Articles de revues : « Photovoltaics - NCs »

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Mirabella, Salvo, Salvo Cosentino et Antonio Terrasi. « Synthesis and Light Absorption Mechanism in Si or Ge Nanoclusters for Photovoltaics Applications ». Solid State Phenomena 205-206 (octobre 2013) : 465–74. http://dx.doi.org/10.4028/www.scientific.net/ssp.205-206.465.

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Photon absorption in the solar energy range has been investigated in semiconductor nanostructures. Different synthesis techniques (magnetron sputtering, plasma enhanced chemical vapor deposition, ion implantation) followed by thermal annealing, have been employed to fabricate Si or Ge nanoclusters (1-25 nm in size) embedded in SiO2or Si3N4matrices. The thermal evolution in the formation of Si nanoclusters (NCs) in SiO2was shown to depend on the synthesis technique and to significantly affect the light absorption. Experimentally measured values of optical bandgap (EgOPT) in Si NCs evidence the quantum confinement effect which significantly increases the value ofEgOPTin comparison to bulk Si.EgOPTspans over a large range (1.6-2.6 eV) depending on the Si content, on the deposition technique and, in a most significant way, on the structural phase of NC. Amorphous Si NCs have a lowerEgOPTin comparison to crystalline ones. The matrix effect on the synthesis and light absorption in semiconductor NCs was investigated for Ge NCs. Large difference in the Ge NCs synthesis occurred when using SiO2or Si3N4matrices, essentially due to a much lower Ge diffusivity in the latter, which slows down the formation and growth of Ge NCs in comparison to silica matrix. Light absorption in NCs is also shown to be largely affected by the host matrix. Actually, Ge NCs embedded in Si3N4material absorb photons in the solar energy range with a higher efficiency than in silica, due to the different confinement effect. In fact, Si3N4host offers a lower potential barrier to photogenerated carriers in comparison to silica, thus a lower confinement effect is expected, leading to slightly smaller optical bandgap. These effects have been presented and discussed for potential application in light harvesting purposes.

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Kovalenko, Maksym V., Loredana Protesescu et Maryna I. Bodnarchuk. « Properties and potential optoelectronic applications of lead halide perovskite nanocrystals ». Science 358, n^o 6364 (9 novembre 2017) : 745–50. http://dx.doi.org/10.1126/science.aam7093.

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Semiconducting lead halide perovskites (LHPs) have not only become prominent thin-film absorber materials in photovoltaics but have also proven to be disruptive in the field of colloidal semiconductor nanocrystals (NCs). The most important feature of LHP NCs is their so-called defect-tolerance—the apparently benign nature of structural defects, highly abundant in these compounds, with respect to optical and electronic properties. Here, we review the important differences that exist in the chemistry and physics of LHP NCs as compared with more conventional, tetrahedrally bonded, elemental, and binary semiconductor NCs (such as silicon, germanium, cadmium selenide, gallium arsenide, and indium phosphide). We survey the prospects of LHP NCs for optoelectronic applications such as in television displays, light-emitting devices, and solar cells, emphasizing the practical hurdles that remain to be overcome.

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Bastola, Ebin, Kamala Khanal Subedi, Khagendra P. Bhandari et Randy J. Ellingson. « Solution-processed Nanocrystal Based Thin Films as Hole Transport Materials in Cadmium Telluride Photovoltaics ». MRS Advances 3, n^o 41 (2018) : 2441–47. http://dx.doi.org/10.1557/adv.2018.349.

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ABSTRACTThe cadmium telluride (CdTe) photovoltaic (PV) comprise an efficient and cost-effective technology for harvesting solar energy. However, device efficiency remains limited in part by low-open circuit voltage (VOC) and fill factor (FF) due to inefficient transport of photo-generated charge carriers. Given the deep valence band of CdTe, the use of copper/gold (Cu/Au) as a back contact serves primarily to narrow the width of the inherent Schottky junction evident in CdTe solar cells (in our laboratory, Cu/Au has been used as a standard back contact). For efficient transport of carriers to and into the back contact, a hole transport layer (HTL) is desired with valence band edge comparable to that of CdTe (∼ -5.9 eV). Here, we report solution-processed nanocrystal (NCs) based thin films as HTLs in CdTe solar cells. The earth abundant materials we discuss include iron pyrite (FeS2), nickel-alloyed iron pyrite (NixFe1-xS2), zinc copper sulfide (ZnxCu1-xS) nanocomposites, and perovskite-based films. The FeS2 and NixFe1-xS2 NCs are synthesized by a hot-injection route, and thin films are fabricated by drop-casting, and spin-coating techniques using colloidal NCs. ZnxCu1-xS thin films are fabricated by chemical bath deposition. These NC-based thin films are applied and studied as the HTLs in CdTe devices. On using these materials, the device performance can be increased up to 10% compared to the standard Cu/Au back contact. Here, we discuss the benefits, challenges, and opportunities for these back contact materials in CdTe photovoltaics.

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Zaffalon, Matteo L., Valerio Pinchetti, Andrea Camellini, Sergey Vikulov, Chiara Capitani, Bing Bai, Meng Xu et al. « Intrinsic and Extrinsic Exciton Recombination Pathways in AgInS2 Colloidal Nanocrystals ». Energy Material Advances 2021 (5 avril 2021) : 1–10. http://dx.doi.org/10.34133/2021/1959321.

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Ternary I-III-VI2 nanocrystals (NCs), such as AgInS2 and CuInS2, are garnering interest as heavy-metal-free materials for photovoltaics, luminescent solar concentrators, LEDs, and bioimaging. The origin of the emission and absorption properties in this class of NCs is still a subject of debate. Recent theoretical and experimental studies revealed that the characteristic Stokes-shifted and long-lived luminescence of stoichiometric CuInS2 NCs arises from the detailed structure of the valence band featuring two sublevels with different parity. The same valence band substructure is predicted to occur in AgInS2 NCs, yet no experimental confirmation is available to date. Here, we use complementary spectroscopic, spectro-electrochemical, and magneto-optical investigations as a function of temperature to investigate the band structure and the excitonic recombination mechanisms in stoichiometric AgInS2 NCs. Transient transmission measurements reveal the signatures of two subbands with opposite parity, and photoluminescence studies at cryogenic temperatures evidence a dark state emission due to enhanced exchange interaction, consistent with the behavior of stoichiometric CuInS2 NCs. Lowering the temperature as well as applying reducing electrochemical potentials further suppress electron trapping, which represents the main nonradiative channel for exciton decay, leading to nearly 100% emission efficiency.

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Havryliuk, Yevhenii, Volodymyr Dzhagan, Anatolii Karnaukhov, Oleksandr Selyshchev, Julia Hann et Dietrich R. T. Zahn. « Raman Spectroscopy and Thermoelectric Characterization of Composite Thin Films of Cu2ZnSnS4 Nanocrystals Embedded in a Conductive Polymer PEDOT:PSS ». Nanomaterials 13, n^o 1 (22 décembre 2022) : 41. http://dx.doi.org/10.3390/nano13010041.

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Cu2ZnSnS4 (CZTS) is an intensively studied potential solar cell absorber and a promising thermoelectric (TE) material. In the form of colloidal nanocrystals (NCs), it is very convenient to form thin films on various substrates. Here, we investigate composites of CZTS NCs with PEDOT:PSS, a widely used photovoltaics polymer. We focus on the investigation of the structural stability of both NCs and polymers in composite thin films with different NC-to-polymer ratios. We studied both pristine films and those subjected to flash lamp annealing (FLA) or laser irradiation with various power densities. Raman spectroscopy was used as the main characterization technique because the vibrational modes of CZTS NCs and the polymer can be acquired in one spectrum and thus allow the properties of both parts of the composite to be monitored simultaneously. We found that CZTS NCs and PEDOT:PSS mutually influence each other in the composite. The thermoelectric properties of PEDOT:PSS/CZTS composite films were found to be higher compared to the films consisting of bare materials, and they can be further improved by adding DMSO. However, the presence of NCs in the polymer deteriorates its structural stability when subjected to FLA or laser treatment.

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Xu, Ao, Qichuan Huang, Kaiying Luo, Donghuan Qin, Wei Xu, Dan Wang et Lintao Hou. « Efficient Nanocrystal Photovoltaics with PTAA as Hole Transport Layer ». Nanomaterials 12, n^o 17 (3 septembre 2022) : 3067. http://dx.doi.org/10.3390/nano12173067.

