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Machine Learning for Tailoring Optoelectronic Properties of Single-Walled Carbon Nanotube Films
摘要： A machine learning technique, namely support vector regression, is implemented to enhance single-walled carbon nanotube (SWCNT) thin-film performance for transparent and conducting applications. We collected a comprehensive dataset describing the influence of synthesis parameters (temperature and CO2 concentration) on the equivalent sheet resistance (at 90% transmittance in the visible light range) for SWCNT films obtained by a semi-industrial aerosol (floating-catalyst) CVD with CO as a carbon source and ferrocene as a catalyst precursor. The predictive model trained on the dataset shows principal applicability of the method for refining synthesis conditions towards the advanced optoelectronic performance of multi-parameter processes such as nanotube growth. Further doping of the improved carbon nanotube films with HAuCl4 results in the equivalent sheet resistance of 39 Ω/□ – one of the lowest values achieved so far for SWCNT films.
关键词： transparent conductive films,support vector regression,single-walled carbon nanotubes,optoelectronic properties,machine learning
更新于2025-09-19 17:13:59
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Thin film chemiresistive gas sensor on single-walled carbon nanotubes-functionalized with polyethylenimine (PEI) for $${\hbox {NO}}_{2}$$NO2 gas sensing
摘要： Chemical detection of toxic gases, such as greenhouse gases is still very important as a research topic. To design gas sensor detectors based on single-walled carbon nanotubes (SWCNTs) with high sensitivity and selectivity for the toxic environment is a continuous process. The aim is to detect NO2 gas with better sensitivity. In the present work, the thin-film sensor is fabricated on SiO2 substrate and it is functionalized with polyethylenimine (PEI). It has been established that PEI functionalized SWCNTs (F-SWCNTs) show high sensitivity towards strong electron-withdrawing particles. It was found that at room temperature, SWCNTs-PEI functionalized gas sensor exhibited a higher sensitivity of 37.00% as compared with bare SWCNTs gas sensor. The gas sensor has shown the repeatable response for the entire concentration range studied. The sensing properties and the PEI functionalization duration effects on the behaviour of SWCNTs-based gas sensors were demonstrated.
关键词： NO2,Carbon nanotubes,sensor,polyethylenimine (PEI)
更新于2025-09-19 17:13:59
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Preparation and Characterization of UV-LED Curable Acrylic Films Containing Biochar and/or Multiwalled Carbon Nanotubes: Effect of the Filler Loading on the Rheological, Thermal and Optical Properties
摘要： UV-LED curable coatings represent an up-to-date attractive field due to the high curing efficiency even in the presence of high filler loadings, as well as to the absence of infrared wavelengths that may negatively impact on heat-sensitive substrates. The addition of carbonaceous materials, such as biochar (BC) and/or multiwalled carbon nanotubes (MWCNTs) could positively improve both the rheological and thermal properties. In this study we report on the synthesis and characterization of carbon-reinforced films containing nanometric (MWCNTs) and micrometric (BC) carbon-based materials. We analyze the rheological properties of the UV-LED curable dispersions, as well as the thermal and optical properties of the resulting films, establishing some correlations between filler dispersion/loading with the main observed properties.
关键词： composites,epoxy-acrylate resin,biochar,multiwalled carbon nanotubes,UV-LED curing
更新于2025-09-19 17:13:59
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Polarization-dependent pulse dynamics of mode-locked fiber laser with near-zero net dispersion
摘要： We demonstrate novel polarization-dependent pulse dynamics in a fiber laser cavity mode-locked by single-wall carbon nanotubes. By managing the net dispersion and polarization state, we obtain two noise-like pulsing procedures with distinctive polarization characteristics. Ultrafast polarization measurements reveal double pulses are produced by the combined effects of double-scroll chaotic polarization attractors and the polarization mode dispersion of single-mode fiber. The corresponding single-shot spectra provide evidence of coherent energy coupling between pulses during the switching process, due to the polarization hole burning of the active medium. The relative results provide new information for the polarization control of ultrafast lasers.
