitable for use as inductor cores and can be seamlessly integrated with integrated circuits, offering excellent prospects for use in high‐frequency integrated circuits.This article is protected by copyright. All rights reserved.
{"title":"Inductance and Q‐factor of micro‐magnetic inductor are enhanced by FeCoB films with self‐bias","authors":"Chao Sun, Dalong Qiu, Peng Li, Zhao Yao, Weihua Zong, Shandong Li","doi":"10.1002/pssr.202400167","DOIUrl":"https://doi.org/10.1002/pssr.202400167","url":null,"abstract":"As technology progresses, the operational frequencies of electronic devices have migrated into the GHz range. As an important electronic device, the compatibility of the preparation process of inductors with integrated circuits also needs to be improved. Currently, most commercial inductors are constructed from ferrite materials, making them challenging to integrate with integrated circuits. In this study, FeCoB films with a self‐biased ferromagnetic frequency up to 21 GHz were deposited on Si substrates using the compositional gradient sputtering method as a magnetic underlayer. A reasonable inductance structure is designed using HFSS simulation software. A series of planar spiral inductors with various turns were fabricated by photolithographic micromachining on the FeCoB films with a polyimide insertion between them. The preparation process is completely based on semiconductor technology and has good compatibility with integrated circuits. The results show that the inductance L and quality factor Q are greatly improved by the introduction of high‐frequency FeCoB film. The inductance is improved by 71% and the quality factor is improved by 166%. This clearly demonstrates that FeCoB thin films are highly suitable for use as inductor cores and can be seamlessly integrated with integrated circuits, offering excellent prospects for use in high‐frequency integrated circuits.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":"2024-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141518747","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}
Junhui Wang, Xiang Li, Youyi Ding, Lan Zhang, Haijun Zhao, Yidan Hu, Wei Du, Tao Wang
Phonon polaritons (PhPs) in hexagonal boron nitride enable sharp mid‐infrared optical resonance with strong spatial confinement, making them promising for surface enhanced infrared absorption spectroscopy. Here, using colloidal nanosphere lithography, we have fabricated hBN nanopillar antennas and demonstrated their PhP resonances in a cost‐effective way. By varying the diameters of the hBN nanopillars, the PhP resonance can be readily tuned to match the molecular vibrations of CBP (4,4′‐bis(N‐carbazolyl)‐1,1′‐biphenyl) molecules. Upon frequency matching, the coupling between the PhP resonance and the molecular vibration shows pronounced mode splitting, illustrating the SEIRA behaviour with a coupling strength approaching the strong coupling regime. While, with slight frequency mismatching around 10 cm‐1, the coupling strength decrease significantly, indicating a high sensitivity of the SEIRA activities to the resonance frequency of hBN nanopillar antennas. Our findings provide a new method for the fabrication of PhP nanoantennas and may promote the development of PhPs in SEIRA‐based mid‐infrared sensing applications.This article is protected by copyright. All rights reserved.
{"title":"Phonon‐polaritonic resonances on nanopillars of hexagonal boron nitride for surface enhanced infrared absorption","authors":"Junhui Wang, Xiang Li, Youyi Ding, Lan Zhang, Haijun Zhao, Yidan Hu, Wei Du, Tao Wang","doi":"10.1002/pssr.202400163","DOIUrl":"https://doi.org/10.1002/pssr.202400163","url":null,"abstract":"Phonon polaritons (PhPs) in hexagonal boron nitride enable sharp mid‐infrared optical resonance with strong spatial confinement, making them promising for surface enhanced infrared absorption spectroscopy. Here, using colloidal nanosphere lithography, we have fabricated hBN nanopillar antennas and demonstrated their PhP resonances in a cost‐effective way. By varying the diameters of the hBN nanopillars, the PhP resonance can be readily tuned to match the molecular vibrations of CBP (4,4′‐bis(N‐carbazolyl)‐1,1′‐biphenyl) molecules. Upon frequency matching, the coupling between the PhP resonance and the molecular vibration shows pronounced mode splitting, illustrating the SEIRA behaviour with a coupling strength approaching the strong coupling regime. While, with slight frequency mismatching around 10 cm<jats:sup>‐1</jats:sup>, the coupling strength decrease significantly, indicating a high sensitivity of the SEIRA activities to the resonance frequency of hBN nanopillar antennas. Our findings provide a new method for the fabrication of PhP nanoantennas and may promote the development of PhPs in SEIRA‐based mid‐infrared sensing applications.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":"2024-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141518748","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}
Quasi‐vertical GaN trench‐gate MOSFETs with different etch RF power and the impact of the order of annealing process in TMAH wet treatment have been fabricated and studied. The high‐power device has a threshold voltage of 5.3 V and a maximum saturation current density of 552 A/cm2, whereas the low‐power device has a threshold voltage of 4.5 V and a maximum saturation current density of 650 A/cm2. However, the low‐power device has more severe off‐state leakage due to more fixed charges and defects on the device surface. Furthermore, the annealing process serves as an additional step before wet treatment. SEM image indicates that annealing at high temperatures prior to etching can eliminate surface oxide and redistribute surface imperfections, resulting in a smoother sidewall morphology. The relationship between temperature and mobility confirms the impact of the crystal surface feature on device performance.This article is protected by copyright. All rights reserved.
{"title":"Annealing Process on MOS channel Properties for Quasi‐Vertical GaN‐on‐Sapphire Trench MOSFET","authors":"Jiaan Zhou, An Yang, Guohao Yu, Runxian Xing, Bohan Guo, Chunfeng Hao, Yu Li, Bosen Liu, Huixin Yue, Jinxia Jiang, Li Zhang, Xuguang Deng, Zhongming Zeng, Baoshun Zhang, Xinping Zhang","doi":"10.1002/pssr.202400075","DOIUrl":"https://doi.org/10.1002/pssr.202400075","url":null,"abstract":"Quasi‐vertical GaN trench‐gate MOSFETs with different etch RF power and the impact of the order of annealing process in TMAH wet treatment have been fabricated and studied. The high‐power device has a threshold voltage of 5.3 V and a maximum saturation current density of 552 A/cm<jats:sup>2</jats:sup>, whereas the low‐power device has a threshold voltage of 4.5 V and a maximum saturation current density of 650 A/cm<jats:sup>2</jats:sup>. However, the low‐power device has more severe off‐state leakage due to more fixed charges and defects on the device surface. Furthermore, the annealing process serves as an additional step before wet treatment. SEM image indicates that annealing at high temperatures prior to etching can eliminate surface oxide and redistribute surface imperfections, resulting in a smoother sidewall morphology. The relationship between temperature and mobility confirms the impact of the crystal surface feature on device performance.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":"2024-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141191841","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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