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SSRN 2024年

作者： Emu, Injamamul Hoque Samuels, Brian C. Karmakar, Subrata Hamid, Md. Abdul Shiam, Istiaq Firoz Sarkar, Pallab Kumar Tasnim, Ayesha Haque, Ariful Droopad, Ravi Ingram School of Engineering Texas State University San MarcosTX78666 United States Materials Science Engineering & Commercialization Program Texas State University San MarcosTX78666 United States

High-quality crystalline copper gallate (CuGa2O4) thin films were grown on c-plane sapphire substrates using the pulsed laser deposition (PLD) technique by optimizing the growth parameters (i.e., temperature, oxygen chamber pressure, and laser energy density). The obtained XRD patterns validated that the preferred orientation of the crystalline CuGa2O4 thin film is along the [111] direction, and the crystallinity of the films improved with increasing substrate temperature while maintaining a constant O2 pressure, as assessed by measuring the full width at half maximum (FWHM) of the prominent (222) plane. Reducing the oxygen pressure leads to the emergence of β-Ga2O3 peaks rather than the CuGa2O4 peaks due to the incomplete oxidation of copper (Cu). Subsequent XRD phi (φ) scans revealed a sixfold rotational symmetry of CuGa2O4 and a 30º epitaxial relationship between the film and the sapphire substrate. X-ray photoelectron spectroscopy (XPS) spectra confirmed the presence of Cu1+, Cu2+, and Ga3+ oxidation states in the films. Increasing laser energy density resulted in the complete oxidation of Cu and an increase in the film thickness from 51.8 nm to 183.4 nm. The direct bandgap of CuGa2O4 films was determined to be approximately 4.51±0.01 eV by analyzing the UV-Vis absorbance spectra using the Tauc equation. The refractive index was found to be approximately 2.05±0.01 based on the spectroscopic ellipsometry data. While the impact of increasing laser energy density was negligible on the parameters such as crystal structure, rotational symmetry, oxidation states of gallium (Ga), oxygen (O), bandgap, and refractive index of CuGa2O4 thin film, notable alterations in the oxidation state of Cu and film thickness were observed. © 2024, The Authors. All rights reserved.

关键词： Thin films

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Complex RNA-DNA hybrid nanoshapes from iterative mix-andmatch screening

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Nano Research 2021年第1期14卷 46-51页

作者： Shi Chen Zhiyuan Zhang Eugene Alforque Thomas Hermann Department of Chemistry and Biochemistry University of CaliforniaSan DiegoCA 92093USA Center for Drug Discovery Innovation University of CaliforniaSan DiegoCA 92093USA Materials Science and Engineering Program University of CaliforniaSan DiegoCA 92093USA

Hybrid nucleic acid nanostructures partition architectural and functional roles between ribonucleic acid(RNA)joints and deoxyribonucleic acid(DNA)*** self-assemble from nucleic acid modules through synergistic stabilization of marginally stable base pairing interactions within circularly closed ***,we report the development of hybrid nanoshapes that include multiple different RNA modules such as internal loop and three-way junction(3WJ)*** iterative mix-and-match screening approach was used to identify suitable DNA connectors that furnished stable nanoshapes for combinations of different RNA *** resulting complex multicomponent RNA-DNA hybrid nanoshapes were characterized by atomic force microscopy(AFM)*** research provides proof of concept for modular design,assembly and screening of RNA-DNA hybrid nanoshapes as building blocks for complex extended nucleic acid materials with features at the sub-10 nm scale.

关键词： nucleic acid nanotechnology nanoshapes ribonucleic acid(RNA)three-way junction(3WJ) RNA deoxyribonucleic acid(DNA) sub-10 nm features

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Local step-flow dynamics in thin film growth with desorption

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Physical Review materials 2024年第3期8卷 033403-033403页

作者： Xiaozhi Zhang Jeffrey G. Ulbrandt Peco Myint Andrei Fluerasu Lutz Wiegart Yugang Zhang Christie Nelson Karl F. Ludwig Randall L. Headrick Department of Physics and Materials Science Program University of Vermont Burlington Vermont 05405 USA Division of Materials Science and Engineering Boston University Boston Massachusetts 02215 USA X-ray Science Division Argonne National Laboratory Lemont Illinois 60439 USA National Synchrotron Light Source II Brookhaven National Lab Upton New York 11973 USA Department of Physics Boston University Boston Massachusetts 02215 USA