关键词： polarization-dependent pulse dynamics,single-wall carbon nanotubes,polarization hole burning,near-zero net dispersion,mode-locked fiber laser
更新于2025-09-19 17:13:59
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Cobalt ferrite decorated multiwalled carbon nanotubes as the electrode for efficient field electron emission
摘要： In the present study, Cobalt Ferrite (CF) nanoparticles with different weight concentrations were successfully decorated on Multi-Walled Carbon nanotubes (MWCNT) using a simple glycol assisted chemical route. The physicochemical and electronic properties of CF decorated MWCNTs (MWCNT-CF) were accomplished with the help of different techniques such as X-ray Diffraction (XRD), Raman Spectroscopy, Transmission Electron Microscopy (TEM), X-ray Photo-electron Spectroscopy (XPS) and Fourier Transform Infrared Spectroscopy (FTIR). Further, the effect of CF concentration on Field Emission (FE) characteristics of MWCNT-CF is investigated. The FE studies revealed that, CF decorated MWCNT emitter (MWCNT-CF; 1:1) exhibits lower turn on (0.52 V/μm, at 10 μA/cm2) and threshold fields (0.62 V/μm, at 100 μA/cm2) in contrast to pristine CF, MWCNT, and MWCNT-CF (1:0.5 and 1:2). Interestingly, from the MWCNT-CF (1:1) emitter, very high emission current density ~ 10408 μA/cm2 has been extracted at a relatively lower applied field of 1.18 V/μm. The enhancement in FE characteristics of MWCNT-CF emitters is attributed to lowering of work function measured from the UPS analysis and increased number of emitting sites. The results imply that very high current density field emitters can be fabricated using a simple strategy based on the decoration of MWCNT’s with CF nanoparticles.
关键词： Reflux,Cobalt Ferrite,Multiwalled Carbon Nanotubes,Field Emission,Nanoparticles
更新于2025-09-19 17:13:59
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Enhancing the performance of photovoltaic operating under harsh conditions using carbon-nanotube thermoelectric harvesters
摘要： This paper proposes a novel configuration for enhancing the efficiency of photovoltaics (PV) operating in high-temperature environment using a nano-thermoelectric carbon nanotube-based harvester attached to the backside of the solar cell (SC). The attached harvester will not only extract heat energy from the cell but will also convert this wasted heat energy into electrical energy. The proposed configuration has been fabricated and tested experimentally, where I–V measurements have been conducted. An overall enhancement in SC efficiency of 50%, with respect to reference cell, has been achieved using the proposed harvester. In addition, the harvester itself provided a power in the range of hundreds of microwatts that can be utilized in various low-power applications.
关键词： High-temperature environment,Thermoelectric harvester,Solar cell efficiency,Photovoltaics,Carbon nanotubes
更新于2025-09-19 17:13:59
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Photoa??thermal conversion and heat storage characteristics of multia??walled carbon nanotubes dispersed magnetic phase change microcapsules slurry
摘要： The development of high-efficient working fluids with excellent photo-thermal conversion and heat storage properties is an important factor to solar thermal utilization. In this work, magnetic phase change microcapsules (MPCMs) were prepared via in situ polymerization, where melamine-formaldehyde resin (MF) and oleic acid-coated magnetic nanoparticles (OA-MNs) were used as the shell and core, respectively. The microstructure, magnetic and thermal properties of MPCMs were investigated, and the photo-thermal conversion and heat storage properties of slurries prepared by dispersing MPCMs into multi-walled carbon nanotubes (MWCNTs) nanofluids were explored. The encapsulation efficiency of MPCMs with super-paramagnetic nature achieved 63.51%, while the thermal conductivity of MPCMs was slightly increased with regard to phase change microcapsules (PCMs) and the thermal stability of octadecane was enhanced after being encapsulated. Moreover, the slurry with 0.01 wt% MWCNTs and 15 wt% MPCMs had the optimal photo-thermal conversion properties and thermal storage capacity. Beyond that, the recycled MPCMs represented excellent recyclability. Our research demonstrated that the MWCNTs-dispersed MPCMs slurry is one of ideal working fluids with excellent photo-thermal conversion and heat storage characteristics for direct absorption solar collector.
