{"title":"Forward bias stress-induced degradation mechanism in β-Ga2O3 SBDs: A trap-centric perspective","authors":"Sijie Bu, Yingzhe Wang, Xuefeng Zheng, Shaozhong Yue, Danmei Lin, Longbing Yi, Vazgen Melikyan, Xiaohua Ma, Yue Hao","doi":"10.1063/5.0260529","DOIUrl":"https://doi.org/10.1063/5.0260529","url":null,"abstract":"This study explores the impact of constant forward electrical stress on beta-gallium oxide (β-Ga2O3) Schottky barrier diodes (SBDs) from the prospective of defect evolution. Prolonged stress significantly increased the reverse leakage current density (JR) and forward current density (JF) under small bias and decreased the turn-on voltage (Von). Temperature-dependent current-voltage (I-V-T) analysis revealed that the reverse leakage current is dominated by Poole-Frenkel (PF) emission in both fresh and stressed SBDs, while the forward current transport mechanism transforms from thermionic emission (TE) to trap-assisted tunneling (TAT) after stress. Deep-level transient spectroscopy (DLTS) results identified an intrinsic trap E2* (EC - 0.75 eV) within the β-Ga2O3 drift layer, which is likely a Ga vacancy-related trap. The consistency of this energy level with the PF barrier proves that the increase in this trap is the main reason for the increase in JR. The spatial distribution features that the increase in trap concentration near the metal-semiconductor interface is much larger than that inside the bulk, which establishes the association between this trap and JF under small bias and Von. These findings highlight the critical role of trap evolution in SBD performance degradation under electrical stress.","PeriodicalId":8094,"journal":{"name":"Applied Physics Letters","volume":"90 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143703409","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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}
Ruishan Tan, Yunpeng Yang, Zesen Lei, Cuiru Sun, Yuanpeng Ma, Dongna Feng, Tao Jing, Qilong Sun
{"title":"Controllable ferromagnetism in Cr2Te2 monolayer with intrinsic half-metallicity","authors":"Ruishan Tan, Yunpeng Yang, Zesen Lei, Cuiru Sun, Yuanpeng Ma, Dongna Feng, Tao Jing, Qilong Sun","doi":"10.1063/5.0253343","DOIUrl":"https://doi.org/10.1063/5.0253343","url":null,"abstract":"Two-dimensional (2D) magnetic materials with high spin polarization and controllable magnetic anisotropy energy (MAE) are critical for advancing spintronic technologies. Using first-principles calculations, we demonstrate that monolayer Cr2Te2 exhibits intrinsic dynamic/thermal stability, half-metallicity, and robust ferromagnetic ordering. The Curie temperature (Tc) can be elevated from 90 to 190 K via external stimuli. Strain engineering, carrier doping, and electric-fields enable precise control of MAE, while tensile strain and electron doping enhance MAE to 2.680 meV. Conversely, compressive strain and hole doping induce a spin reorientation transition. Moreover, external electric fields also play a key role in determining MAE, suggesting a promising strategy for manipulating MAE in 2D ferromagnets. These modifications primarily arise from the alternations of the spin–orbit coupling (SOC) strength between Te-derived p-orbitals within specific spin channels. These findings establish Cr2Te2 as a versatile platform for spintronics integrating half-metallicity with dynamically adjustable magnetic properties and motivate further experimental exploration.","PeriodicalId":8094,"journal":{"name":"Applied Physics Letters","volume":"76 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143703560","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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}
Yu Tang, Junjie Li, Yang Cheng, Zhengqi Liu, Xiaoshan Liu, Guolan Fu, Hanyang Gong, Pingping Pan, Guiqiang Liu