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The power conversion efficiency (PCE) of solution-processed CdTe nanocrystals (NCs) solar cells has been significantly promoted in recent years due to the optimization of device design by advanced interface engineering techniques. However, further development of CdTe NC solar cells is still limited by the low open-circuit voltage (Voc) (mostly in range of 0.5–0.7 V), which is mainly attributed to the charge recombination at the CdTe/electrode interface. Herein, we demonstrate a high-efficiency CdTe NCs solar cell by using organic polymer poly[bis(4–phenyl)(2,4,6–trimethylphenyl)amine] (PTAA) as the hole transport layer (HTL) to decrease the interface recombination and enhance the Voc. The solar cell with the architecture of ITO/ZnO/CdS/CdSe/CdTe/PTAA/Au was fabricated via a layer-by-layer solution process. Experimental results show that PTAA offers better back contact for reducing interface resistance than the device without HTL. It is found that a dipole layer is produced between the CdTe NC thin film and the back contact electrode; thus the built–in electric field (Vbi) is reinforced, allowing more efficient carrier separation. By introducing the PTAA HTL in the device, the open–circuit voltage, short-circuit current density and the fill factor are simultaneously improved, leading to a high PCE of 6.95%, which is increased by 30% compared to that of the control device without HTL (5.3%). This work suggests that the widely used PTAA is preferred as the excellent HTL for achieving highly efficient CdTe NC solar cells.

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Sun, Yujian, Yongcao Zhang, Yuxin Li et Yilin Li. « Self-Absorption Analysis of Perovskite-Based Luminescent Solar Concentrators ». Electronic Materials 2, n^o 4 (10 décembre 2021) : 545–52. http://dx.doi.org/10.3390/electronicmat2040039.

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Luminescent solar concentrators (LSCs) are considered promising in their application as building-integrated photovoltaics (BIPVs). However, they suffer from low performance, especially in large-area devices. One of the key issues is the self-absorption of the luminophores. In this report, we focus on the study of self-absorption in perovskite-based LSCs. Perovskite nanocrystals (NCs) are emerging luminophores for LSCs. Studying the self-absorption of perovskite NCs is beneficial to understanding fundamental photon transport properties in perovskite-based LSCs. We analyzed and quantified self-absorption properties of perovskite NCs in an LSC with the dimensions of 6 in × 6 in × 1/4 in (152.4 mm × 152.4 mm × 6.35 mm) using three approaches (i.e., limited illumination, laser excitation, and regional measurements). The results showed that a significant number of self-absorption events occurred within a distance of 2 in (50.8 mm), and the photo surface escape due to the repeated self-absorption was the dominant energy loss mechanism.

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Levchuk, I., C. Würth, F. Krause, A. Osvet, M. Batentschuk, U. Resch-Genger, C. Kolbeck et al. « Industrially scalable and cost-effective Mn2+ doped ZnxCd1−xS/ZnS nanocrystals with 70% photoluminescence quantum yield, as efficient down-shifting materials in photovoltaics ». Energy & ; Environmental Science 9, n^o 3 (2016) : 1083–94. http://dx.doi.org/10.1039/c5ee03165f.

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Arumugam, Gowri Manohari, Santhosh Kumar Karunakaran, Raquel E. Galian et Julia Pérez-Prieto. « Recent Progress in Lanthanide-Doped Inorganic Perovskite Nanocrystals and Nanoheterostructures : A Future Vision of Bioimaging ». Nanomaterials 12, n^o 13 (21 juin 2022) : 2130. http://dx.doi.org/10.3390/nano12132130.

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All-inorganic lead halide perovskite nanocrystals have great potential in optoelectronics and photovoltaics. However, their biological applications have not been explored much owing to their poor stability and shallow penetration depth of ultraviolet (UV) excitation light into tissues. Interestingly, the combination of all-inorganic halide perovskite nanocrystals (IHP NCs) with nanoparticles consisting of lanthanide-doped matrix (Ln NPs, such as NaYF4:Yb,Er NPs) is stable, near-infrared (NIR) excitable and emission tuneable (up-shifting emission), all of them desirable properties for biological applications. In addition, luminescence in inorganic perovskite nanomaterials has recently been sensitized via lanthanide doping. In this review, we discuss the progress of various Ln-doped all-inorganic halide perovskites (LnIHP). The unique properties of nanoheterostructures based on the interaction between IHP NCs and Ln NPs as well as those of LnIHP NCs are also detailed. Moreover, a systematic discussion of basic principles and mechanisms as well as of the recent advancements in bio-imaging based on these materials are presented. Finally, the challenges and future perspectives of bio-imaging based on NIR-triggered sensitized luminescence of IHP NCs are discussed.

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Shan, Feng, et Tong Zhang. « Shape and Size Dependent Light Absorption Enhancement of Silver Nanostructures in Organic Solar Cells ». Solid State Phenomena 266 (octobre 2017) : 90–94. http://dx.doi.org/10.4028/www.scientific.net/ssp.266.90.

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Metal nanoparticles (MNPs) induced light absorption enhancement using for the improvement of power conversion efficiency of organic solar cells (OSCs) is a new research direction in photovoltaics. However, the device performance influence of the shape and size of MNPs has not been well investigated. In this paper, we focused on the comparison study of the optical absorption enhancement between silver nanospheres (Ag-NSs) and silver nanocubes (Ag-NCs) which are embedded in the active layer of OSCs using finite element method (FEM) simulation. Influence of the structural parameters, including the size and shape of nanoparticels, and their relative distance are systematically discussed. The results indicated that the light absorption enhancement employing Ag-NCs is much higher than that of Ag-NSs in the 300–800 nm wavelength range. Meantime, once the distance between the adjacent nanoparticles is well controlled, the optimal absorption enhancement factor of OSCs can be obtained. As the scattering cross-section of Ag-NCs is much higher than that of Ag-NSs over a broad wavelength range, the optimized light enhancement of Ag-NCs reaches 19 % which is 1.26 times higher than that of Ag-NSs.

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Sekerbayev, K. S., G. K. Mussabek, Ye Shabdan et Ye T. Taurbayev. « Ligand Assisted Control of Photoluminescence in Organometal Perovskite Nanocrystals ». Eurasian Chemico-Technological Journal 23, n^o 2 (30 août 2021) : 89. http://dx.doi.org/10.18321/ectj1078.

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Organometal perovskite nanocrystals have shown remarkable properties not only in photovoltaics, but also in light-emitting devices. In this work colloidal nanocrystals of organometal perovskite CH3NH3PbBr3 (MAPBr) with effective visible photoluminescence were synthesized by the ligand assisted reprecipitation method. The studies were carried out by photoluminescence spectroscopy and optical transmission spectroscopy. Analysis of the photoluminescence and transmission spectra showed that by changing the concentration of the ligands oleylamine and octylamine, it is possible to control the size of nanocrystals and the photoluminescence wavelength due to the quantum confinement effect. It was shown that the increase in ligands concentration in MAPBr perovskite nanocrystals (NCs) solutions decreases the width of the peak which indicates a better quality of the obtained nanocrystals. An increase in the band gap indicates a decrease in the size of the nanocrystals. Replacing the ligands in the colloidal perovskite NCs solutions leads to shift of the photoluminescence peak from 456 to 535 nm.

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Kriegel, Ilka, et Francesco Scotognella. « Tunable light filtering by a Bragg mirror/heavily doped semiconducting nanocrystal composite ». Beilstein Journal of Nanotechnology 6 (16 janvier 2015) : 193–200. http://dx.doi.org/10.3762/bjnano.6.18.

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Tunable light filters are critical components for many optical applications in which light in-coupling, out-coupling or rejection is crucial, such as lasing, sensing, photovoltaics and information and communication technology. For this purpose, Bragg mirrors (band-pass filters with high reflectivity) represent good candidates. However, their optical characteristics are determined during the fabrication stage. Heavily doped semiconductor nanocrystals (NCs), on the other hand, deliver a high degree of optical tunability through the active modulation of their carrier density, ultimately influencing their plasmonic absorption properties. Here, we propose the design of an actively tunable light filter composed of a Bragg mirror and a layer of plasmonic semiconductor NCs. We demonstrate that the filtering properties of the coupled device can be tuned to cover a wide range of frequencies from the visible to the near infrared (vis–NIR) spectral region when employing varying carrier densities. As the tunable component, we implemented a dispersion of copper selenide (Cu2−xSe) NCs and a film of indium tin oxide (ITO) NCs, which are known to show optical tunablility with chemical or electrochemical treatments. We utilized the Mie theory to describe the carrier-dependent plasmonic properties of the Cu2−x Se NC dispersion and the effective medium theory to describe the optical characteristics of the ITO film. The transmission properties of the Bragg mirror have been modelled with the transfer matrix method. We foresee ease of experimental realization of the coupled device, where filtering modulation is achieved upon chemical and electrochemical post-fabrication treatment of the heavily doped semiconductor NC component, eventually resulting in tunable transmission properties of the coupled device.

