{"title":"p-(001)NiO/n-(0001)ZnO Heterostructures based Ultraviolet Photodetectors","authors":"Amandeep Kaur, Bhabani Prasad Sahoo, Ajoy Biswas, Subhabrata Dhar","doi":"arxiv-2409.11922","DOIUrl":"https://doi.org/arxiv-2409.11922","url":null,"abstract":"We investigate the potential of epitaxial (001)p-NiO/(0001)n-ZnO\u0000heterostructures grown on (0001)sapphire substrates by pulsed laser deposition\u0000technique for ultraviolet photodetector application. Our study reveals that in\u0000the self-powered mode, these devices can serve as effective photodetectors for\u0000the UV-A band (320-400 nm) with response time as short as 400 microseconds.\u0000Peak responsivity as high as 5mA/W at zero bias condition have been achieved.\u0000These devices also show a very high level of stability under repeated on/off\u0000illumination cycles over a long period of time. Furthermore, we find that the\u0000response time of these detectors can be controlled from several microseconds to\u0000thousands of seconds by applying bias both in the forward and the reverse\u0000directions. This persistent photoconductivity effect has been explained in\u0000terms of the field induced change in the capture barrier height associated with\u0000certain traps located at the junction.","PeriodicalId":501083,"journal":{"name":"arXiv - PHYS - Applied Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142259900","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}
{"title":"Normal/inverse Doppler effect of backward volume magnetostatic spin waves","authors":"Xuhui Su, Dawei Wang, Shaojie Hu","doi":"arxiv-2409.11674","DOIUrl":"https://doi.org/arxiv-2409.11674","url":null,"abstract":"Spin waves (SWs) and their quanta, magnons, play a crucial role in enabling\u0000low-power information transfer in future spintronic devices. In backward volume\u0000magnetostatic spin waves (BVMSWs), the dispersion relation shows a negative\u0000group velocity at low wave numbers due to dipole-dipole interactions and a\u0000positive group velocity at high wave numbers, driven by exchange interactions.\u0000This duality complicates the analysis of intrinsic interactions by obscuring\u0000the clear identification of wave vectors. Here, we offer an innovative approach\u0000to distinguish between spin waves with varying wave vectors more effectively by\u0000the normal/inverse spin wave Doppler effect. The spin waves at low wave numbers\u0000display an inverse Doppler effect because their phase and group velocities are\u0000anti-parallel. Conversely, at high wave numbers, a normal Doppler effect occurs\u0000due to the parallel alignment of phase and group velocities. Analyzing the spin\u0000wave Doppler effect is essential for understanding intrinsic interactions and\u0000can also help mitigate serious interference issues in the design of spin logic\u0000circuits.","PeriodicalId":501083,"journal":{"name":"arXiv - PHYS - Applied Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142259901","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}
Nima Taghipour, Mariona Dalmases, Guy Luke Whitworth, Yongjie Wang, Gerasimos Konstantatos
{"title":"Ultrafast cascade charge transfer in multi bandgap colloidal quantum dot solids enables threshold reduction for optical gain and stimulated emission","authors":"Nima Taghipour, Mariona Dalmases, Guy Luke Whitworth, Yongjie Wang, Gerasimos Konstantatos","doi":"arxiv-2409.11982","DOIUrl":"https://doi.org/arxiv-2409.11982","url":null,"abstract":"Achieving low-threshold infrared stimulated emission in solution-processed\u0000quantum dots is critical to enable real-life application including photonic\u0000integrated circuits (PICs), LIDAR application and optical telecommunication.\u0000However, realization of low threshold infrared gain is fundamentally\u0000challenging due to high degeneracy of the first emissive state (e.g., 8-fold)\u0000and fast Auger recombination. In this letter, we demonstrate ultralow-threshold\u0000infrared stimulated emission with an onset of 110 uJ.cm-2 employing cascade\u0000charge transfer (CT) in Pb-chalcogenide colloidal quantum dot (CQD) solids. In\u0000doing so, we investigate this idea in two different architectures including a\u0000mixture of multiband gap CQDs and layer-by-layer (LBL) configuration. Using\u0000transient absorption spectroscopy, we show ultrafast cascade CT from large\u0000band-gap PbS CQD to small band-gap PbS/PbSSe core/shell CQDs in LBL (~ 2 ps)\u0000and mixture (~ 9 ps) configuration. These results indicate the feasibility of\u0000using cascade CT as an efficient method to reduce optical gain threshold in CQD\u0000solid films.","PeriodicalId":501083,"journal":{"name":"arXiv - PHYS - Applied Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142259898","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}
