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Mukhamale SV, Kartha MJ, Khirade PP. Experimental, theoretical and numerical simulation-based investigations on the fabricated Cu 2ZnSn thin-film-based Schottky diodes with enhanced electron transport for solar cell. Sci Rep 2024; 14:15970. [PMID: 38987551 PMCID: PMC11236998 DOI: 10.1038/s41598-024-63857-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2023] [Accepted: 06/03/2024] [Indexed: 07/12/2024] Open
Abstract
Copper-zinc-tin Cu2ZnSn (CZT) thin films are promising materials for solar cell applications. This thin film was deposited on a fluorine-doped tin oxide (FTO) using an electrochemical deposition hierarchy. X-ray diffraction of thin-film studies confirms the variation in the structural orientation of CZT on the FTO surface. As the pH of the solution is increased, the nature of the CZT thin-film aggregate changes from a fern-like leaf CZT dendrite crystal to a disk pattern. The FE-SEM surface micrograph shows the dendrite fern leaf and sharp edge disks. The 2-D diffusion limitation aggregation under slippery conditions for ternary thin films was performed for the first time. The simulation showed that by changing the diffusing species, the sticking probability was responsible for the pH-dependent morphological change. Convincingly, diffusion-limited aggregation (DLA) simulations confirm that the initial structure of copper is responsible for the final structure of the CZT thin films. An experimental simulation with pH as a controlled parameter revealed phase transition in CZT thin films. The top and back contact of Ag-CZT thin films based on Schottky behavior give a better electronic mechanism in superstrate and substrate solar cells.
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Affiliation(s)
- Sachin V Mukhamale
- Department of Physics, Shri Pundlik Maharaj Mahavidyalaya, MS, Nandura Rly, 443404, India.
- Department of Physics, Savitribai Phule Pune University, Pune, MS, 411007, India.
| | - Moses J Kartha
- Department of Physics, Savitribai Phule Pune University, Pune, MS, 411007, India
- Department of Physics, KLE Society's Science and Commerce College, Kalamboli, Navi Mumbai, MS, 410218, India
| | - Pankaj P Khirade
- Department of Physics, Shri Shivaji Science College, Amravati, MS, 444603, India
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2
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Zuarez-Chamba M, Tuba-Guamán D, Quishpe M, Vizuete K, Debut A, Herrera-Robledo M. Photocatalytic degradation of bisphenol A on BiOI nanostructured films under visible LED light irradiation. J Photochem Photobiol A Chem 2022. [DOI: 10.1016/j.jphotochem.2022.114021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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3
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Mukhopadhyay S, Bera SC, Ramola K. Observation of two-step aggregation kinetics of Amyloid- βproteins from fractal analysis. Phys Biol 2022; 19. [PMID: 35381581 DOI: 10.1088/1478-3975/ac6478] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Accepted: 04/05/2022] [Indexed: 11/12/2022]
Abstract
Self-aggregation in proteins has long been studied and modeled due to its ubiquity and importance in many biological contexts. Several models propose a two step aggregation mechanism, consisting of linear growth of fibrils and secondary growth involving branch formation. Single molecule imaging techniques such as total internal reflection fluorescence (TIRF) microscopy can provide direct evidence of such mechanisms, however, analyzing such large data-sets is challenging. In this paper, we analyze for the first time, images of growing amyloid fibrils obtained from TIRF microscopy using the techniques of fractal geometry, which provides a natural framework to disentangle the two types of growth mechanisms at play. We find that after an initial linear growth phase, identified by a plateau in the average fractal dimension with time, the occurrence of branching events leads to a further increase in the fractal dimension, with a final saturation value ≈ 2. This provides direct evidence of the two-step nature of the aggregation kinetics of Amyloid-βproteins, with an initial linear elongation phase followed by branching at later times.