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Hou, Lei, Philippe Tamarat et Brahim Lounis. « Revealing the Exciton Fine Structure in Lead Halide Perovskite Nanocrystals ». Nanomaterials 11, n^o 4 (20 avril 2021) : 1058. http://dx.doi.org/10.3390/nano11041058.

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Lead-halide perovskite nanocrystals (NCs) are attractive nano-building blocks for photovoltaics and optoelectronic devices as well as quantum light sources. Such developments require a better knowledge of the fundamental electronic and optical properties of the band-edge exciton, whose fine structure has long been debated. In this review, we give an overview of recent magneto-optical spectroscopic studies revealing the entire excitonic fine structure and relaxation mechanisms in these materials, using a single-NC approach to get rid of their inhomogeneities in morphology and crystal structure. We highlight the prominent role of the electron-hole exchange interaction in the order and splitting of the bright triplet and dark singlet exciton sublevels and discuss the effects of size, shape anisotropy and dielectric screening on the fine structure. The spectral and temporal manifestations of thermal mixing between bright and dark excitons allows extracting the specific nature and strength of the exciton–phonon coupling, which provides an explanation for their remarkably bright photoluminescence at low temperature although the ground exciton state is optically inactive. We also decipher the spectroscopic characteristics of other charge complexes whose recombination contributes to photoluminescence. With the rich knowledge gained from these experiments, we provide some perspectives on perovskite NCs as quantum light sources.

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Qiao, Fen. « Semiconductor Nanocrystals for Photovoltaic Devices ». Materials Science Forum 852 (avril 2016) : 935–38. http://dx.doi.org/10.4028/www.scientific.net/msf.852.935.

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Recently, photovoltaic devices based on colloidal semiconductor nanocrystals (NCs) have attracted a great interest due to their flexible synthesis with tunable band gaps and shape-dependent optical and electronic properties. However, the surface of NCs typically presents long chain with electrically insulating organic ligands, which hinder the device applications for NCs. So the major challenge of NCs for photovoltaic devices application is to decrease the inter NC space and the height of the tunnel barriers among NCs, therefore increase the transport properties of NCs. In this article, recent development of colloidal semiconductor NCs and possible routes for improving transport properties of colloidal NCs were reviewed. Among those methods, the thermal annealing approach provides a simple and cost-effective way to fabricate superlattice and to decrease the inter-space among NCs, which may be used for the preparation of other nanocrystalline superstructure and functional devices.

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Jiang, Xiaomei, Richard D. Schaller, Sergey B. Lee, Jeffrey M. Pietryga, Victor I. Klimov et Anvar A. Zakhidov. « PbSe nanocrystal/conducting polymer solar cells with an infrared response to 2 micron ». Journal of Materials Research 22, n^o 8 (août 2007) : 2204–10. http://dx.doi.org/10.1557/jmr.2007.0289.

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We investigated the photovoltaic response of nanocomposites made of colloidal, infrared-sensitive, PbSe nanocrystals (NCs) of various sizes and conjugated polymers of either regioregular poly (3-hexylthiophene) (RR-P3HT) or poly- (2-methoxy-5-(2-ethylhexoxy)-1,4-phenylene vinylene) (MEH-PPV). The conduction and valence energy levels of PbSe NCs were determined by cyclic voltammetry and revealed type II heterojunction alignment with respect to energy levels in RR-P3HT for smaller NC sizes. Devices composed of NCs and RR-P3HT show good diode characteristics and sizable photovoltaic response in a spectral range from the ultraviolet to the infrared. Using these materials, we have observed photovoltaic response at wavelengths as far to the infrared as 2 μm (0.6 eV), which is desirable due to potential benefits of carrier multiplication (or multi-exciton generation) from a single junction photovoltaic. Under reverse bias, the devices also exhibit good photodiode responses over the same spectral region.

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Hou, Mingyue, Zhaohua Zhou, Ao Xu, Kening Xiao, Jiakun Li, Donghuan Qin, Wei Xu et Lintao Hou. « Synthesis of Group II-VI Semiconductor Nanocrystals via Phosphine Free Method and Their Application in Solution Processed Photovoltaic Devices ». Nanomaterials 11, n^o 8 (15 août 2021) : 2071. http://dx.doi.org/10.3390/nano11082071.

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Solution-processed CdTe semiconductor nanocrystals (NCs) have exhibited astonishing potential in fabricating low-cost, low materials consumption and highly efficient photovoltaic devices. However, most of the conventional CdTe NCs reported are synthesized through high temperature microemulsion method with high toxic trioctylphosphine tellurite (TOP-Te) or tributylphosphine tellurite (TBP-Te) as tellurium precursor. These hazardous substances used in the fabrication process of CdTe NCs are drawing them back from further application. Herein, we report a phosphine-free method for synthesizing group II-VI semiconductor NCs with alkyl amine and alkyl acid as ligands. Based on various characterizations like UV-vis absorption (UV), transmission electron microscope (TEM), and X-ray diffraction (XRD), among others, the properties of the as-synthesized CdS, CdSe, and CdTe NCs are determined. High-quality semiconductor NCs with easily controlled size and morphology could be fabricated through this phosphine-free method. To further investigate its potential to industrial application, NCs solar cells with device configuration of ITO/ZnO/CdSe/CdTe/Au and ITO/ZnO/CdS/CdTe/Au are fabricated based on NCs synthesized by this method. By optimizing the device fabrication conditions, the champion device exhibited power conversion efficiency (PCE) of 2.28%. This research paves the way for industrial production of low-cost and environmentally friendly NCs photovoltaic devices.

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Cunha, Mara, Gabriel Bernardo, Loic Hilliou, Hartmut Wiggers et Rui N. Pereira. « Morphology Control of Thin P3HT-Si-NCs Composite Films for Hybrid Photovoltaic Cells ». Materials Science Forum 730-732 (novembre 2012) : 227–31. http://dx.doi.org/10.4028/www.scientific.net/msf.730-732.227.

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This work deals with an experimental investigation of the microstructure/morphology of spin-casted composite thin films of poly(3-hexylthiophene) (P3HT) and silicon nanocrystals (Si-NCs), in the weight proportion 1:1, which develop under different deposition conditions. The experimental parameters considered were the following: i) solvent quality; ii) spinning rate; iii) spinning time and iv) solution concentration. The developed morphologies were characterized by means of optical microscopy and X-ray diffraction (XRD) measurements. The present work aims at a) establishing the relationship between processing conditions and resultant morphology and b) defining the most relevant processing parameters that govern and are of significance for the induced morphology.

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Ongul, Fatih, Sureyya Aydin Yuksel, Cagdas Allahverdi, Sinem Bozar, Mehmet Kazici et Serap Gunes. « Influences of CdSe NCs on the photovoltaic parameters of BHJ organic solar cells ». Spectrochimica Acta Part A : Molecular and Biomolecular Spectroscopy 194 (avril 2018) : 50–56. http://dx.doi.org/10.1016/j.saa.2018.01.012.

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Kortshagen, Uwe, Rebeccah Anthony, Ryan Gresback, Zachary Holman, Rebekah Ligman, Chin-Yi Liu, Lorenzo Mangolini et Stephen A. Campbell. « Plasma synthesis of group IV quantum dots for luminescence and photovoltaic applications ». Pure and Applied Chemistry 80, n^o 9 (1 janvier 2008) : 1901–8. http://dx.doi.org/10.1351/pac200880091901.

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The unique ability of nonthermal plasmas to form high-quality nanocrystals (NCs) of covalently bonded semiconductors, including the group IV elements silicon (Si) and germanium (Ge), has been extensively demonstrated over the past few years. Recently, plasma processing was also extended to the surface functionalization of NCs, imparting further functionalities to plasma-produced NCs such as solution-processability or the passivation of electronic surface states. This paper focuses on the synthesis and surface functionalization of Si- and Ge-NCs, and on their application in luminescent and photovoltaic devices.