Desorption of deposited species plays a role in determining the evolution of surface morphology during crystal growth when the desorption time constant is short compared with the time to diffuse to a defect site, step edge, or kink. However, experiments to directly test the predictions of these effects are lacking. Novel techniques such as in situ coherent x-ray scattering can provide significant new information. Herein we present x-ray photon correlation spectroscopy (XPCS) measurements during diindenoperylene (DIP) vapor deposition on thermally oxidized silicon surfaces. DIP forms a nearly complete two-dimensional first layer over the range of temperatures studied (40–120∘C), followed by mounded growth during subsequent deposition. Local step flow within mounds was observed, and we find that there was a terrace-length-dependent behavior of the step edge dynamics. This led to unstable growth with rapid roughening (β>0.5) and deviation from a symmetric error-function-like height profile. At high temperatures, the grooves between the mounds tend to close up leading to nearly flat polycrystalline films. Numerical analysis based on a (1+1)-dimensional model suggests that terrace-length dependent desorption of deposited ad-molecules is an essential cause of the step dynamics, and it influences the morphology evolution.

关键词： Growth Surface diffusion Surface instabilities Atomic force microscopy Surface scattering X-ray techniques

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Problems With Solutions: engineering Alkylammonium Additive Reactivity for Durable High-Quality Perovskite Films

Problems With Solutions: Engineering Alkylammonium Additive ...

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IEEE Conference Photovoltaic Specialists (PVSC)

作者： Jack R. Palmer Soichiro Iwamoto Clark Han Connor J. Dolan Hendrik M. Vossler Sean P. Dunfield David P. Fenning Materials Science and Engineering Program UC San Diego La Jolla CA United States Department of NanoEngineering UC San Diego La Jolla CA United States

ISBN: (数字)9781665464260

ISBN: (纸本)9781665475822

Methylammonium chloride (MACl) is used as a volatile additive in most high-efficiency formamidinium lead iodide (FAPbI3) perovskite solar cells (PSCs). However, MA is known to irreversibly react with FA to form n-methyl formamidinium (nMFA), which is detrimental to the absorber quality. In this work, we explore a series of alternative primary alkylammonium chlorides (RACls) in an antisolvent-free deposition. We analyze ink reactivity toward FA, film crystallinity, photoluminescence quantum yield (PLQY), and durability under light and heat. We find that the alkyl chain has a significant effect on reaction rate with FA, with isopropylammonium (iPA) showing a 10 times slower reaction rate than MA. Diffraction intensity of the (001) perovskite peak is maximized with ethylammonium (EA) and iPA, then decreases with the increasing alkyl chain length of n-propyl (nPA) and n-butyl (nBA) ammonium. Importantly, films cast from aged solutions containing the alternative RACl additives all formed majority black perovskite α-phase, while the MACl controls did not, highlighting the negative impact of nMFA. PLQY of alternative additives were comparable to pristine MACl and was retained in films made after solution aging. Durability tests of unencapsulated films in inert atmosphere under 0.6-sun illumination and 85°C heating revealed increased stability of the black perovskite α-phase by replacing MA, with iPA and nBA offering the best phase stability. Unoptimized devices prepared with fresh inks containing iPACl deliver performance on par with the MACl control. The results presented herein demonstrate promising alternative volatile additives to replace MACl in FAPbI3-based perovskite solar cells.

关键词： Heating systems Photovoltaic systems Performance evaluation Additives Photovoltaic cells Ink Photoluminescence Aging Perovskites Stability analysis

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Inclusive STEAM education in diverse disciplines of sustainable energy and AI

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Energy and AI 2022年第1期7卷 43-47页

作者： Michelle Skowronek Renée M.Gilberti Michael Petro Christopher Sancomb Stacy Maddern Jasna Jankovic Urban and Community Studies University of ConnecticutStorrsUnited States McNair Scholars Program Center for Academic ProgramsInstitute for Student SuccessUniversity of ConnecticutStorrsUnited States Louis Stokes Alliance for Minority Participation Institute for Student SuccessUniversity of ConnecticutStorrsUnited States Industrial Design Department of Art and Art HistorySchool of Fine ArtsUniversity of ConnecticutStorrsUnited States Materials Science and Engineering Department Center for Clean Energy Engineering and Institute for Materials ScienceUniversity of ConnecticutStorrsUnited States