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Affiliation(s)
- Soham Mukhopadhyay
- Tata Institute of Fundamental Research Centre for Interdisciplinary Sciences, 36/P, Gopanpally Tanda, Serilingampally Mandal, Hyderabad, Telangana, 500046, INDIA
| | - Subhas C Bera
- Friedrich-Alexander-Universität Erlangen-Nürnberg, Cauerstr. 3, Erlangen, Bayern, 91058, GERMANY
| | - Kabir Ramola
- Tata Institute of Fundamental Research Centre for Interdisciplinary Sciences, 36/P, Gopanpally Tanda, Serilingampally Mandal, Hyderabad, Telangana, 500046, INDIA
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4
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Ţălu Ş, Guzzo PL, Salerno M, Bramowicz M, Kulesza S. Morphologic characterization and fractal analysis of lapped and polished surfaces of quartz single crystals. Microsc Res Tech 2022; 85:721-727. [PMID: 34558750 DOI: 10.1002/jemt.23943] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Revised: 09/08/2021] [Accepted: 09/12/2021] [Indexed: 02/05/2023]
Abstract
Lapping and polishing are industrial processes sometimes used alternatively for surface finishing of hard and brittle materials. This article presents advanced image analysis of surfaces of quartz crystal blanks finished by lapping and polishing. Scanning electron micrographs were obtained from workpiece surfaces parallel to Y-, AT-, and Z-cut crystal planes treated with different normal stress and abrasive grit size, and stereometric and fractal/multifractal approaches were used to analyze the respective surfaces. Fractal dimensions and segmentation parameters were able to decode the effect of normal stress increasing on the surface roughness of lapped and polished samples. Moreover, the texture isotropy and the bifractal-hence agglomerated-nature of the surface patterns, suggest that both treatments dismiss the anisotropic signature of hardness and fracture toughness inherent to each crystal plane. This study provides promising results regarding the applicability of fractal analysis in the assessment of surfaces severely worn by the combined effect of brittle microcracking and plastic deformation mechanisms.
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Affiliation(s)
- Ştefan Ţălu
- Technical University of Cluj-Napoca, The Directorate of Research, Development and Innovation Management (DMCDI), Cluj county, Romania
| | - Pedro L Guzzo
- Department of Mining Engineering, Federal University of Pernambuco, Recife, Pernambuco, Brazil
| | - Marco Salerno
- Institute for Globally Distributed Open Research and Education (IGDORE) and Ronin Institute, Montclair, New Jersey, USA
| | - Miroslaw Bramowicz
- Faculty of Technical Sciences, University of Warmia and Mazury in Olsztyn, Olsztyn, Poland
| | - Slawomir Kulesza
- Faculty of Technical Sciences, University of Warmia and Mazury in Olsztyn, Olsztyn, Poland
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Tomchuk OV, Avdeev MV, Bulavin LA. Modeling fractal aggregates of polydisperse particles with tunable dimension. Colloids Surf A Physicochem Eng Asp 2020. [DOI: 10.1016/j.colsurfa.2020.125331] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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6
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Matos RS, Ramos GQ, da Fonseca Filho HD, Ţălu Ş. Advanced micromorphology study of microbial films grown on Kefir loaded with Açaí extract. Micron 2020; 137:102912. [PMID: 32585567 DOI: 10.1016/j.micron.2020.102912] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2020] [Revised: 06/15/2020] [Accepted: 06/15/2020] [Indexed: 02/07/2023]
Abstract
In this work, an advanced analysis of the 3D surface microtexture of the microbial films grown on Kefir loaded with Açaí extract was performed. Atomic force microscopy was used to characterize the 3D surface microtexture data in correlation with the stereometric analyses to allow a better understanding of the surface micromorphology consistent with ISO 25178-2: 2012. Two new parameters, fractal succolarity and fractal lacunarity, have been inserted for a quantitative approach to microtexture. The results revealed that the morphology was affected by the increase of the Açaí concentration in biofilms, as well as the fractal succolarity and lacunarity. Adhesive bacteria of the genus Lactobacillus were observed for the lowest concentrations of Açaí. Moreover, it was found that the surface of the biofilms has shown saturation when the concentration has changed from 4 to 6 % of Açaí. These results are of great interest in the characterization of surfaces with promising application like skin dressing.
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Affiliation(s)
- Robert S Matos
- Federal University of Amapá, Amazonian Materials Group, Physics Department, Amapá, Brazil; Federal University of Sergipe, Materials Engineering Department, Sergipe, Brazil
| | - Glenda Q Ramos
- Postgraduate Program in Tropical Medicine, State University of Amazonas, Manaus, Amazonas, Brazil
| | - Henrique D da Fonseca Filho
- Federal University of Amazonas, Laboratory of Nanomaterials Synthesis and Nanoscopy, Physics Department, Amazonas, Brazil.