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Thahe, Asad A., Hazri Bakhtiar, Basant A. Ali, Z. Hassan, Nroiah Bidin, Mohamed Bououdina, M. A. Qaeed et al. « Photophysical performance of radio frequency sputtered Pt/n-PSi/ZnO NCs/Pt photovoltaic photodetectors ». Optical Materials 84 (octobre 2018) : 830–42. http://dx.doi.org/10.1016/j.optmat.2018.08.027.

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Rothemund, Ralph, Susanne Kreuzer, Thomas Fromherz et Wolfgang Jantsch. « Time-Resolved Photocurrent Measurements on PbS Nanocrystal Schottky-Contact Photovoltaic Cells ». Solid State Phenomena 178-179 (août 2011) : 56–60. http://dx.doi.org/10.4028/www.scientific.net/ssp.178-179.56.

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We fabricated and characterized NIR-active Schottky-contact solar cells with PbS nanocrystals (NCs) as the active medium. The photovoltaic e ffect is due to carrier generation in the PbS NCs as proven by the comparison of the spectrally-resolved external quantum effciency of the devices and absorbance spectra of the PbS NCs. The operative regime is extended well beyond the Si bandgap into the infrared spectral region up to 1500 nm limited by our measurement setup. One sun I-V and time-resolved photocurrent measurements help to identify critical solar cell parameters for the further improvement of PbS NC Schottky-contact solar cells.

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Chen, Xiaobo. « Photovoltaic properties of silicon nanocrystals in silicon nitride prepared by ammonia sputtering ». Functional Materials Letters 08, n^o 05 (29 septembre 2015) : 1550052. http://dx.doi.org/10.1142/s1793604715500526.

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In this work, we present an investigation of the photovoltaic properties of low-temperature (700°C annealing temperature) prepared P -doped Silicon nanocrystals ( Si NCs ) in silicon nitride by ammonia sputtering followed by rapid thermal annealing (RTA). We examined how the flow rate of NH3influenced the structural properties of the annealed films by using Raman scattering, grazing incidence X-ray diffraction (GI XRD) and transmission electron microscopy (TEM), it was found that the appropriate flow rate of NH3is 3 sccm. For the sample deposited at the flow rate of 3 sccm, TEM image showed that Si NCs were formed with a mean size about 3.7 nm and the density of ~ 2.1 × 1012cm-2; X-ray photoelectron spectroscopy (XPS) characterization showed the existence of Si – P bonds, indicating effective P doping; the average absorptance of higher than 65% and a significant amount of photocurrent makes it suitable for photoactive. Moreover, the experimental P -doped Si NCs : Si3N4/ p - Si heterojunction solar cell has been fabricated, and the device performance was studied. The photovoltaic device fabricated exhibits an open-circuit voltage (VOC) and a short-circuit current density (JSC) of 470 mV and 3.25 mA/cm2, respectively.

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Sun, Haizhu, Junhu Zhang, Ye Tian, Yang Ning, Hao Zhang, Jie Ju, Delong Li, Shidong Xiang et Bai Yang. « Multifunctional Composites Obtained by Incorporating Nanocrystals into Decorated PVK Polymers ». Journal of Nanomaterials 2007 (2007) : 1–7. http://dx.doi.org/10.1155/2007/38589.

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Poly(vinylcarbazole) (PVK) was decorated with surfactant group to achieve amphiphilic polymer with luminescent property. The composition and properties of the polymers were systematically investigated using FTIR, EA, TGA, UV-Vis, and PL characterizations. Different CdTe nanocrystals (NCs) prepared in aqueous medium were directly transferred to organic phase using the PVK-based polymers. The quantum yield of NCs in the composites had been improved by 50% compared with their parent aqueous solution due to the short distance from carbazole moieties to NCs, which facilitated the Förster resonant energy transfer (FRET) between them. Moreover, efficient electron transfer at the interface of NCs and polymers had been confirmed which also indicated the application in photovoltaic cell for such composites.

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Gao, Yu Ping, et Dong Huan Qin. « The Synthesis of High Yield PbS Nanocrystalline and its Photovoltaic Applications ». Advanced Materials Research 924 (avril 2014) : 325–28. http://dx.doi.org/10.4028/www.scientific.net/amr.924.325.

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High quality PbS nanorcrystallines (NCs) have been fabricated in high yield by a simple hydrothermal method using unique ligands. We find that the experiment conditions such as different ligands,the reaction temperature greatly influence the morphology and the size of PbS NCs. Specifically, the complex ligands OPA and butylamine have great effects on the final products compared with no ligand. We can obtain PbS nanocrystalline with more homogeneous size and higher optical properties. On the other hand, higher external quantum efficiency (EQE) of the solar cell will be achieved with Schottky device structure of ITO/PbS/Al.

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Lima, Paulo De Tarso Dantas, Manoel Mariano Neto et Raphael Abrahão. « Análise dos processos de avaliação de impacto ambiental em usinas fotovoltaicas no Nordeste do Brasil ». Revista Brasileira de Geografia Física 15, n^o 3 (13 juin 2022) : 1260. http://dx.doi.org/10.26848/rbgf.v15.3.p1260-1273.

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A geração de eletricidade por sistemas fotovoltaicos vem crescendo exponencialmente em todo o mundo. A implantação desse tipo de atividade requer a elaboração de diversos estudos, dentre eles, a Avaliação de Impacto Ambiental (AIA). Logo, é imperativo o aperfeiçoamento dessa ferramenta, por ser o principal instrumento para a promoção do desenvolvimento sustentável no segmento. Desta forma, este trabalho tem por objetivo identificar os impactos benéficos e adversos, decorrentes da geração de energia fotovoltaica, a partir da organização temporal das avaliações de impacto ambiental, elaboradas no Nordeste brasileiro, no período de 2012 a 2019. Para tanto, empregou-se a análise documental de 41 Estudos de Impacto Ambiental, permitindo identificar 3.381 impactos, subdivididos nas fases de planejamento, implantação, operação e desativação dos projetos. Verificou-se que 75% dos impactos são previstos para ocorrer ao longo da implantação dos empreendimentos. Ao analisar os compartimentos ambientais, percebe-se que 82% e 76,5% dos impactos incidentes sobre os meios bióticos e abióticos, respectivamente, são negativos. Já no meio socioeconômico, 72,2% se mostram positivos. A quantificação histórica dos impactos ambientais pode ser utilizada para avaliar o benefício da atividade nas cidades e regiões, e, pontuar os impactos de maior relevância. Também foi possível identificar que alguns impactos referenciados na literatura internacional não estão previstos nas avaliações de impacto ambiental no Brasil, fato que pode comprometer a tomada de decisão por parte do poder público.Palavras-chave: estudo de impacto ambiental, energia fotovoltaica, energia solar. Analysis of environmental impact assessment processes in photovoltaic power plants in Northeast Brazil A B S T R A C TElectricity generation by photovoltaic systems has been growing exponentially all over the world. The implementation of this type of activity requires the preparation of several studies, including the Environmental Impact Assessment (EIA). Therefore, it is imperative to improve this tool, as it is the main instrument in ensuring the promotion of sustainable development in the segment. Thus, this work aims to identify the beneficial and adverse impacts arising from the generation of photovoltaic energy, based on the temporal organization of environmental impact assessments, prepared in the Brazilian Northeast, in the period 2012 to 2019. the documentary analysis of 41 Environmental Impact Studies, allowing the identification of 3,381 impacts, subdivided into the planning, implementation, operation and deactivation phases of the projects. It was found that 75% of the impacts are expected to occur during the implementation of the projects. When analyzing the environmental compartments, it is noticed that 82% and 76.5% of the impacts incident on biotic and abiotic environments, respectively, are negative. In the socioeconomic environment, 72.2% are positive. The historical quantification of environmental impacts can be used to assess the benefit of the activity in cities and regions, and to score the most relevant impacts. It was also possible to identify that some impacts referenced in the international literature are not foreseen in environmental impact assessments in Brazil, a fact that can compromise decision-making by the government.Keywords: environmental impact study, photovoltaics, solar energy.

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Frieiro, J. L., J. López-Vidrier, O. Blázquez, J. Ibáñez, D. Yazıcıoğlu, S. Gutsch, M. Zacharias, B. Garrido et S. Hernández. « Electroforming of Si NCs/p-Si photovoltaic devices : Enhancement of the conversion efficiency through resistive switching ». Solar Energy Materials and Solar Cells 230 (septembre 2021) : 111252. http://dx.doi.org/10.1016/j.solmat.2021.111252.