{"title":"Overcoming Ambient Drift and Negative-Bias Temperature Instability in Foundry Carbon Nanotube Transistors","authors":"Andrew Yu, Tathagata Srimani, Max Shulaker","doi":"arxiv-2409.11297","DOIUrl":"https://doi.org/arxiv-2409.11297","url":null,"abstract":"Back-end-of-line (BEOL) logic integration is emerging as a complementary\u0000scaling path to supplement front-end-of-line (FEOL) Silicon. Among various\u0000options for BEOL logic, Carbon Nanotube Field-Effect Transistors (CNFETs) have\u0000been integrated within commercial silicon foundries, and complex CNFET circuits\u0000(e.g., RISC-V core, SRAM arrays) have been demonstrated. However, there lacks\u0000comprehensive studies that analyze the ambient drift (i.e., air-stability) and\u0000reliability of CNFETs. Here, for the first time, we thoroughly characterize and\u0000demonstrate how to overcome ambient drift and negative bias temperature\u0000instability (NBTI) in CNFETs using the following techniques: (1) Silicon\u0000Nitride encapsulation to limit ambient atmosphere induced threshold voltage\u0000shift (~8x reduction of median VT shift over 90 days) and (2) AC/pulsed\u0000operation to significantly improve CNFET NBTI vs. DC operation across a wide\u0000frequency range (e.g., 20% duty cycle AC operation at 10 MHz could extend CNFET\u0000NBTI time-to-failure by >10000x vs. DC for a target VT shift tolerance < 100 mV\u0000with gate stress bias VGS,stress = -1.2 V at 125 C).","PeriodicalId":501083,"journal":{"name":"arXiv - PHYS - Applied Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142259955","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}
{"title":"Unattended field measurement of bird source level","authors":"Guillaume Dutilleux","doi":"arxiv-2409.10957","DOIUrl":"https://doi.org/arxiv-2409.10957","url":null,"abstract":"Sound power levels or so-called source levels are essential quantities when\u0000it comes to evaluating the active space of bird species, both in the study of\u0000animal communication and when designing bioacoustic monitoring schemes.\u0000However, little data is available in the literature. In this paper I\u0000demonstrate the feasibility of the measurement of apparent sound power in the\u0000field for bird species by using a calibrated 4-microphone horizontal array\u0000deployed on the ground. Time differences of arrival allow for the location of\u0000the sound source. Assuming a point source, the apparent sound power level is\u0000estimated after correcting for ground reflection and spherical divergence but\u0000cannot be corrected for source directivity. The benefits of my approach that is\u0000inspired from engineering measurement standards for elevated sound sources, is\u0000to minimize the contribution from ground reflections and to allow for\u0000unattended measurements, or measurements when the bird is not visible, owing to\u0000either foliage or obscurity. Moreover, my paper brings new data on sound power\u0000for 4 species of birds.","PeriodicalId":501083,"journal":{"name":"arXiv - PHYS - Applied Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142259902","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}
Wojciech Marciniak, Joanna Marciniak, José Ángel Castellanos-Reyes, Mirosław Werwiński
{"title":"Giant magnetocrystalline anisotropy energy in Fe--Co alloy under uniaxial compression: first-principles prediction","authors":"Wojciech Marciniak, Joanna Marciniak, José Ángel Castellanos-Reyes, Mirosław Werwiński","doi":"arxiv-2409.11388","DOIUrl":"https://doi.org/arxiv-2409.11388","url":null,"abstract":"Uniaxially strained Fe--Co disordered alloys have emerged as promising\u0000candidates for cost-effective rare-earth-free permanent magnets due to their\u0000high magnetocrystalline anisotropy energy (MAE). Using first-principles, fully\u0000relativistic calculations within the coherent potential approximation and PBE\u0000exchange-correlation potential, we explore the MAE of tetragonal Fe--Co alloys\u0000under uniaxial compression. Our results reveal a previously uncharted high-MAE\u0000region, distinct from known structures and accessible through uniaxial\u0000compression.","PeriodicalId":501083,"journal":{"name":"arXiv - PHYS - Applied Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142259957","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}
Alessandro Rossi, Ian Buchanan, Alberto Astolfo, Martyna Michalska, Daniel Briglin, Anton Charman, Daniel Josell, Sandro Olivo, Ioannis Papakonstantinou
{"title":"Fabrication of Ultra-Thick Masks for X-ray Phase Contrast Imaging at Higher Energy","authors":"Alessandro Rossi, Ian Buchanan, Alberto Astolfo, Martyna Michalska, Daniel Briglin, Anton Charman, Daniel Josell, Sandro Olivo, Ioannis Papakonstantinou","doi":"arxiv-2409.11237","DOIUrl":"https://doi.org/arxiv-2409.11237","url":null,"abstract":"X-ray phase contrast imaging (XPCI) provides higher sensitivity to contrast\u0000between low absorbing objects that can be invisible to conventional\u0000attenuation-based X-ray imaging. XPCI's main application has been so far\u0000focused on medical areas at relatively low energies (< 100 keV). The\u0000translation to higher energy for industrial applications, where energies above\u0000150 keV are often needed, is hindered by the lack of masks/gratings with\u0000sufficiently thick gold septa. Fabricating such structures with apertures of\u0000tens of micrometers becomes difficult at depths greater than a few hundreds of\u0000micrometers due to aspect ratio dependent effects such as anisotropic etching,\u0000and preferential gold (Au) deposition at the top of the apertures. In this\u0000work, these difficulties are overcome by Deep Reactive Ion Etching optimized by\u0000a stepped parameters approach and bismuth-mediated superconformal filling of\u0000Au, ultimately resulting in 500 micrometers deep silicon masks filled with Au\u0000at bulk density. The obtained masks, tested in an Edge Illumination XPCI system\u0000with a conventional source and a photon-counting detector, show good agreement\u0000with simulations at different energy thresholds. They also demonstrate a higher\u0000phase sensitivity for highly absorbing objects when compared to lower aspect\u0000ratio masks, proving their potential for industrial non-destructive testing.","PeriodicalId":501083,"journal":{"name":"arXiv - PHYS - Applied Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142259954","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}