| | - Ştefan Ţălu
- Technical University of Cluj-Napoca, The Directorate of Research, Development and Innovation Management (DMCDI), Cluj County, Romania
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Moruzzi RB, Oliveira ALD, Almeida TD. FRACTAL AGGREGATES EVOLUTION DURING FLOCCULATION. BRAZILIAN JOURNAL OF CHEMICAL ENGINEERING 2018. [DOI: 10.1590/0104-6632.20180354s20170231] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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A highly conductive thin film composite based on silver nanoparticles and malic acid for selective electrochemical sensing of trichloroacetic acid. Anal Chim Acta 2018; 1036:33-48. [PMID: 30253835 DOI: 10.1016/j.aca.2018.06.084] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2018] [Revised: 06/25/2018] [Accepted: 06/30/2018] [Indexed: 01/01/2023]
Abstract
A highly conductive thin film composite based on silver nanoparticles (AgNPs) and malic acid (MA) was deposited on glassy carbon electrode (GCE) for the selective and sensitive electrochemical sensing of trichloroacetic acid (TCA). The casting solution containing MA functionalized AgNPs was employed as a precursor for the thermal deposition of the AgNPs integrated MA thin film composite onto the GCE surface. The uniform coverage of AgNPs within the thin film composite at GCE was obtained by field emission scanning electron microscopy (FESEM). A significantly high charge transfer resistance of the modified electrode (85.7 Ω for AgNPs-MA/GCE in 2 mM [Fe(CN)6]3-/4- at a bias of +0.235 V as compared to bare GCE (38.01 Ω) verified the optimum coating of AgNPs-MA composite at the surface of the electrode. The AgNPs-MA composite deposited GCE revealed substantial electrocatalytic activity toward TCA reduction with significantly enhanced reduction current. The novel electrode manifested a linear square wave voltammetric (SWV) response over the concentration ranges of 0.1-2 (R2 = 0.9953) and 4-100 μM (R2 = 0.9969) with a limit of detection (LOD) and limit of quantification (LOQ) of 30 nM and 92.5 nM, respectively. The modified electrode exhibited an excellent long-term stability (30 days) with the retention of >95% of initial current. The selectivity of the proposed electrode for the determination of TCA was examined in the presence of dichloroacetic acid (DCA) and monochloroacetic acid (MCA) with the retention of high recovery percentages.
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Gigault J, Grassl B. Improving the understanding of fullerene (nC 60) aggregate structures: Fractal dimension characterization by static light scattering coupled to asymmetrical flow field flow fractionation. J Colloid Interface Sci 2017; 502:193-200. [PMID: 28486140 DOI: 10.1016/j.jcis.2017.05.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2017] [Revised: 04/28/2017] [Accepted: 05/01/2017] [Indexed: 12/01/2022]
Abstract
Fullerene (C60) aggregation mechanisms in aqueous media require considerable attention in the near future due to the heavy use and application of fullerene-based products within the context of nanotechnology. Such intensive development will result in the release of massive amounts of C60 in aqueous environmental systems in the aggregate form (nC60). In that sense, the aggregation mechanisms need to be fully determined to better evaluate the environmental fate and behavior of C60. To fulfil these needs, the aim of this work was to extensively characterize the aggregation mechanisms of fullerene aggregates in aqueous media by asymmetrical flow field fractionation (AF4) coupled to static light scattering (SLS). We developed a sequential ultrafiltration method that allows the fractionation of the whole nC60 size distribution into different size classes (1-100-200-450-800nm). Following a preliminary analysis by dynamic light scattering (DLS), we optimized several AF4 separation methods to allow screening of these colloidal size classes of nC60 with high efficiency and resolution. The fractal dimension (Df) of this entire size class was characterized directly on-line according to the radius of gyration through a combination of angle-dependent light scattering and fractal dimension analysis. We demonstrate the possible formation and persistence of colloidal populations of nC60 in aqueous media from a few nanometers up to 800nm. Df values ranging from 1.2 to 2.8, based on the nC60 colloidal size range, strongly depend on the method of the sample filtration.
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Affiliation(s)
- Julien Gigault
- Laboratoire Géosciences Rennes, UMR6118, CNRS/Université de Rennes 1, 263 avenue Général Leclerc, 35000 Rennes, France.
| | - Bruno Grassl
- IPREM, UMR 5254 UPPA/CNRS Hélioparc, 2 Avenue du Président Angot, 64053 Pau cedex 09, France.