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Islam, Ashraful, Surya Prakash Singh, Masatoshi Yanagida, Mohammad Rezaul Karim et Liyuan Han. « Amphiphilic Ruthenium(II) Terpyridine Sensitizers with Long Alkyl Chain Substituted β-Diketonato Ligands : An Efficient Coadsorbent-Free Dye-Sensitized Solar Cells ». International Journal of Photoenergy 2011 (2011) : 1–7. http://dx.doi.org/10.1155/2011/757421.

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Three alkyl-substitutedβ-diketonato-ruthenium(II)-polypyridyl sensitizers with different alkyl chain lengths, [Ru(tctpy)(tfpd)(NCS)] (A1), [Ru(tctpy)(tfdd)(NCS)] (A2), and [Ru(tctpy)(tfid)(NCS)] (A3), were designed and synthesized for dye-sensitized solar cells (DSCs) to investigate the effect of bulky alkyl chain substituents on the photovoltaic performances (where tctpy = 4,4′,4′′-tricarboxy-2,2′:;6′,2′′-terpyridine, tfpd =1,1,1-trifluoropentane-2,4-dione, tfdd = 1,1,1-trifluorodecane-2,4-dione, and tfid =1,1,1-trifluoroicosane-2,4-dione). These complexes exhibit a broad metal-to-ligand charge transfer absorption band over the whole visible range extending up to 950 nm. All complexes were examined in the presence and absence of the coadsorbent deoxycholic acid (DCA) in dye-bath solutions. These sensitizers, when anchored to nanocrystalline TiO2films, achieve efficient sensitization to TiO2electrodes. Under standard AM 1.5 sunlight, the complexA3containing long alkyl chain length of C16yielded a short-circuit photocurrent density of 18.0 mA/cm2, an open-circuit voltage of 0.64 V, and a fill factor of 0.66, corresponding to an overall conversion efficiency of 7.6% in the absence of DCA. The power conversion efficiency ofA1sensitized DSCs was significantly increased upon the addition of DCA as compared to that in the absence of DCA. However, the photovoltaic performance ofA3was not dependent on DCA at all, probably due to the inherent structural nature of theA3molecule.

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Chung, Shu-Ru, Hong-Shuo Chen, Chen-Yu Chien, Meng-Yi Bai et Kuan-Wen Wang. « The Promotion of the Efficiency of Organic Photovoltaic Devices by Addition of Anisotropic CdSe Nanocrystals ». International Journal of Photoenergy 2014 (2014) : 1–8. http://dx.doi.org/10.1155/2014/219123.

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CdSe nanocrystals (NCs) with different morphologies have been synthesized and applied as the acceptor in the active layer of the organic photovoltaic (OPV) devices. CdSe tetrapod (TP)/nanorod (NR) with zinc-blended seeds and wurtzite arms is prepared by seed growth method and mixed with poly(3-hexylthiophene) (P3HT): [6,6]-phenyl-C61-butyric acid methyl ester (PCBM). When the concentrations of CdSe in P3HT: PCBM system are 50 wt% optimally, the efficiency can be promoted about 4.3%, suggesting that an enhancement of 13.2% can be obtained and the addition of anisotropic CdSe NCs content in the active layer can be beneficial for the transport of electrons and light absorption in the OPV devices.

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CHEN, XIAOBO, YU TANG et JIABO HAO. « SPUTTER-GROWN Sb-DOPED SILICON NANOCRYSTALS EMBEDDED IN SILICON-RICH CARBIDE FOR Si HETEROJUNCTION SOLAR CELLS ». Surface Review and Letters 25, n^o 03 (8 mars 2018) : 1850068. http://dx.doi.org/10.1142/s0218625x18500683.

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Sb-doped silicon nanocrystals (Si–NCs) films were fabricated by magnetron co-sputtering combined with rapid-thermal annealing. The effects of Sb content on the structural and electrical properties of the films were studied. The dot size increased with the increasing Sb content, and could be correlated to the effect of Sb-induced crystallization. The variation in the concentration of Sb shows a significant impact on the film properties, where as doped with 0.8[Formula: see text]at.% of Sb exhibited major property improvements when compared with other films. By employing Sb-doped Si–NCs films as emitter layers, Si–NCs/monocrystalline silicon heterojunction solar cells were fabricated and the effect of the Sb doping concentration on the photovoltaic properties was studied. It is found that the doping level in the Si–NCs layer is a key factor in determining the short-circuit current density and power conversion efficiency (PCE). With an optimized doping concentration of 0.8[Formula: see text]at.% of Sb, a maximal PCE of 7.10% was obtained. This study indicates that the Sb-doped Si–NCs can be good candidates for all-silicon tandem solar cells.

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Švrček, Vladimir, et Davide Mariotti. « Electronic interactions of silicon nanocrystals and nanocarbon materials : Hybrid solar cells ». Pure and Applied Chemistry 84, n^o 12 (3 juillet 2012) : 2629–39. http://dx.doi.org/10.1351/pac-con-12-01-12.

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Hybrid inorganic/nanocarbon solar cells represent low-cost solutions for the large-scale manufacturing of energy conversion devices. Here we discuss results that relate to the electronic interactions of nanocarbon materials with freestanding and surfactant-free silicon nanocrystals (Si-ncs) with quantum confinement effects, integrated in bulk-heterojunction solar cells. In particular, we demonstrate the feasibility of bulk-heterojunction photovoltaic solar cells that consist of Si-ncs combined with fullerenes or with semiconducting single-walled carbon nanotubes (SWCNTs). We show that the energy levels between Si-ncs with energy gap exceeding 1.75 eV and fullerenes are adequate for exciton dissociation and carriers (electrons/holes) generation and that hybrid solar cells formed by Si-ncs and semi-conducting SWCNTs favor exciton dissociation only when a distinct chiral index [i.e., (7,5)] is used. While fullerenes show energy conversion capabilities in the visible spectral region (1.7–3.1 eV), the cells containing the SWCNTs, in comparison, have a considerably expanded optical response covering a broad range of the spectrum (0.9–3.1 eV).

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Song, Jing, Xiaoxia Xu, Jihuai Wu et Zhang Lan. « Low-temperature solution-processing high quality Nb-doped SnO2 nanocrystals-based electron transport layers for efficient planar perovskite solar cells ». Functional Materials Letters 12, n^o 01 (21 janvier 2019) : 1850091. http://dx.doi.org/10.1142/s1793604718500911.

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Low-temperature solution-processing method is a kind of low-energy-consuming and simple methodology for preparing cost-effective planar perovskite solar cells (PSCs). To achieve high-effciency planar PSCs, the quality of electron-transporting layers (ETLs) play a key role. The solvothermal-synthesized organic ligands capped semiconductor nanocrystals (NCs) not only have high crystallinity but also show excellent film-formation. Nevertheless, the biggest problem is that these organic ligands will form insulating barriers around the NCs, which will seriously hinder electronic coupling and limit performance of the corresponding devices. Therefore, the stripping treatment for organic ligands, which is not only complex but also has destructive influence on the quality of films, is traditionally used for achieving good performance. Here, we select high crystalline oleic acid-capped SnO2 NCs to prepare ETLs with low-temperature solution-processed methodology without complex ligand stripping step. We use Nb[Formula: see text] doping route to further enhance photovoltaic performance of the planar PSCs. The champion PSC based on Nb-doped SnO2 NCs ETL achieves a power conversion efficiency of 20.07%.

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Amargós-Reyes, Olivia, José-Luis Maldonado, Omar Martínez-Alvarez, María-Elena Nicho, José Santos-Cruz, Juan Nicasio-Collazo, Irving Caballero-Quintana et Concepción Arenas-Arrocena. « Nontoxic pyrite iron sulfide nanocrystals as second electron acceptor in PTB7:PC71BM-based organic photovoltaic cells ». Beilstein Journal of Nanotechnology 10 (14 novembre 2019) : 2238–50. http://dx.doi.org/10.3762/bjnano.10.216.

