Journal of Physics D最新文献_第3页

Electrical resistivity mapping of potassium-doped few-layer CVD graphene by EBAC measurements 用EBAC测量方法绘制掺钾少层CVD石墨烯的电阻率图

Journal of Physics D Pub Date : 2023-11-08 DOI: 10.1088/1361-6463/ad0aee

Yuki Okigawa, Hideaki Nakajima, Toshiya Okazaki, Takatoshi Yamada

{"title":"Electrical resistivity mapping of potassium-doped few-layer CVD graphene by EBAC measurements","authors":"Yuki Okigawa, Hideaki Nakajima, Toshiya Okazaki, Takatoshi Yamada","doi":"10.1088/1361-6463/ad0aee","DOIUrl":"https://doi.org/10.1088/1361-6463/ad0aee","url":null,"abstract":"Abstract The electron beam absorbed current (EBAC) method identifies the open and/or short points in various semiconductor devices, which can be applied to characterize the current path and local resistance in graphene. In this study, potassium (K)-doped few-layer graphene with inhomogeneous K atoms seemed to be one of the appropriate materials to characterize the current path by EBAC. Nonuniform contrast in the EBAC image due to inhomogeneous local resistances is observed, which is explained by the variation of the Fermi level in the graphene channel from the G-band peak shifts from Raman spectroscopy. The changes in the contrast of the EBAC images are obtained by applying a gate voltage. These changes are attributed to the modulation of the local carrier densities by applying the gate voltage. For comparison, uniform contrast in EBAC images and uniform G-band peak positions of undoped few-layer graphene FETs are confirmed. The obtained results suggest that homogeneous Fermi level leads to uniform current path. EBAC enables us to evaluate the uniformity of local resistance and current through a pass in the graphene channel, which can be applied to other two-dimensional materials, such as transition metal dichalcogenides, graphene oxide and h -BN.","PeriodicalId":16833,"journal":{"name":"Journal of Physics D","volume":" 9","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135340948","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}

引用次数: 0

Electromagnetically induced transparency in a strongly coupled orthogonal polarization insensitive planar terahertz metamaterial 强耦合正交极化不敏感平面太赫兹超材料的电磁感应透明

Journal of Physics D Pub Date : 2023-11-08 DOI: 10.1088/1361-6463/ad0aed

Lavi Kumar vaswani, Bhagwat Singh Chouhan, Anuraj Panwar, Gagan Kumar

引用次数: 0

Enhanced performance of AlGaN-based deep-UV LED by incorporating carrier injection balanced modulation layer synergistically with polarization-regulating structures 利用载流子注入平衡调制层与偏振调节结构协同作用，提高了algan基深紫外LED的性能

Journal of Physics D Pub Date : 2023-11-08 DOI: 10.1088/1361-6463/ad0ac1

Xun Hu, Lijing Kong, Pan Yang, Na Gao, Huang Kai, Shuping Li, Junyong Kang, Rong Zhang

{"title":"Enhanced performance of AlGaN-based deep-UV LED by incorporating carrier injection balanced modulation layer synergistically with polarization-regulating structures","authors":"Xun Hu, Lijing Kong, Pan Yang, Na Gao, Huang Kai, Shuping Li, Junyong Kang, Rong Zhang","doi":"10.1088/1361-6463/ad0ac1","DOIUrl":"https://doi.org/10.1088/1361-6463/ad0ac1","url":null,"abstract":"Abstract A comparable concentration of carriers injected and transported into the active region, that is, balanced hole and electron injection, significantly affects the optoelectronic performance of AlGaN-based deep ultraviolet light emitting diodes (DUV LEDs). In this study,-we introduce a novel structure characterized by a carrier injection balanced modulation layer, incorporating a polarization-regulating gradient p-AlGaN in a DUV LED. We conducted a systematic examination of its impact on the carrier injection and transport processes.&#xD;Theoretical simulations demonstrate the mitigation of abrupt variations in Al content at the interface between EBL/p-AlGaN and p-AlGaN/p-GaN within the valence bands. Consequently, holes are more likely to be injected into the active region rather than accumulating at these interfaces. Meanwhile, due to the reduced barrier height at the top of the valence band, the holes were efficiently transported into the quantum well and confined with comparable and balanced concentrations of electrons by suppressing overflow, thereby promoting the radiative recombination rate. Compared with the conventional DUV LED, the hole concentration and radiative recombination rate of the designed structure in the final quantum well are significantly increased to 179.8% and 232.3%, respectively. The spontaneous emission intensity achieves nearly twice at the same current injection density. Moreover, the efficiency droop is significantly suppressed when operated at a gradually increasing current density. This study presents a promising approach that can serve as a reference for achieving high-efficiency AlGaN-based DUV LEDs.&#xD;","PeriodicalId":16833,"journal":{"name":"Journal of Physics D","volume":" 39","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135341410","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}