{"title":"Temperature-controlled terahertz chirality and imaging in a nested split-rings metasurface","authors":"Yu Tang, Junjie Li, Yang Cheng, Zhengqi Liu, Xiaoshan Liu, Guolan Fu, Hanyang Gong, Pingping Pan, Guiqiang Liu","doi":"10.1063/5.0250905","DOIUrl":"https://doi.org/10.1063/5.0250905","url":null,"abstract":"Chiral metasurfaces exhibit vast application prospects in near-field imaging, polarization conversion, and chiral sensing. In this work, we theoretically propose a temperature-tunable terahertz (THz) chiral absorber based on a metasurface of Ag–VO2 nested split-rings. Perfect absorption of left-handed circularly polarized light (LCP) exceeding 99% and weak absorption of only about 6% of right-handed circularly polarized light (RCP) are achieved at 7.24 THz in frequency. The discrepancy in absorption responses of LCP and RCP results in a large circular dichroism (CD) of 0.94. The CD value in the THz region can be actively modulated between 0.02 and 0.94 by controlling the phase transition of VO2, which is closely related to the ambient temperature. Moreover, near-field imaging and encrypted presentation are realized by leveraging the metasurface and its mirror-image properties. Our work holds significant promise in widespread fields including THz intelligent absorption, imaging, and chiral detection.","PeriodicalId":8094,"journal":{"name":"Applied Physics Letters","volume":"12 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143703567","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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}
Seohyeon Park, Jaewook Yoo, Minah Park, Hongseung Lee, Hyeonjun Song, Seongbin Lim, Soyeon Kim, Sojin Jung, TaeWan Kim, Yang-Kyu Choi, Hagyoul Bae
{"title":"Determination of donor- and acceptor-like interface trap density using photoresponsive GIDL in vertically stacked Si-NW GAA FETs","authors":"Seohyeon Park, Jaewook Yoo, Minah Park, Hongseung Lee, Hyeonjun Song, Seongbin Lim, Soyeon Kim, Sojin Jung, TaeWan Kim, Yang-Kyu Choi, Hagyoul Bae","doi":"10.1063/5.0254522","DOIUrl":"https://doi.org/10.1063/5.0254522","url":null,"abstract":"This work reports an effective technique that is proposed for the simultaneous extraction of the energy distribution of donor- and acceptor-like interface trap states [Dit,D(E) and Dit,A(E)] over a wide range of bandgap energies using a single current–voltage (I–V) measurement in vertically stacked silicon nanowire (Si-NW) gate-all-around field-effect transistors. In the proposed method, we analyzed Dit,D(E) and Dit,A(E) based on the trap-induced photoresponsive gate-induced drain leakage with sub-bandgap optical source (Eph = hν < Eg) at VGS ≪ VFB and differential body factor technique in the subthreshold current at VFB < VGS < VT, respectively.","PeriodicalId":8094,"journal":{"name":"Applied Physics Letters","volume":"57 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143703592","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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}
Zhou Cui, Xunkai Duan, Jiansen Wen, Ziye Zhu, Jiayong Zhang, Jiajie Pei, Cuilian Wen, Tong Zhou, Bo Wu, Baisheng Sa
{"title":"Ferroelectric control of valleytronic nonvolatile storage in HfCl2/Sc2CO2 heterostructure","authors":"Zhou Cui, Xunkai Duan, Jiansen Wen, Ziye Zhu, Jiayong Zhang, Jiajie Pei, Cuilian Wen, Tong Zhou, Bo Wu, Baisheng Sa","doi":"10.1063/5.0264472","DOIUrl":"https://doi.org/10.1063/5.0264472","url":null,"abstract":"Valleytronics, utilizing the valley degree of freedom in electrons, has potential for advancing the next-generation nonvolatile storage. However, practical implementation remains challenging due to the limited control over valleytronic properties. Here, we propose ferroelectric HfCl2/Sc2CO2 van der Waals heterostructure as a platform to overcome these limitations, enabling tunable and nonvolatile valleytronic behaviors. Our findings show that the electric polarization state of the Sc2CO2 monolayer governs the electronic properties of heterostructures. Positive polarization induces a direct gap at the valleys, enabling valleytronic functionality for excitation and readout via circularly polarized light, while negative polarization results in an indirect-gap, suppressing valleytronic behavior. Moreover, our transport simulations further demonstrate a polarization-dependent ferroelectric p-i-n junction with 8 nm possesses a maximum tunnel electroresistance (TER) ratio of 1.60 × 108% at a bias of 0.5 eV. These results provide insights into ferroelectric-controlled valleytronic transitions and position the HfCl2/Sc2CO2 heterostructure as a promising candidate for energy-efficient valleytronic memory and nonvolatile storage applications.","PeriodicalId":8094,"journal":{"name":"Applied Physics Letters","volume":"21 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143703573","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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}