关键词： carbon nanotubes,direct absorption solar collector,photo-thermal conversion,heat storage,microcapsules
更新于2025-09-19 17:13:59
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Covalently bonded polyaniline-reduced graphene oxide/single-walled carbon nanotubes nanocomposites: influence of various dimensional carbon nanostructures on the electrochromic behavior of PANI
摘要： In this paper, water-dispersible and covalently bonded polyaniline-carbon nanostructures, including polyaniline-reduced graphene oxide (PANI-rGO), polyaniline-single-walled carbon nanotubes (PANI-SWCNTs), and polyaniline-reduced graphene oxide/single-walled carbon nanotube (PANI-rGO/SWCNTs) nanocomposites, were synthesized by grafting PANI onto p-phenylenediamine (PPD)-functionalized graphene oxide (GO) or single-walled carbon nanotubes (SWCNTs) using polystyrene sulfonate (PSS) as a macromolecular dopant agent. The structures and morphologies of the PANI, PANI-rGO, PANI-SWCNTs, and PANI-rGO/SWCNTs nanocomposites were characterized by Fourier transform infrared spectroscopy and scanning electron microscopy. The cyclic voltammetry and UV–vis spectra were performed on an electrochemical workstation and a UV–vis spectrometer, respectively. The results show that the electrochromic and electrochemical properties of nanocomposites can bene?t from the high conductivity of SWCNTs and the abundant active sites of rGO. When SWCNTs and rGO work together, their respective shortcomings are overcome, allowing the nanocomposite to exhibit the best electrochemical and electrochromic properties. The optical contrast increased from 0.38 for PANI to 0.52 for PANI-rGO/SWCNTs. The coloring and bleaching times decreased from 2.59 s and 2.39 s, respectively, for PANI to 1.33 and 0.78 s, respectively, for PANI-rGO/SWCNTs. The charge transfer resistance (Rct) decreased from 135 Ω for PANI to 30 Ω for PANI-rGO/SWCNTs. The synergistic effect of PANI, rGO, and SWCNTs can signi?cantly improve the electrochromic ability of PANI.
关键词： single-walled carbon nanotubes,reduced graphene oxide,electrochromic,polyaniline,nanocomposites
更新于2025-09-19 17:13:59
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Hidden Fine Structure of Quantum Defects Revealed by Single Carbon Nanotube Magneto-Photoluminescence
摘要： Organic color-center quantum defects in semiconducting carbon nanotube hosts are rapidly emerging as promising candidates for solid-state quantum information technologies. However, it is unclear whether these defect color-centers could support the spin or pseudo-spin dependent excitonic fine structure required for spin manipulation and readout. Here we conducted magneto-photoluminescence spectroscopy on individual organic color-centers and observed the emergence of fine structure states under an 8.5 T magnetic field applied parallel to the nanotube axis. One to five fine structure states emerge depending on the chirality of the nanotube host, nature of chemical functional group, and chemical binding configuration, presenting an exciting opportunity toward developing chemical control of magnetic brightening. We attribute these hidden excitonic fine structure states to field-induced mixing of singlet excitons trapped at sp3 defects and delocalized band-edge triplet excitons. These findings provide opportunities for using organic color-centers for spintronics, spin based quantum computing, and quantum sensing.
关键词： triplet,magnetic field,sp3 defect,photoluminescence,hybridization,carbon nanotubes
更新于2025-09-19 17:13:59
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Role of Carbon Nanotubes to Enhance the Long-Term Stability of Dye-Sensitized Solar Cells
摘要： Improving the long-term stability of Dye-sensitized solar cells (DSSCs) is a critical challenge which affects both their technical viability and future large-scale commercialization. Here, we investigate the role of multi-wall carbon nanotubes (MWCNTs) in improving the long-term stability of DSSCs by comparing the performance of two series of devices made of (i) bare nanocrystalline TiO2 and (ii) MWCNTs-TiO2 composite anode, exposed to continuous simulated sunlight, indoor and ultraviolet (UV) light irradiation. The DSSCs based on the composite anode showed approximately three times longer stability compared to the standard device. To understand the degradation mechanisms that underpin these changes in device performance, both devices were characterized using various techniques. The results indicate that the MWCNTs can act as a conductive support, reinforcing the TiO2 nanoparticles matrix and offering a directional path to the photo-injected electrons, which enhances electron lifetime and reduces the carrier recombination rate. UV stability measurements demonstrated that MWCNTs can partially absorb and act as a blocking agent for UV light, thereby preventing degradation. The Raman spectra showed that dye desorption was decreased by the addition of MWCNTs. Our results provide a fundamental understanding of photoanode degradation mechanisms under illumination and offer a simple, low-cost and large-area scalable approach to fabricate long-term stable solar energy conversion devices.
关键词： Multi-walled carbon nanotubes,Long-term stability,Dye-sensitized solar cells,hybrid composite,degradation mechanism
更新于2025-09-19 17:13:59