引用次数: 0

Deconstructing Plasma Fog Collection Technology: An Experimental Study on Factors Impacting Collection Efficiency 解构等离子体雾收集技术:影响收集效率因素的实验研究

Journal of Physics D Pub Date : 2023-11-08 DOI: 10.1088/1361-6463/ad0ac2

Dingchen Li, Chuan Li, Menghan Xiao, Li Jiawei, Zhiwen Yang, Qixiong Fu, Ming Zhang, Kexun Yu, Yuan Pan

{"title":"Deconstructing Plasma Fog Collection Technology: An Experimental Study on Factors Impacting Collection Efficiency","authors":"Dingchen Li, Chuan Li, Menghan Xiao, Li Jiawei, Zhiwen Yang, Qixiong Fu, Ming Zhang, Kexun Yu, Yuan Pan","doi":"10.1088/1361-6463/ad0ac2","DOIUrl":"https://doi.org/10.1088/1361-6463/ad0ac2","url":null,"abstract":"Abstract Water scarcity is a global challenge that hinders human development. In recent years, electrostatic fog collection technology has emerged as a promising technology to alleviate this issue. Although electrostatic fog collectors based on a variety of electrode structures have been developed previously, there has been less research into other factors affecting the efficiency of electrostatic fog collection (e.g. electrical factors, environmental factors, etc.), which has delayed the commercial application of the technology. In this paper, we experimentally investigate the effects of power supply polarity, voltage, airflow direction, airflow velocity, fog concentration and temperature on collection efficiency using a typical wire-mesh electrode fog collector as an example. The results show that both electrical and environmental factors influence the collection efficiency by changing the charge and the electric field force of the droplets. Negative polarity corona and high voltage are more favorable for fog collection. High velocity airflow and high fog concentration increase the amount of water collected due to the ability to bring more droplets into the electric field. However, the collection efficiency is reduced by the weakening of the corona discharge. High temperature accelerates the evaporation of fog droplets, which is not favorable for fog collection. In conclusion, this work will not only contribute to revealing the underlying mechanisms of the electrostatic fog collection but also will guide the development of highly efficient fog collectors.","PeriodicalId":16833,"journal":{"name":"Journal of Physics D","volume":" 10","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135341265","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}

引用次数: 0

Red photostimulated luminescence and afterglow in CaS:Eu^2+,Mn²⁺ phosphors CaS:Eu2+，Mn2+荧光粉中的红色光激发发光和余辉

Journal of Physics D Pub Date : 2023-11-08 DOI: 10.1088/1361-6463/ad0ac0

Kazuaki Iguchi, Yuta Nishigawa, Yoriko Suda, Yasushi Nanai, Tsuyoshi Okuno

引用次数: 0

Phase formation and electrical properties of reactively sputtered Fe_1-xO thin films 反应溅射Fe1-xO薄膜的相形成和电学性能

Journal of Physics D Pub Date : 2023-11-07 DOI: 10.1088/1361-6463/ad0a3e

Simon Evertz, Nina Nicolin, Ningyan Cheng, Daniel Primetzhofer, James P. Best, Gerhard Dehm

{"title":"Phase formation and electrical properties of reactively sputtered Fe1-xO thin films","authors":"Simon Evertz, Nina Nicolin, Ningyan Cheng, Daniel Primetzhofer, James P. Best, Gerhard Dehm","doi":"10.1088/1361-6463/ad0a3e","DOIUrl":"https://doi.org/10.1088/1361-6463/ad0a3e","url":null,"abstract":"Abstract Wüstite, Fe 1-x O, is a crucial phase for the transition to CO 2 -free steel manufacturing as well as promising for electrochemical applications such as water splitting and ammonia synthesis. To study the effect of interfaces in these applications, thin-film model systems with defined interfaces are ideal. Previous studies lack a description of the growth mechanism to obtain Fe 1-x O thin films. Here, we investigate the phase formation of metastable Fe 1-x O during reactive magnetron sputtering while systematically varying the O 2 /Ar flow ratio from 1.8 to 7.2% and the pressure-distance product between 3.5 and 7.2 Pa∙cm. If bulk diffusion is minimized, thin films containing 96 vol.% wüstite and 4 vol.% Fe as impurity phase were achieved. Therefore, the formation of the wüstite phase appears to be surface diffusion dominated. To reveal the influence of impurity phases in wüstite on the electrical resistivity, systematic electrical resistivity measurements while cooling in situ were performed for the first time. The electrical resistivity was lower than that of single crystals of the respective iron oxides. This is attributed to the formation of Fe-rich layers at the substrate-film interface, which serve as additional conduction paths.&#xD;","PeriodicalId":16833,"journal":{"name":"Journal of Physics D","volume":"7 4","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135480175","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}