This perspective article explores challenges of traditional education in science,technology,engineering and math(STEM)as it relates to emerging sustainable energy and artificial intelligence development.A special perspective is given for education of underrepresented and minority students in *** discuss the existing issues and suggest that,for an equitable sustainable education in the area of energy,artificial intelligence and sustainable society in general,science and technology knowledge should be acquired in conjunction with humanities and arts,through a multidisciplinary STEM+Art(STEAM)approach and special programming that supports inclusion of diverse professional,socio-economical,racial and gender *** underscore that infusing technical training with social sciences,arts,ethics,and business prepares future leaders to creatively participate in solving identifiable barriers towards a sustainable *** these are challenges caused by climate change,social tensions,or systematic inequalities,such holistic and sustainable education has the power to ease complex global crises,empower and dignify all people,as well as interrupt environmental degradation.

关键词： STEM STEAM Sustainability Energy AI

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Automatic 2D Material Detection in Optical Images using Deep Learning Based Computer Vision 4

Automatic 2D Material Detection in Optical Images using Deep...

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AI and Optical Data sciences IV 2023

作者： Ramezani, Fereshteh Parvez, Sheikh Fix, J. Pierce Battaglin, Arthur Whyte, Seamus Borys, Nicholas J. Whitaker, Bradley Electrical and Computer Engineering Department Montana State University Bozeman United States Department of Physics Montana State University Bozeman United States Materials Science Program Montana State University Bozeman United States Optical Technology Center Montana State University Bozeman United States

ISBN: (纸本)9781510659810

Computer vision algorithms can quickly analyze numerous images and identify useful information with high accuracy. Recently, computer vision has been used to identify 2D materials in microscope images. 2D materials have important fundamental properties allowing for their use in many potential applications, including many in quantum information science and engineering. In order to use these materials for research and product development, single-layer 2D crystallites must be prepared through an exfoliation procedure and then identified using reflected light optical microscopy. Performing these searches manually is a time-consuming and tedious task. Deploying deep learning-based computer vision algorithms for 2D material search can automate the flake detection task with minimal need for human intervention. In this work, we have implemented a new deep learning pipeline to classify crystallites of 2D materials based on coarse thickness classifications in reflected-light optical micrographs. We have used DetectorRS as the object detector and trained it on 177 images containing hexagonal boron nitride (hBN) flakes of varying thickness. The trained model achieved a high detection accuracy for the rare category of thin flakes ( © 2023 SPIE.

关键词： Object detection

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Computational inverse design of acoustoplasmonic metasurfaces

arXiv

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arXiv 2025年

作者： Holland, Julia E. Boechler, Nicholas Poulikakos, Lisa V. Department of Mechanical & Aerospace Engineering UC La Jolla San DiegoCA92093-0021 United States Program in Materials Science & Engineering UC La Jolla San DiegoCA92093-0021 United States

Optical and acoustic metasurfaces are two-dimensional arrays of subwavelength elements that locally modulate or phase shift incident waves. Acoustoplasmonic metasurfaces combine the physics of light and sound, producing acoustic wavefronts in response to optical stimuli. Herein, we present a computational inverse acoustoplasmonic metasurface design algorithm for desired optically-generated acoustic wave fields. We consider gold nanoparticles producing spherical acoustic waves in water, and the resulting acoustic wave propagation along the plane containing the nanoparticle array. We demonstrate how our algorithm can be used to design metasurfaces that can be used to achieve complex acoustic wave fields. This includes the design of a single metasurface that produces acoustic wave fields mimicking two different Morse code patterns upon stimulation with two orthogonal polarization states of light. This work provides a new tool for the design of complex optically generated acoustic wavefronts, enabling functionality beyond what would be achievable with off-optical-resonance optoacoustic excitation. Copyright © 2025, The Authors. All rights reserved.