Yujiao Cao, Jie Wei, Xiaogeng Huo, Youchun Wang, Ketao Yin
{"title":"High-pressure polyhedral interaction in CsSnI3","authors":"Yujiao Cao, Jie Wei, Xiaogeng Huo, Youchun Wang, Ketao Yin","doi":"10.1063/5.0257590","DOIUrl":"https://doi.org/10.1063/5.0257590","url":null,"abstract":"In recent years, metal halide perovskites have attracted great interest in various applications because of their excellent properties. Here, we find pressure-induced transformations of edge-sharing Sn−I polyhedra to face-sharing Sn−I polyhedra and subsequently to quasi-two-dimensional layer Sn–I polyhedra in CsSnI3 semiconductor phases at 5.4 and 40 GPa. Our first-principles density functional theory calculations uncover that the phase transformation is due to the variation of Sn atomic coordination accompanied by the Sn–I polyhedral distortion. Both phases are indirect bandgap, which is smaller than the atmospheric phase. Further calculations show that intrapolyhedral Sn−Sn hybridization and interpolyhedral I–I coupling lead to the Sn–I polyhedral distortion. These findings will provide valuable insights into phase transformation of perovskites at high pressures.","PeriodicalId":8094,"journal":{"name":"Applied Physics Letters","volume":"198 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143703572","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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}
{"title":"Understanding the microstructure effects of graphite electrode in lithium-ion batteries through multi-physics simulation","authors":"Wen Luo, Jin-Ying Jiao, Jian Wang, Yu-Lin Duan, Zhong-Hui Shen","doi":"10.1063/5.0257063","DOIUrl":"https://doi.org/10.1063/5.0257063","url":null,"abstract":"Graphite anodes are widely regarded as key components for achieving high-performance lithium-ion batteries. However, research on the multiscale effects of anode microstructures remains lacking in depth. The influence of transport and reaction processes within the microstructure on overall battery performance requires a coupling investigation integrating both electrochemical and physical field data. In this study, we construct a two-dimensional (2D) multi-physics model and simulate the 2D geometry and internal electrochemical processes to investigate the multiscale effects of microstructures on overall battery performance. Concurrently, we design three distinct anode structures: porosity gradient distribution structures, hard carbon–graphite composite anodes, and hard carbon-coated graphite anodes to identify structural features that enhance key battery performance metrics. Additionally, we analyze the distribution of side-reaction products and the Li+ concentration to reveal the influence of different microstructures on internal mass transport and electrochemical reactions. We also identify the factors within these three structures that contribute to extending battery lifespan and improving overall performance. This work systematically establishes the relationship between anode microstructures and battery performance, providing insights that are expected to optimize materials, reduce trial-and-error, and use simulations to guide experimental work more efficiently.","PeriodicalId":8094,"journal":{"name":"Applied Physics Letters","volume":"25 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143703574","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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}
Kishore K. Madapu, C. Abinash Bhuyan, Sandip Dhara
{"title":"Probing near-field heating effects on monolayer MoS2 photoluminescence via tip-enhanced Raman spectroscopy","authors":"Kishore K. Madapu, C. Abinash Bhuyan, Sandip Dhara","doi":"10.1063/5.0250931","DOIUrl":"https://doi.org/10.1063/5.0250931","url":null,"abstract":"The photoluminescence (PL) intensity of monolayer MoS2 is limited by weak optical absorption due to its atomic scale thickness. To enhance PL intensity, field enhancement techniques, such as surface plasmon resonance (SPR) of metal nanoparticles, are often employed. However, SPR-induced light confinement at the nanoscale also leads to significant localized heating. In this study, we investigated the impact of near-field heating due to SPR using tip-enhanced Raman spectroscopy (TERS) and tip-enhanced photoluminescence studies. Our results reveal nearly an order-of-magnitude difference in the enhancement factors (EFs) for Raman and PL