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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
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Laser-induced graphene and carbon nanotubes as conductive carbon-based materials in environmental technology
摘要： Nanotechnology and nanomaterials have attracted interest due to their potential in mitigating contemporary environmental challenges, such as the stressors imposed by increased industrial and agricultural activities, and the deterioration of air, soil and water quality. In particular, advanced technologies that harness carbon-based nanomaterials are poised to emerge as tools that provide new solutions for the global water crises. These tools include, electrically conductive membrane processes, which uniquely combine a separation process with a functional surface. In this respect, laser-induced graphene (LIG) and carbon nanotubes (CNTs) are electrically conductive carbon nanomaterials that hold great utility in a multitude of environmental applications, including the development of fouling-resistant systems for desalination and water treatment, enhanced separation methods, and innovative pollutant sensing and electrocatalytic platforms. Consequently, this review article describes and compares some important recent advances in LIG- and CNT-based electroactive surfaces. The discussion of LIG as an emerging carbon material set in context with CNTs is intended to shed light on future directions and development possibilities to meet the growing global challenges in terms of water treatment applications of both materials as well as other electrically conductive carbon-based nanomaterials exhibiting exceptional performance and versatility.
关键词： environmental applications,nanomaterials,electrically conductive membrane processes,laser-induced graphene,Nanotechnology,water treatment,carbon nanotubes,carbon-based nanomaterials
更新于2025-09-16 10:30:52
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[IEEE 2019 IEEE 16th International Conference on Group IV Photonics (GFP) - Singapore, Singapore (2019.8.28-2019.8.30)] 2019 IEEE 16th International Conference on Group IV Photonics (GFP) - Towards Transparent on-Waveguide Electrical Circuits in SiN-Photonic Platform
摘要： We demonstrate transparent electrical conductors over SiN waveguides using metallic carbon nanotubes (CNTs). For an optimal coverage of 2 % over a SiN micro-ring resonator (MRR), negligible change in transmission is observed till a current density of 35 μA/μm.
关键词： SiN waveguides,micro-ring resonator,current density,metallic carbon nanotubes,transparent electrical conductors
更新于2025-09-16 10:30:52
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Electrode buffer layers via networks of polythiophene/polyaniline bottlebrushes and carbon nanotubes in organic solar cells
摘要： A new p-type electrode buffer layer (EBL) material was developed by the networks composed of multi-walled CNTs (MWCNTs) and poly(3-thiophene ethanol) (P3ThEt)-g-polyaniline (PANI) bottlebrush copolymers. The nanocomposites of CNT:P3ThEt-g-PANI were prepared in three different thicknesses (5, 15, and 25 nm) and employed as hole transport layer (HTL) in poly(3-hexylthiophene) (P3HT):phenyl-C71-butyric acid methyl ester (PC71BM) solar cells. A trade-off was detected between the sheet resistance and transmittance by elevating the HTL thickness for both pure CNT and CNT:P3ThEt-g-PANI nanocomposites. The CNT:P3ThEt-g-PANI thin films, in particular with an optimal thickness of 15 nm, were the turning points for equilibrating the film thickness, transmittance, surface roughness, and sheet resistance values. The smoothest thin films of CNT:P3ThEt-g-PANI with the thickness of 15 nm, the transmittance of 85–89%, and the sheet resistance of 5.6 × 104 Ω/sq reflected the best results of 12.85 mA/cm2, 60.7%, and 0.68 V. Hence, a maximum power conversion efficiency (PCE) of 5.30% was acquired among all solar cells fabricated in current work. After peaking at 15 nm, the second group of proper results was recognized in CNT:P3ThEt-g-PANI (25 nm)/P3HT:PC71BM photovoltaics (10.37 mA/cm2, 49.0%, and 0.62 V). The PCE of 3.15% for this system was even greater than the ideal performance (= 2.94%) detected in the pure CNT (15 nm)/P3HT:PC71BM solar cells.
关键词： Polyaniline,Electrode buffer layer,Carbon nanotubes,Organic solar cells,Polythiophene
更新于2025-09-16 10:30:52
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[IEEE 2019 16th International Multi-Conference on Systems, Signals & Devices (SSD) - Istanbul, Turkey (2019.3.21-2019.3.24)] 2019 16th International Multi-Conference on Systems, Signals & Devices (SSD) - Investigation of Laser Induced Graphene Electrodes Modified by MWNT/AuNPs for Detection of Nitrite
摘要： In this paper, a novel low cost electrode material for sensing is presented which demonstrates excellent electrochemical response to nitrite while being amenable to implementation in disposable point of care nitrite sensors. Laser induced grapheneous carbon (LIG) is based on a simple laser engraving method to fabricate electrodes by inducing conductive paths onto Kapton polymer substrate. The working electrode was modified by Gold Nanoparticles (AuNPs), multiwalled carbon nanotubes (MWCNT) and AuNPs/MWCNT. The modified electrodes were characterized by electron microscopy energy x-ray dispersive spectroscopy (SEM-EDX), cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). Surface morphology and electrochemical methods confirms confirm the successful implementation of LIG electrodes whose electrocatalytic performance is highly improved after modification. This suggests the synergetic effect between AuNPs and MWCNTs with the excellent conductivity and large specific surface area. By means of square wave voltammetry (SWV), the limit of detection of the proposed sensor is 6.75 μM, which is low enough for practical applications. In conclusion, AuNPs/MWCNT modified LIG electrodes demonstrated good electrochemical behavior and promising future use in disposable nitrite electrochemical sensors.