引用次数: 0

Ultra-wideband chiroptical response by tri-layer anisotropic plasmonic metamaterial 三层各向异性等离子体超材料的超宽带热力响应

Journal of Physics D Pub Date : 2023-11-06 DOI: 10.1088/1361-6463/ad066d

Shahid Hussain, Xueyu Guan, Ruonan Ji, Shao-Wei Wang

{"title":"Ultra-wideband chiroptical response by tri-layer anisotropic plasmonic metamaterial","authors":"Shahid Hussain, Xueyu Guan, Ruonan Ji, Shao-Wei Wang","doi":"10.1088/1361-6463/ad066d","DOIUrl":"https://doi.org/10.1088/1361-6463/ad066d","url":null,"abstract":"Abstract The use of plasmonic chiral metamaterials for the control of circular polarization has the potential to replace conventional optical equipment for polarization-related applications. The ultra-broadband chiroptic response using plasmonic constituents is delivered by elaborate three-dimensional (3D) helical structures, nevertheless, their implementation is complicated, time-consuming, and poses a significant scaling difficulty at the nano level. Ultra-broadband response from planar constituents is particularly necessary as a means to circumvent the challenges of 3D metamaterials. Here we present a planar plasmonic structure composed of tri-layer anisotropic arrays constituting nanowires and cut-wires to generate dual overlapped chiral bands. Based on this tri-layer approach, we numerically realized ultra-broadband planar plasmonic metamaterials to function in the near- and mid-infrared regions with a bandwidth range of 1.38–3.07 µ m and 4.00–8.10 µ m, and maximum circular dichroism performance of 0.90 and 0.92 respectively. The structures are ultracompact, misalignments tolerant, and can be extended to additional spectral regions through structural engineering. The proposed metamaterial has the potential to be used in the creation of ultra-compact, high-performance devices for a wide variety of uses, such as those in the fields of optical communication, biological diagnosis, high-contrast polarization imaging, high-accuracy polarimetric measurements, and spectroscopy.","PeriodicalId":16833,"journal":{"name":"Journal of Physics D","volume":"105 6","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135584882","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}

引用次数: 0

Dosimetric characterization of double network Fricke hydrogel based on PVA-GTA and phenylalanine peptide derivative 基于PVA-GTA和苯丙氨酸肽衍生物的双网络Fricke水凝胶的剂量学表征

Journal of Physics D Pub Date : 2023-11-03 DOI: 10.1088/1361-6463/ad0987

Salvatore Gallo, Silvia Locarno, Elisa Brambilla, Cristina Lenardi, Emanuele Pignoli, Ivan Veronese

{"title":"Dosimetric characterization of double network Fricke hydrogel based on PVA-GTA and phenylalanine peptide derivative","authors":"Salvatore Gallo, Silvia Locarno, Elisa Brambilla, Cristina Lenardi, Emanuele Pignoli, Ivan Veronese","doi":"10.1088/1361-6463/ad0987","DOIUrl":"https://doi.org/10.1088/1361-6463/ad0987","url":null,"abstract":"Abstract A double network hydrogel based on Poly(vinyl-alcohol) (PVA) cross-linked with Glutaraldehyde (GTA) was recently developed by using self-assembling phenylalanine (Phe) peptide derivative (Fmoc-Phe-Phe-OMe), with the aim to improve the mechanical-elastic properties of PVA-GTA hydrogels. In this study, a characterization of the properties of Xylenol Orange based Fricke gel dosimeters obtained by infusing a Fricke solution into the double network hydrogel was performed. The gel dosimeters were irradiated with 6 MV and 15 MV X-rays produced by a medical linear accelerator and investigated by means optical absorbance measurements. &#xD;The double network hydrogel formulation maintained a satisfactory level of radiological water-equivalence within the investigated radiotherapy range. Fricke gel dosimeters prepared with such network kept the desired properties of independence of the response of the dose rate and energy in the investigated intervals. Furthermore, the addition of self-assembling Phe peptide derivative proved not avoid the motion of radio-inducted ferric ions into the hydrogel, probably maintaining the main characteristics of the standard, no Phe peptide infused, formulation. The time course of formation of the optical response after the irradiation was observed to be similar to what previously measured in traditional PVA-GTA Fricke gel dosimeters, while a decrease of the sensitivity to radiation dose of the order of 30% was found. The extent of the decrease does not seem such as to impair the use of these dosimeters for evaluation of doses typical of radiation therapy applications. &#xD;The overall dosimetric properties, coupled with the mechanical-elastic characteristics of the double network hydrogel, pave the way to the development of phantoms able both to mimic the deformation of organs possibly occurring during radiotherapy treatments and at the same time to assess the 3D dose distribution within such volumes.","PeriodicalId":16833,"journal":{"name":"Journal of Physics D","volume":"105 4","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135819076","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}