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Herein, we report the synthesis of nontoxic pyrite iron sulfide (FeS2) nanocrystals (NCs) using a two-pot method. Moreover, we study the influence of these NCs incorporated into the PTB7:PC71BM active layer of bulk-heterojunction ternary organic photovoltaic (OPV) cells. The OPV devices are fabricated with the direct configuration glass/ITO/PEDOT:PSS/PTB7:PC71BM:FeS2/PFN/FM. The Field’s metal (FM) is a eutectic alloy composed of 32.5% Bi, 51% In and 16.5% Sn by weight that melts at 62 °C. It is deposited on the active layer/PFN under atmospheric conditions. Ternary active layers are prepared by adding small amounts of the semiconducting FeS2 NCs at different weight ratios of 0.0, 0.25, 0.5, and 1.0 wt % with respect to the electron donor PTB7. With respect to the reference device (without FeS2), a 21% increase in the power conversion efficiency (PCE) is observed for OPVs with 0.5 wt % FeS2, such that the PCE of the OPVs is enhanced from 5.69 to 6.47%. According to the Kruskal–Wallis and Mann–Whitney statistical tests, all OPV devices follow the same trend.

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Liu, Albert, Diogo B. Almeida, Luiz G. Bonato, Gabriel Nagamine, Luiz F. Zagonel, Ana F. Nogueira, Lazaro A. Padilha et S. T. Cundiff. « Multidimensional coherent spectroscopy reveals triplet state coherences in cesium lead-halide perovskite nanocrystals ». Science Advances 7, n^o 1 (janvier 2021) : eabb3594. http://dx.doi.org/10.1126/sciadv.abb3594.

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Advances in optoelectronics require materials with novel and engineered characteristics. A class of materials that has garnered tremendous interest is metal-halide perovskites, stimulated by meteoric increases in photovoltaic efficiencies of perovskite solar cells. In addition, recent advances have applied perovskite nanocrystals (NCs) in light-emitting devices. It was found recently that, for cesium lead-halide perovskite NCs, their unusually efficient light emission may be due to a unique excitonic fine structure composed of three bright triplet states that minimally interact with a proximal dark singlet state. To study this fine structure without isolating single NCs, we use multidimensional coherent spectroscopy at cryogenic temperatures to reveal coherences involving triplet states of a CsPbI3 NC ensemble. Picosecond time scale dephasing times are measured for both triplet and inter-triplet coherences, from which we infer a unique exciton fine structure level ordering composed of a dark state energetically positioned within the bright triplet manifold.

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Yu, Yang, Wei Zhou, Cheng Li, Peigeng Han, Hui Li et Kun Zhao. « Tb3+ and Bi3+ Co-Doping of Lead-Free Cs2NaInCl6 Double Perovskite Nanocrystals for Tailoring Optical Properties ». Nanomaterials 13, n^o 3 (29 janvier 2023) : 549. http://dx.doi.org/10.3390/nano13030549.

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Lead halide perovskites have achieved remarkable success in various photovoltaic and optoelectronic applications, especially solar cells and light-emitting diodes (LEDs). Despite the significant advances of lead halide perovskites, lead toxicity and insufficient stability limit their commercialization. Lead-free double perovskites (DPs) are potential materials to address these issues because of their non-toxicity and high stability. By doping DP nanocrystals (NCs) with lanthanide ions (Ln3+), it is possible to make them more stable and impart their optical properties. In this work, a variable temperature hot injection method is used to synthesize lead-free Tb3+-doped Cs2NaInCl6 DP NCs, which exhibit a major narrow green photoluminescence (PL) peak at 544 nm derived from the transition of Tb3+ 5D4→7F5. With further Bi3+ co-doping, the Tb3+-Bi3+-co-doped Cs2NaInCl6 DP NCs are not only directly excited at 280 nm but are also excited at 310 nm and 342 nm. The latter have a higher PL intensity because partial Tb3+ ions are excited through more efficient energy transfer channels from the Bi3+ to the Tb3+ ions. The investigation of the underlying mechanism between the intrinsic emission of Cs2NaInCl6 NCs and the narrow green PL caused by lanthanide ion doping in this paper will facilitate the development of lead-free halide perovskite NCs.

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Amaro, Augusto Anselmo, Guilherme Rodrigues da Silva Mattos, Marcos Vinicius de Morais Nishimura, Jessica Dipold, Niklaus Ursus Wetter et Luciana Reyes Pires Kassab. « Silver Nanoclusters Tunable Visible Emission and Energy Transfer to Yb3+ Ions in Co-Doped GeO2-PbO Glasses for Photonic Applications ». Nanomaterials 13, n^o 7 (25 mars 2023) : 1177. http://dx.doi.org/10.3390/nano13071177.

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This work investigates the optical properties of Yb3+ ions doped GeO2-PbO glasses containing Ag nanoclusters (NCs), produced by the melt-quenching technique. The lack in the literature regarding the energy transfer (ET) between these species in these glasses motivated the present work. Tunable visible emission occurs from blue to orange depending on the Yb3+ concentration which affects the size of the Ag NCs, as observed by transmission electron microscopy. The ET mechanism from Ag NCs to Yb3+ ions (2F7/2 → 2F5/2) was attributed to the S1→T1 decay (spin-forbidden electronic transition between singlet–triplet states) and was corroborated by fast and slow lifetime decrease (at 550 nm) of Ag NCs and photoluminescence (PL) growth at 980 nm, for excitations at 355 and 405 nm. The sample with the highest Yb3+ concentration exhibits the highest PL growth under 355 nm excitation, whereas at 410 nm it is the sample with the lowest concentration. The restriction of Yb3+ ions to the growth of NCs is responsible for these effects. Thus, higher Yb3+ concentration forms smaller Ag NCs, whose excitation at 355 nm leads to more efficient ET to Yb3+ ions compared to 410 nm. These findings have potential applications in the visible to near-infrared regions, such as tunable CW laser sources and photovoltaic devices.

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Zeevi, Gilad, Joanna Dehnel, Adam K. Budniak, Yana Milyutin, Guy Ankonina, Hossam Haick, Efrat Lifshitz et Yuval E. Yaish. « Dynamics of light-induced charge transfer between carbon nanotube and CdSe/CdS core/shell nanocrystals ». Nano Futures 6, n^o 1 (20 janvier 2022) : 015001. http://dx.doi.org/10.1088/2399-1984/ac3ccc.

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Abstract The integration of semiconducting colloidal nanocrystals (NCs) with carbon nanotubes (CNTs) in a single device presents a unique platform that combines optical flexibility with high charge carrying capability. These qualities are desirable in many applications such as photovoltaic cells, photocatalysis, and light sensors. Here, we present hybrid devices that incorporate various CdSe/CdS core/shell NCs, such as seeded quantum dots and asymmetric seeded nanorods (a-sNRs), with a single-wall CNT in a field-effect transistor geometry. We used electrical measurements to probe a light-induced charge transfer (LICT) between the CdSe/CdS NCs and the CNT. We investigate the effect of gate voltage on the LICT magnitude and temporal characteristics. Surprisingly, the measured photo-response depends on the gate voltage, and we observe both electrons and holes transfer from the a-sNRs to the CNT. Furthermore, a comparison between LICT measurements on different devices with different CNTs and NC types reveals that the charge transfer time is directly proportional to the shell-thickness around the CdSe core and inversely correlated with the NCs size. The recovery of the charge trapped inside the CdSe/CdS NCs is characterized by two distinct fast and slow relaxation times, which depend on the NCs size and CNT type. Although, the charge relaxation time is similar between the symmetric QDs and the asymmetric sNRs, the overall percentage of the remaining charge in the QDs is significantly larger than in the sNRs. Understanding both gate voltage and NCs size effect on the LICT processes can optimize the performance of optoelectronic devices.

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Taylan, Gozde, Onur Taylan et Murat Fahrioglu. « Comparison of Middle-Sized PTC and PV Power Plants for METU NCC ». World Journal of Environmental Research 8, n^o 2 (31 décembre 2018) : 53–59. http://dx.doi.org/10.18844/wjer.v8i2.4126.