关键词： Acoustic wave propagation

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Textured BaTiO3 nanorod arrays synthesized via hydrothermal method: Enhanced degradation of Rhodamine B with piezocatalysis

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Ceramics International 2025年

作者： Chiu, Yen-Lun Chang, Kao-Shuo Program on Key Materials Academy of Innovative Semiconductor and Sustainable Manufacturing National Cheng Kung University No.1 University Road Tainan City70101 Taiwan Department of Materials Science & Engineering National Cheng Kung University No.1 University Road Tainan City70101 Taiwan

This paper presents a hydrothermal method for fabricating textured BaTiO3 (BTO) nanorod arrays with high crystallinity on fluorine-doped tin oxide (FTO) substrates by applying a polarization treatment to the samples to explore the feasibility of enhancing their piezoelectric properties. The preparation of highly textured BTO nanorod arrays using a two-step hydrothermal process was investigated in detail, including the spin-coating process for depositing the TiO2 seed layer, the influence of solution acidity on the hydrothermal synthesis of TiO2 nanorod arrays, and the formation mechanism of textured BTO nanostructures. The piezoelectric constants (d33) of the samples were determined using piezoresponse force microscopy. S-BTO(P), which has high crystallinity and preferential orientation, achieves a d33 as high as 85.4 p.m./V after poling, which is 3.2 times higher than that without textured structures and poling. Our findings revealed that chemically controlling and inducing a preferential orientation in the crystal structure of piezoelectric materials with a seed layer and specific hydrothermal conditions can significantly enhance their piezoelectric properties after poling, making them excellent candidates for piezoelectric devices. Especially, this study confirms that the piezoelectric-enhanced charge separation in poled BTO nanorod arrays enables efficient generation of reactive species under ultrasonication, leading to effective degradation of RhB. The strong piezocatalytic performance highlights the material's potential for practical applications in environmental pollutant removal. © 2025 Elsevier Ltd and Techna Group S.r.l.

关键词： Piezoelectricity

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Identifying Prognostic Markers of Non-small Cell Lung Carcinoma Using Bioinformatics

Identifying Prognostic Markers of Non-small Cell Lung Carcin...

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International Conference on Industrial Instrumentation and Control,ICI2C 2021

作者： Khan, Siladitya Chakraborty, Debamitra Department of Biomedical Engineering University of Rochester RochesterNY14627 United States Goergen Institute for Data Science University of Rochester RochesterNY14627 United States Materials Science Graduate Program University of Rochester RochesterNY14627 United States

ISBN: (纸本)9789811670107

We present a transcriptomics pipeline for performing the functional analysis of array expression profiling data of normal and adenocarcinoma lung tissue. Our aims are twofold, firstly to elucidate molecular processes that transform normal tissue, to a lung adenocarcinoma. Following this, we perform functional analysis to screen potential hub genes and demonstrate their value in cancer prognosis. Analysis was performed on a total of 500 differentially expressed genes (DEG), screened for their regulation and transcriptional modulation in a female population carrying non–small cell lung carcinoma (NSCLC). Key pathways like cytokine-cytokine receptors, ECM receptor interactions, and TNF signaling were identified suggesting a potential role in lung tumorigenesis. © 2022, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.

关键词： Bioinformatics

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Nucleation effects of coccoliths in portland cement

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Matter 2025年

作者： Beatty, Danielle N. Srubar, Wil V. Materials Science and Engineering Program University of Colorado Boulder 4001 Discovery Drive UCB 027 BoulderCO80303 United States Department of Civil Environmental and Architectural Engineering University of Colorado Boulder 1111 Engineering Drive ECOT 441 UCB 428 BoulderCO80309 United States

This work explores the use of photosynthesized coccoliths (intricate CaCO3 particles) as a nucleation agent or cement replacement in portland cement paste. First, coccoliths were produced and harvested from the marine microalgae Emiliania huxleyi and the particle size, morphology, and mineralogy were characterized. Then, the nucleation effects of E. huxleyi coccoliths as seeding agent (0.5, 1, 3, or 5 wt % additions) and limestone filler (5 and 15 wt % cement replacements) were studied using isothermal conduction calorimetry and compressive strength testing. The results were compared with five commercially available CaCO3 sources used as nucleation agents and fillers. While the high surface area of coccoliths (12.22 m2/g) enhanced water demand, it also enhanced nucleation during cement hydration without accelerating hydration, leading to enhanced early-age strength without detriments to 28-day strength. Results highlight a potential carbon reduction strategy, namely employing photosynthesis as a method of mineral admixture production, for the cement and concrete industry. © 2025 Elsevier Inc.

关键词： Portland cement

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