引用次数: 0

Effect of growth parameters on conducting Ca_xTa_yO_3-δ/SrTiO₃ interface 生长参数对CaxTayO3-δ/SrTiO3界面导电性能的影响

Journal of Physics D Pub Date : 2023-11-03 DOI: 10.1088/1361-6463/acfcc5

Sumit Kumar, Simran Nehra, Shikha Shrivastava, A. Rathi, Kamlesh Kumar Maurya, Sunil Ojha, Sonu Chhillar, C. S. Yadav, Vipin Chawla, Anjana Dogra

{"title":"Effect of growth parameters on conducting CaxTayO3-δ/SrTiO3 interface","authors":"Sumit Kumar, Simran Nehra, Shikha Shrivastava, A. Rathi, Kamlesh Kumar Maurya, Sunil Ojha, Sonu Chhillar, C. S. Yadav, Vipin Chawla, Anjana Dogra","doi":"10.1088/1361-6463/acfcc5","DOIUrl":"https://doi.org/10.1088/1361-6463/acfcc5","url":null,"abstract":"Abstract In search of novel conducting oxide heterointerfaces, we previously uncovered an distinctive quasi two-dimensional electron gas (q-2DEG) type behaviour in non-stoichimetric Ca x Ta y O 3-δ /SrTiO 3 heterostructure. However, the underlying mechanism remained enigmatic. In this study, we delve into the intricate interplay of growth conditions, stoichiometry, and transport properties of these heterostructures. Using (Ca 0.5 TaO 3 ) 2 Target and the pulsed laser deposition technique, we grow the epitaxial thin films while systematically varying growth parameters, inculding laser energy density, oxygen pressures, and post-deposition annealing. Structural analysis unveiled a notable presence of oxygen vacancies in the as-grown films, while annealed samples exhibited an oxygen surplus. Building upon these findings, our comprehensive charge transport measurements revealed that while oxygen vacancies do contribute to conductivity, the polar catastrophe model takes precedence as the primary source of interfacial conductance in these heterostructures. This study provides valueable insights into the behavior of these innovative heterostructures, paving the way for future advancements in the field.","PeriodicalId":16833,"journal":{"name":"Journal of Physics D","volume":"182 S476","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135775737","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}

引用次数: 0

Giant quantum oscillations of acoustoelectric current in narrow graphene nanoribbons 窄石墨烯纳米带中声电电流的巨大量子振荡

Journal of Physics D Pub Date : 2023-11-03 DOI: 10.1088/1361-6463/ad098c

Vl A Margulis, E E Muryumin

{"title":"Giant quantum oscillations of acoustoelectric current in narrow graphene nanoribbons","authors":"Vl A Margulis, E E Muryumin","doi":"10.1088/1361-6463/ad098c","DOIUrl":"https://doi.org/10.1088/1361-6463/ad098c","url":null,"abstract":"Abstract A theory is presented for the acoustoelectric (AE) eﬀect in narrow graphene nanoribbons (GNRs) deposited on a piezoelectric substrate when a surface acoustic wave (SAW) is launched onto the surface of the piezoelectric. It is assumed that the electron density in such GNRs can be controlled by applying an external gate voltage, and the acoustic wavelength is much smaller than the mean free path of electrons, so that the quantum mode of interaction of those electrons with the SAW in realized. Using the kinetic theoryapproach, we calculate the AE current ﬂowing through the GNR sample and arising as a result of momentum transfer from coherent SAW phonons to conduction electrons. It is shown that size quantization of the electron energy spectrum in narrow GNRs leads to giant periodic oscillations of the AE current with a change in the gate voltage. AE current surges occur whenever the Fermi level, rising with increasing gate voltage, crosses in turn the bottom of each of the successive size-quantized electron energy subbands. The oscillations predicted are giant in the sense that the maximum values of the current exceed its minimum values by at least an order of magnitude, and they can be observed in narrow GNRs ∼ 10 nm wide even at room temperature.&#xD;","PeriodicalId":16833,"journal":{"name":"Journal of Physics D","volume":"102 4‐5","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135818972","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}

引用次数: 0