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Since usage of fossil fuels for producing electricity causes climate change, renewable energy options have become one of the best substitution for fossil fuels. Solar energy promises high amount of resources for producing electricity. Among solar energy alternatives, Photovoltaic (PV) and Parabolic Trough Collectors (PTC) are dominant in the market. This paper compares middle size of PV and PTC power plant for the electricity need of Middle East Technical University Northern Cyprus Campus. Based on the maximum hourly demand of METU NCC, both PV and PTC are sized to 3 MWe. The simulations were performed via SAM software using the hourly values from typical meteorological data, which include solar irradiation, wind speed, dry and wet bulb temperatures, relative humidity and pressure. For the PTC and PV plants, commercially available components are used. The scenario assumes METU NCC to be a grid-connected micro-grid with one-way tariff, so that any deficit energy can be met by the utility and any excess energy produced by the suggested renewable energy systems will be given to the grid for free. The results indicate that 3 MW PV plant would generate annual energy of about 4.95 GWh with a capacity factor of 18.9%. These numbers would yield to a LCOE value of 2.60 ¢/kWh. On the other hand, the suggested 3 MW PTC plant with 2 solar multiple would supply about annual energy of 6.3 GWh at a capacity factor of 24.0%. The LCOE of the energy from PTC plant was estimated to be 8.47 ¢/kWh due to high capital and operation cost of PTC plants compared to PV plants. However, over years the cost of PTC power plants has been decreasing. Additionally, both PTC plant and PV plant would consume water only for cleaning purposes that makes them suitable for Cyprus water scarcity conditions. Overall, this study shows pros and cons of middle-sized PV and PTC plants with the case study of METU NCC. Keywords: economic comparison, levelized cost of energy, parabolic trough, photovoltaic, renewable energy, solar energy

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Marandi, M., et F. S. Mirahmadi. « Aqueous synthesis of the CdTe NCs and influence of size on photovoltaic performance of the CdS/CdTe co-sensitized solar cells ». Journal of Alloys and Compounds 800 (septembre 2019) : 140–49. http://dx.doi.org/10.1016/j.jallcom.2019.06.025.

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Mohanta, Kallol, Yasser Attia Attia, David Buceta, Ángel M. Pérez-Mariño, M. Carmen Blanco Varela, M. Arturo López-Quintela et José Rivas. « Electrochemical study of UV erosion of Au nanorods by silver nanoclusters (NCs) allows the construction of a NC-sensitized photovoltaic cell ». Applied Nanoscience 8, n^o 7 (14 juillet 2018) : 1641–48. http://dx.doi.org/10.1007/s13204-018-0840-7.

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Fanizza, Elisabetta, Roberto Schingo, Annamaria Panniello, Angelica Maria Lanza, Nicoletta Depalo, Angela Agostiano, Maria Lucia Curri et Marinella Striccoli. « CsPbBr3 Nanocrystals-Based Polymer Nanocomposite Films : Effect of Polymer on Spectroscopic Properties and Moisture Tolerance ». Energies 13, n^o 24 (20 décembre 2020) : 6730. http://dx.doi.org/10.3390/en13246730.

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Metal halide perovskites nanocrystals (NCs) represent an emerging class of materials that find increasing application in optoelectronic and photovoltaic devices, thanks to their intriguing optical properties, including high absorption coefficient, high fluorescence quantum yield (PL QY) and fast charge carrier separation. However, their opening to market is still hindered by their limited reliability, due to an intrinsic structural instability and degradation of their photophysical properties upon air, moisture, and light exposure. The incorporation of perovskite NCs in polymer matrix can limit some of the NC instability issues, with advantages in film processability, device fabrication and mechanical performance, being also useful for fundamental studies. In this regard, here, nanocomposites based on polymethylmethacrylate or polystyrene embedding all-inorganic CsPbBr3 NCs have been prepared and processed in the form of flexible free-standing films. A systematic spectrofluorimetric study, comprising steady state photoluminescence (PL), PL quantum yield (QY) and PL decay of the free-standing films before and after exposure to relative humidity condition (RH% 85%, at 25 °C) is performed and discussed. Phase segregation phenomena, changes in NC passivation and recombination dynamics are evaluated as a function of polymer loading and its molecular structure and finally the efficacy of the polymer as moisture barrier investigated.

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Mkawi, E. M., Y. Al-Hadeethi, R. S. Bazuhair, A. S. Yousef, E. Shalaan, B. Arkook, A. M. Abdeldaiem, Rahma Almalki et E. Bekyarova. « Optimization of Sb2S3 Nanocrystal Concentrations in P3HT : PCBM Layers to Improve the Performance of Polymer Solar Cells ». Polymers 13, n^o 13 (29 juin 2021) : 2152. http://dx.doi.org/10.3390/polym13132152.

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In this study, polymer solar cells were synthesized by adding Sb2S3 nanocrystals (NCs) to thin blended films with polymer poly(3-hexylthiophene)(P3HT) and [6,6]-phenyl-C61-butyric-acid-methyl-ester (PCBM) as the p-type material prepared via the spin-coating method. The purpose of this study is to investigate the dependence of polymer solar cells’ performance on the concentration of Sb2S3 nanocrystals. The effect of the Sb2S3 nanocrystal concentrations (0.01, 0.02, 0.03, and 0.04 mg/mL) in the polymer’s active layer was determined using different characterization techniques. X-ray diffraction (XRD) displayed doped ratio dependences of P3HT crystallite orientations of P3HT crystallites inside a block polymer film. Introducing Sb2S3 NCs increased the light harvesting and regulated the energy levels, improving the electronic parameters. Considerable photoluminescence quenching was observed due to additional excited electron pathways through the Sb2S3 NCs. A UV–visible absorption spectra measurement showed the relationship between the optoelectronic properties and improved surface morphology, and this enhancement was detected by a red shift in the absorption spectrum. The absorber layer’s doping concentration played a definitive role in improving the device’s performance. Using a 0.04 mg/mL doping concentration, a solar cell device with a glass /ITO/PEDOT:PSS/P3HT-PCBM: Sb2S3:NC/MoO3/Ag structure achieved a maximum power conversion efficiency of 2.72%. These Sb2S3 NCs obtained by solvothermal fabrication blended with a P3HT: PCBM polymer, would pave the way for a more effective design of organic photovoltaic devices.

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Wang, Yijie, Yingxiu Li, Zhirang Guo, Wei Liu, Rui Zhang, Liang Chu et Xing’ao Li. « Ethanol addition for morphology regulation of TiO2 nanorod arrays towards efficient hole-conductor-free perovskite solar cells ». Functional Materials Letters 11, n^o 04 (août 2018) : 1850080. http://dx.doi.org/10.1142/s1793604718500807.

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TiO2 nanorod arrays (NAs) were synthesized with different morphology based on ethanol addition in the TiO2 precursors for efficient hole-conductor-free perovskite solar cells (PSCs). The morphology and optical properties of samples based on TiO2 NAs prepared with a different amount of ethanol added in TiO2 precursors were analyzed. The results indicated that ethanol addition in TiO2 precursors help regulate the morphology of TiO2 NAs and improve the photovoltaic performance of the PSCs based on TiO2 NAs. Finally, the carbon-based PSCs with 96[Formula: see text]nm TiO2 NAs in diameter by 1[Formula: see text]mL of ethanol addition achieved the optimal performance with a power conversion efficiency (PCE) of 11.86%. The results can offer inspiration for performance improvement of PSCs based on TiO2 NAs.

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Qazi, Umair Yaqub. « Silver Nanoparticles Formation by Nanosecond Pulsed Laser Irradiation in an Aqueous Solution of Silver Nitrate ; Effect of Sodium bis (2-ethyl hexyl) Sulfosuccinate ». Journal of New Materials for Electrochemical Systems 24, n^o 1 (31 mars 2021) : 38–42. http://dx.doi.org/10.14447/jnmes.v24i1.a07.

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A photochemical reduction of a silver salt precursor using near-ultra-violet (UV) pulsed laser (355 nm) irradiation into aqueous surfactant sodium-bis (2–ethylhexyl) sulfosuccinate (AOT) solution has succeeded in synthesizing homogenous speculative silver nanoparticles (Ag NPs). Without using any additive, the irradiation from ns laser pulses to aqueous silver nitrate solution was observed to create nanocubes (NCs). The photoproduct was transformed into a nanosphere when irradiated with a particular AOT concentration. The photoproduct concentration of NCs to NSs was approximately ten times lower than the critical concentration of micellar (CMC) in AOT, which means that the growth of NSs was aided in a single layer of AOT adsorbed on silver surfaces. A UV / Visible Spectrophotometer and Transmission/Scanning electron microscopy (TEM/SEM) were used to characterize the photochemically synthesized sample thoroughly. The mean size of AgNSs, analyzed by TEM, was 8 nm. These parameters have shown the growth of AgNSs and discussed in the paper. These nanoparticles are potential candidates for catalyst, semiconductor, photovoltaic equipment, medical diagnostics applications than bulk materials.

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Nada, Amr A., Hanaa Selim et Mikhael Bechelany. « A novel photoelectrode of NiO@ZnO nanocomposite prepared by Pechini method coupled with PLD for efficiency enhancement in DSSCs ». Materials Science-Poland 36, n^o 2 (25 juin 2018) : 327–36. http://dx.doi.org/10.1515/msp-2018-0045.