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Abdellatif MH, Salerno M, Abdelrasoul GN, Liakos I, Scarpellini A, Marras S, Diaspro A. Effect of Anderson localization on light emission from gold nanoparticle aggregates. BEILSTEIN JOURNAL OF NANOTECHNOLOGY 2016; 7:2013-2022. [PMID: 28144549 PMCID: PMC5238672 DOI: 10.3762/bjnano.7.192] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/15/2016] [Accepted: 12/07/2016] [Indexed: 06/06/2023]
Abstract
The localization of light known as Anderson localization is a common phenomenon characterizing aggregates of metallic nanostructures. The electromagnetic energy of visible light can be localized inside nanostructures below the diffraction limit by converting the optical modes into nonradiative surface plasmon resonances. The energy of the confined photons is correlated to the size and shape of the nanostructured system. In this work, we studied the photoluminescence dependence of aggregates of 14 nm diameter gold nanoparticles (AuNPs) synthesized by drop-casting a liquid suspension on two different substrates of glass and quartz. The AuNP aggregates were characterized by electron microscopy, X-ray diffraction and X-ray photoelectron spectroscopy. The dielectric constant of the surrounding medium plays a crucial role in determining the aggregate geometry, which affects the Anderson localization of light in the aggregates and hence causes a red-shift in the plasmonic resonance and in the photoluminescence emission. The geometry of the gold nanoparticle aggregates determine the strength of the Anderson localization, and hence, the light emission from the aggregates. The photoluminescence lifetime was found to be dependent on the AuNP aggregate geometry and the dielectric constant of the medium.
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Affiliation(s)
- Mohamed H Abdellatif
- Nanophysics Department, Istituto Italiano di Tecnologia, via Morego, 30, I-16163 Genova, Italy
| | - Marco Salerno
- Nanophysics Department, Istituto Italiano di Tecnologia, via Morego, 30, I-16163 Genova, Italy
| | - Gaser N Abdelrasoul
- Nanophysics Department, Istituto Italiano di Tecnologia, via Morego, 30, I-16163 Genova, Italy
| | - Ioannis Liakos
- Smart Materials Group, Istituto Italiano di Tecnologia, via Morego, 30, I-16163 Genova, Italy
| | - Alice Scarpellini
- Nanochemistry Department, Istituto Italiano di Tecnologia, via Morego, 30, I-16163 Genova, Italy
| | - Sergio Marras
- Nanochemistry Department, Istituto Italiano di Tecnologia, via Morego, 30, I-16163 Genova, Italy
| | - Alberto Diaspro
- Nanophysics Department, Istituto Italiano di Tecnologia, via Morego, 30, I-16163 Genova, Italy
- Department of Physics, University of Genoa, via Dodecaneso, 33, I-16146 Genova, Italy
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Bacaita ES, Agop M. A multiscale mechanism of drug release from polymeric matrices: confirmation through a nonlinear theoretical model. Phys Chem Chem Phys 2016; 18:21809-16. [PMID: 27436760 DOI: 10.1039/c6cp02259f] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
In this paper, we propose a new approach for the dynamics of drug delivery systems, assimilated to complex systems, an approach based on concepts like fractality, non-differentiability, and multiscale evolution. The main advantage of using these concepts is the possibility of eliminating the approximations used in the standard approach by replacing complexity with fractality, that imposes, in mathematical terms, the mandatory use of the non-differential character of defined physical quantities. The theoretical model presented, validated for other physical systems, demonstrates its functionality also for drug delivery systems, highlighting, in addition, new insights into the complexity of this system. The spatio-temporal scales of system evolution are characterized through the fractality degree, as a measure of the complexity of the phenomena occurring at each scale. Numerical analysis of the experiment showed that the overall drug release kinetics can be obtained by composing "smaller release kinetics" occurring at scales appropriate for each phase of the drug release mechanism, phases whose expansion depends on the system density. Moreover, the uncertainties in establishing the exact limits of the phases were removed by applying the principle of scale superposition, resulting in a global fractality degree corresponding to the entire release kinetics. Even if the theoretical model is perfectible by identifying constants specific to each delivery system, this paper is intended to be the beginning of an alternative approach to drug delivery mechanisms.
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Affiliation(s)
- E S Bacaita
- Department of Physics, "Gheorghe Asachi" Technical University of Iasi, Prof. Dr Docent Dimitrie Mangeron Rd, No. 73, Iasi 700050, Romania.
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