{"title":"Dispersive wave propagation in disordered flexible fibers enhances stress attenuation","authors":"Peng Wang, Thomas Pähtz, Kun Luo, Yu Guo","doi":"arxiv-2409.10926","DOIUrl":"https://doi.org/arxiv-2409.10926","url":null,"abstract":"We experimentally and computationally analyze impact-shock-induced stress\u0000wave propagation in packings of disordered flexible fibers. We find that\u0000dispersive wave propagation, associated with large stress attenuation, occurs\u0000much more prevalently in systems with larger fiber aspect ratios and moderate\u0000fiber flexibility. We trace these features to the microstructural properties of\u0000fiber contact chains and the energy-trapping abilities of deformable fibers.\u0000These findings provide new insights into physics of the shock-impacted flexible\u0000fiber packings and open the way towards an improved granular-material-based\u0000damping technology.","PeriodicalId":501083,"journal":{"name":"arXiv - PHYS - Applied Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142259956","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}
{"title":"hklhop: a Selection Tool for Asymmetric Reflections of Spherically Bent Crystal Analysers for High Resolution X-ray Spectroscopy","authors":"Jared E. Abramson, Yeu Chen, Gerald T. Seidler","doi":"arxiv-2409.10698","DOIUrl":"https://doi.org/arxiv-2409.10698","url":null,"abstract":"High resolution, hard x-ray spectroscopy at synchrotron x-ray light sources\u0000commonly uses spherically bent crystal analyzers (SBCAs) formed by shaping a\u0000single crystal wafer to a spherical backing. These Rowland circle optics are\u0000almost always used in a 'symmetric' (or nearly symmetric) configuration wherein\u0000the reciprocal lattice vector used for energy selectivity via diffraction is\u0000coincident with the normal vector to the curved wafer surface. However,\u0000Gironda, et al., recently proposed that asymmetric operation of SBCA, wherein\u0000the reciprocal lattice vector is no longer normal to the wafer surface, has\u0000significant operational benefits and has been an underutilized opportunity.\u0000First, those authors find improved energy resolution through decreased Johann\u0000error, or equivalently find increased solid angle at a chosen experimental\u0000tolerance for energy broadening. Second, they find productive, high-resolution\u0000use of a large number of reciprocal lattice vectors from a single SBCA, thus\u0000enabling operation over a wide energy range without need to exchange SBCA upon\u0000making large changes in desired photon energy. These observations hold the\u0000potential to improve performance, increase flexibility and decrease cost for\u0000both laboratory and synchrotron applications. Given these motivations, we\u0000report an open-source software package, hklhop, that enables exploration of the\u0000complex space of analyzer wafer choice, experimental energy range or ranges,\u0000and desired suppression of Johann error. This package can guide both the design\u0000and the day-to-day operations of Rowland spectrometers enabled for asymmetric\u0000use.","PeriodicalId":501083,"journal":{"name":"arXiv - PHYS - Applied Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142259953","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}
{"title":"A semi-analytical method using auxiliary sine series for vibration and sound radiation of a rectangular plate with elastic edges","authors":"Guoming Deng, Xian Wu, Changxiao Shao, Songlin Zheng, Jianwang Shao","doi":"arxiv-2409.09929","DOIUrl":"https://doi.org/arxiv-2409.09929","url":null,"abstract":"This paper proposes an efficient semi-analytical method using auxiliary sine\u0000series for transverse vibration and sound radiation of a thin rectangular plate\u0000with edges elastically restrained against translation and rotation. The\u0000formulation, constructed by two-dimensional sine and/or cosine series, can\u0000approximately express the bending displacement, and calculate vibration and\u0000sound radiation under excitation of point force, arbitrary-angle plane wave, or\u0000diffuse acoustic field with acceptable accuracy. It is also applied for baffled\u0000or unbaffled conditions. A post-process program is developed to predict\u0000vibrating frequencies and modes, mean square velocity spectrum, and sound\u0000transmission loss via reduced-order integrals of radiation impedances. The\u0000method is validated by experiment and simulation results, demonstrating\u0000accurate and efficient computation using a single program for transverse\u0000vibration and sound radiation of a plate under different elastic boundary\u0000conditions and different excitations. Formulas given in this paper provide a\u0000basis for the code development on transverse vibration and sound radiation\u0000analysis of thin plates.","PeriodicalId":501083,"journal":{"name":"arXiv - PHYS - Applied Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142259958","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}