signals of monolayer MoS2, with a local temperature increase of approximately 147 °C under the TERS tip at a laser power of 10.57 mW. The reduced PL EF compared with Raman EF is attributed to additional near-field heating from SPR. We further observed that local temperature fluctuations critically affect the EFs and found that a high thermal conductivity substrate can effectively mitigate the near-field thermal effects associated with SPR.","PeriodicalId":8094,"journal":{"name":"Applied Physics Letters","volume":"35 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143703565","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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}
{"title":"Hot-carrier photocatalysts with energy-selective contacts based on quantum wells and dots","authors":"Shuanglong Han, Zhiqiang Fan, Ousi Pan, Xiaohang Chen, Zhimin Yang, Yanchao Zhang, Jincan Chen, Shanhe Su","doi":"10.1063/5.0256536","DOIUrl":"https://doi.org/10.1063/5.0256536","url":null,"abstract":"Two types of hot-carrier photocatalysts (HCPCs) based on quantum well and quantum dot energy-selective contacts (ESCs) have been proposed. The transport equations for both types of devices are derived using the ballistic transport theory. The electrocatalytic behavior of reaction sites in water splitting is modeled by using the Butler–Volmer equation. The impacts of the ESC parameters, including the extraction energy level and the transmission energy width, on the performance of HCPC devices have been investigated. The results indicate that the thermal losses from non-ideal ESCs significantly limit HCPC efficiency, which can be enhanced by optimizing ESC parameters. Comparisons show that HCPCs with quantum dot ESCs outperform those with quantum well ESCs, owing to their superior carrier transport capability and lower thermal loss rates. For an absorber bandgap of 1 eV, the optimized solar-to-H2 energy conversion efficiencies of the two HCPCs reach 62.34% and 64.93%, respectively, highlighting the promising application potential of these catalysts.","PeriodicalId":8094,"journal":{"name":"Applied Physics Letters","volume":"57 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143703561","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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}
Mo Yang, Zihang Song, Fangrong Hu, Dawei Wei, Zifeng Yang
{"title":"Ultra-broadband terahertz polarization converter based on flexible metamaterial","authors":"Mo Yang, Zihang Song, Fangrong Hu, Dawei Wei, Zifeng Yang","doi":"10.1063/5.0259523","DOIUrl":"https://doi.org/10.1063/5.0259523","url":null,"abstract":"Polarization is one of the basic properties of electromagnetic (EM) waves, and polarization conversion is essential in many terahertz (THz) applications, including communications and sensitive measurements. Due to the limitations of the materials and process, existing THz polarization converters generally have the disadvantages of narrow operating frequency band and non-flexibility. We experimentally demonstrate a flexible ultra-broadband THz polarization converter operating in reflection. It can efficiently convert a linearly polarized THz wave to its orthogonal counterpart in a broadband regime. The device consists of three layers: the lower metal film, the middle dielectric layer, and the upper metal resonance structure array. The unit cell of the upper metal resonance structure is a four-open-ring formed by subtracting two metal bars from a metal ring. The position of the opening is in the diagonal direction of 45° from the upper right corner to the lower left corner of the unit structure. The device is simulated using a full wave EM simulation software and fabricated by a surface micromachining process. The test experiment is completed using a THz-TDS spectrometer and the results show that the polarization conversion ratio is more than 0.8 in an ultra-broadband regime from 1.45 to 2.67 THz. This ultra-broadband conversion is mainly caused by the magnetic resonance of THz waves. More importantly, the convertible frequency band can be tailored for practical applications across the EM spectrum.","PeriodicalId":8094,"journal":{"name":"Applied Physics Letters","volume":"92 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143703570","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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}