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Abstract The dye-sensitized solar cells made of NiO@ZnO nanoparticles were synthesized by a novel Pechini route using different NiO molar concentration ratios. The thermal, structural morphological, optical and electrical properties of the prepared samples were investigated using thermal gravimetric analysis and differential scanning calorimetery (TGA/DSC), X-ray diffraction (XRD), high-resolution transmission electron microscopy (HR-TEM), FT-IR and Raman spectroscopy, UV-diffuse reflectance (UV-DRS), photoluminescence (PL) and current-voltage (I-V) measurements. The success of doping process was confirmed by the XRD patterns, which revealed the existence of new peak at 43.2° corresponding to secondary phase NiO. UV spectra exhibited red shifts in NiO doped ZnO NCs and PL spectra showed strong emission band at 355 nm. The doping of ZnO with NiO was intended to enhance the surface defects of ZnO. The current-voltage measurements showed an improvement of the short circuit photocurrent (Jsc) and fill factor (FF) and a decrease in the open circuit voltage (VOC) for dye-sensitized solar cell (DSSC) based on NiO-ZnO NCs. A clear enhancement in efficiency of DSSC from 1.26±0.10 % for pure ZnO to 3.01±0.25 % for NiO-ZnO NCs at the optimum doping with 1.5 mol% of NiO to ZnO (ZN1.5) was observed. The obtained material can be a suitable candidate for photovoltaic applications.

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Kumar, Ashish, S. S. Rawat, Sanjay Kumar Swami, Vidya Nand Singh et Ritu Srivastava. « Benzoyl Halide as Alternative Precursor for Synthesis of Lead Free Double Perovskite Cs3Bi2Br9 Nanocrystals ». Journal of Nanoscience and Nanotechnology 20, n^o 6 (1 juin 2020) : 3802–8. http://dx.doi.org/10.1166/jnn.2020.17495.

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Ternary bismuth halides are interesting functional materials closely related to Pb halide perovskite photovoltaic material, and are widely sought after due to reduced toxicity of Bi compared to Pb. There are several reports on synthesis of Cs3Bi2Br9 nanocrystals (NCs) due to its being relatively stable compared to lead perovskite. Cs3Bi2Br9 nanocrystals have been synthesised using benzoyl bromide as an precursor using hot injection process at two different temperatures of 120 °C and 160 °C. Samples have been characterized for its structural, optical, microstructural and luminescent properties using X-ray diffraction, (XRD) UV-Vis spectroscopy, high resolution transmission electron microscopy and photoluminescent spectroscopy. XRD showed formation of Cs3Bi2Br9 phase with mono-crystalline structure. UV-Vis showed two types of band gap in the visible region which shows that the material can be used for photovoltaic applications. HRTEM confined the particles to be composed of nanocrystals with ˜5 nm particles in the samples grown at 120 °C and it the particles joined together yield various structures composed of nanoparticles. The time resolved photoluminescence shows average life times of 3.067 ns and 4.761 ns for samples grown at two different temperatures. To the best of our knowledge, this is the first report where benzoyl halide has been used as alternative precursor for the synthesis of lead free double perovskite Cs3Bi2Br9 nanocrystals which have many applications.

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Nguyen, Phuong Tuyet, Binh Xuan Thi Lam, Anders Rand Andersen, Poul Erik Hansen et Torben Lund. « Photovoltaic Performance and Characteristics of Dye-Sensitized Solar Cells Prepared with the N719 Thermal Degradation Products [Ru(LH)2(NCS)(4-tert-butylpyridine)][N(Bu)4] and [Ru(LH)2(NCS)(1-methylbenzimidazole)][N(Bu)4] ». European Journal of Inorganic Chemistry 2011, n^o 16 (26 avril 2011) : 2533–39. http://dx.doi.org/10.1002/ejic.201000935.

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Silva, Angélica da, Marcelo Felisberto de Lima, Fernando Pinto Coelho et Agnaldo José dos Santos. « Energia solar fotovoltaica : estudo da diversificação da matriz energética brasileira com a inserção de usinas fotovoltaicas na superfície das represas das hidrelétricas ». ForScience 10, n^o 1 (4 juillet 2022) : e00764. http://dx.doi.org/10.29069/forscience.2022v10n1.e764.

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Este artigo mostra a viabilidade da implementação de usinas solares flutuantes no Brasil. A ampliação das usinas já existentes nas superfícies dos lagos das hidrelétricas pode ser utilizada para geração de mais energia fotovoltaica. O aspecto metodológico enfatiza a obtenção de dados da irradiação solar, envolvendo a geração de energia por sistemas fotovoltaicos e de hidrelétricas, o potencial solar do Brasil para implantação de sistemas flutuantes. Uma análisenumérica da potência de usinas solares sobre as represas das usinas hidrelétricas de Sobradinho e de Tucuruí foi realizada, com isso é visto que a energia gerada supriria 91,21% da potência nacional que é de 180 GW. A aplicação desses resultados sugere a diversificação da matriz energética brasileira. Palavras-chave: Energia Solar. Usinas Flutuantes. Usinas Hidrelétricas. Rio São Francisco. Solar photovoltaic energy: study of diversification of the brazilian energy matrix with insert of photovoltaic plants on the lakes surfaces of hydrelectric reservoirs Abstract This article shows the viability of the floating solar plants implatation in Brazil. The enlargement of the existing plants on the hydrelectric lakes surfaces can be utilized to generate more photovoltaic energy. The methodological aspect emphasizes the obtation of solar irradiation data, to involve the energy generation by photovoltaic system, hydrelectric plants and Brazil’s solar potential to implantation of floating plant system. A numerical analysis of power solar plants above reservoirs of the hydrelectric plant of Sobradinho and Tucuruí was realise, with this the energy generated would supply 91,21% of national power energy. The application of this results suggest the diversification of the Brazilian energy matrix. Keywords: Solar Energy. Floating Plants. Hydrelectric Plants. São Francisco River.

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Sakamoto, Hitoshi, Sho Igarashi, Mariko Uchida, Kazuma Niume et Masayuki Nagai. « Highly efficient all solid state dye-sensitized solar cells by the specific interaction of CuI with NCS groups II. Enhancement of the photovoltaic characteristics ». Organic Electronics 13, n^o 3 (mars 2012) : 514–18. http://dx.doi.org/10.1016/j.orgel.2011.11.017.

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Benavente-Araoz, Fabian, Jing Ying Ko, Anders Lundblad, Henrik Ekström et Göran Lindbergh. « An Aging Study of NCA/Si-Graphite Lithium-Ion Cells for Off-Grid Photovoltaic Systems in Bolivia ». Journal of The Electrochemical Society 168, n^o 10 (1 octobre 2021) : 100541. http://dx.doi.org/10.1149/1945-7111/ac315d.

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Chen, Guici, Tingting Zhang, Wenyu Qu et Wenbo Wang. « Photovoltaic Power Prediction Based on VMD-BRNN-TSP ». Mathematics 11, n^o 4 (17 février 2023) : 1033. http://dx.doi.org/10.3390/math11041033.

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Overfitting often occurs in neural network training, and neural networks with higher generalization ability are less prone to this phenomenon. Aiming at the problem that the generalization ability of photovoltaic (PV) power prediction model is insufficient, a PV power time-sharing prediction (TSP) model combining variational mode decomposition (VMD) and Bayesian regularization neural network (BRNN) is proposed. Firstly, the meteorological sequences related to the output power are selected by mutual information (MI) analysis. Secondly, VMD processing is performed on the filtered sequences, which is aimed at reducing the non-stationarity of the data; then, normalized cross-correlation (NCC) and signal-to-noise ratio (SNR) between the components obtained by signal decomposition and the original data are calculated, after which the key influencing factors are screened out to eliminate the correlation and redundancy of the data. Finally, the filtered meteorological sequences are divided into two datasets based on whether the irradiance of the day is zero or not. Meanwhile, the predictions are performed using BRNN for each of the two datasets. Then, the results are reordered in chronological order, and the prediction of PV power is realized conclusively. It was experimentally verified that the mean absolute value error (MAE) of the method proposed in this paper is 0.1281, which is reduced by 40.28% compared with the back propagation neural network (BPNN) model on the same dataset, the mean squared error (MSE) is 0.0962, and the coefficient of determination (R2) is 0.9907. Other error indicators also confirm that VMD is of much significance and TSP is contributive.

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