关键词： electrochemical sensing,nitrite detection,carbon nanotubes,gold nanoparticles,Laser induced graphene
更新于2025-09-16 10:30:52
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34.3: <i>Invited Paper:</i> Printing Pixel Circuits on Light Emitting Diode Array for AMLED Displays
摘要： An active matrix light emitting display module integrated with carbon nanotubes control circuits was fully printed. The high performance of super pure single-chirality carbon nanotube TFT provides super bright and low power consumption technologies for indoor and outdoor augmented reality that are highly desirable for civil and military display applications.
关键词： Aerosol Jet Printing,Active Matrix LED Display Module,Single Chirality Semiconducting Single-Walled Carbon Nanotubes,Thin Film Transistors,Light Emitting Diode Array
更新于2025-09-16 10:30:52
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Study of TiO2 nanotubes decorated with PbS nanoparticles elaborated by pulsed laser deposition: microstructural, optoelectronic and photoelectrochemical properties
摘要： Titanium dioxide nanotube arrays (TiO2 NTAs) have been synthesized using the electrochemical anodization procedure. Lead sulfide nanoparticles (PbS NPs) were deposited on TiO2 NTAs (PbS NPs/TiO2 NTAs) using the pulsed laser deposition (PLD) method. The prepared samples (PbS NPs/TiO2 NTAs) were characterized using scanning electron microscopy, transmission electron microscopy (TEM), X-ray diffraction (XRD), UV–Vis spectroscopy and photoluminescence. The size of the PbS NPs was controlled by varying the number of laser pulses (NLP) during the PLD process. TEM observations show that the PbS NPs are in the range of 10–20 nm, consistent with the results obtained from XRD. HRTEM and diffuse reflectivity show that, at NLP ≥ 2500, the growth of the PbS NPs occurs on a previously formed PbS layer. Transmission and absorption spectra show that the PbS-NPs have an indirect optical bandgap which is particle size independent. This optical bandgap corresponds to excitonic transitions, which are greatly affected by oxygen defects, off-stoichiometry and other surface state defects, particularly for smaller NPs (NLP < 2500). The absorption spectra of the TiO2 NTAs show that the PbS NPs extend the absorption range of the TiO2-NTAs from the ultraviolet to the visible region, indicating that the PbS NPs/TiO2 NTAs heterojunction facilitates the separation of the photogenerated charge carriers. Photoelectrochemical analyses show that a maximum photocurrent current density of ~1.05 mA/cm2 and a photoelectrochemical conversion efficiency of 2.5% are reached for NLP = 2500 under an illumination of 100 mW/cm2 in the UV–Vis range.
关键词： TiO2 nanotubes,Photoelectrochemical properties,PbS nanoparticles,PLD
更新于2025-09-16 10:30:52
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A Long π-Conjugated Poly-para-Phenylene-Based Polymeric Segment of Single-Walled Carbon Nanotubes
摘要： Conjugated polymers have attracted much attention for many years and have applications in various organic devices. Carbon nanotubes can be considered as all-carbon tube-shaped conjugated polymers containing only sp2-bonded atoms, which play an important role in nanotechnology and nanoelectronics. So far, no study has reported the realization of long π-conjugated polymers as diameter-specified carbon nanotube segments. Herein, we report the first synthesis of a π-conjugated polymeric segment (PS1) of armchair single-walled carbon nanotubes (SWCNTs). PS1 is achieved by a rationally designed synthesis of a bifunctionalized cyclo-para-phenylene monomer, followed by inserting these ring-shaped units into the conjugated poly-para-phenylene backbone. PS1 was fully characterized by gel permeation chromatography (GPC) combined with NMR, FTIR, and Raman spectra. Possessing unique structural and physical properties, this long π-extended polymer PS1 can provide new insight for the development of bottom-up syntheses of uniform carbon nanotube segments and potential applications in electron- and hole-transport devices.
关键词： electron-transport devices,bottom-up synthesis,poly-para-phenylene,carbon nanotubes,π-conjugated polymers,hole-transport devices
更新于2025-09-16 10:30:52
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Preparation of Hybrid Molybdenum Disulfide/Single Wall Carbon Nanotube–n-Type Silicon Solar Cells
摘要： Carbon nanotube/silicon (CNT/Si) heterojunction solar cells represent one new architecture for photovoltaic devices. The addition of MoS2 to the devices is shown to increase the e?ciency of the devices. Two structures are explored. In one case, the single wall carbon nanotubes (SWCNTs) and MoS2 ?akes are mixed to make a hybrid, which is then used to make a ?lm, while in the other case, a two layer system is used with the MoS2 deposited ?rst followed by the SWCNTs. In all cases, the solar cell e?ciency is improved largely due to signi?cant increases in the ?ll factor. The rise in ?ll factor is due to the semiconducting nature of the MoS2, which helps with the separation of charge carriers.
关键词： molybdenum disul?de (MoS2),single wall carbon nanotubes (SWCNTs),thin ?lm,solar cells
更新于2025-09-16 10:30:52