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Carbon Allotropes: Metal-Complex Chemistry, Properties and Applications || Classic Carbon Nanostructures
摘要： The era of carbon-based nanotechnology, as it is well-known, started from 1985 when the fullerene C60 was discovered. The rediscovery of carbon nanotubes and unexpected discovery of graphene gave a powerful impulse to the further development of carbon nanostructures. At present, these nanocarbons, as well as nanodiamonds or nanofibers, can already be considered as 'conventional' carbon nanostructures.
关键词： nanofibers,nanodiamonds,carbon nanotubes,graphene,carbon nanostructures,fullerenes
更新于2025-09-23 15:23:52
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Atomistic modeling of the infrared response of fullerenes under hydrostatic pressure
摘要： The anharmonic infrared spectrum of individual C60 and C70 fullerenes under hydrostatic pressure was theoretically computed by means of atomistic simulations. Using a tight-binding model for the fullerenes and a simple particle-based pressure-transmitting fluid, the structural and vibrational properties were determined at room temperature and up to 20 GPa. All properties generally exhibit relative variations that are linear with increasing pressure, but whose magnitude can be comparable to pure thermal effects. The bond length contraction usually agrees with existing results, and for C70 our approach manages to reproduce the occasionally negative pressure coefficient found for some low-frequency modes in experiments.
关键词： fullerenes,pressure effects,infrared spectroscopy
更新于2025-09-23 15:21:21
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Fullerenea??Based Interlayers for Breaking Energy Barriers in Organic Solar Cells
摘要： Organic solar cells (OSCs) are lightweight, flexible, and have easy solution processability, thus making them advantageous for large-area device fabrication. The interlayer materials between the electrodes and organic active layer are vital elements for device fabrication. Recently, solution-processable fullerene derivatives have been studied intensively as efficient electrode interlayer materials for solar cell applications. In this Minireview, we summarize recent advances using fullerene derivatives as interlayers in OSCs. The examples include fullerene interlayers from small molecules to polymers, and to organic composites or organic/inorganic hybrid materials. We focus on the comprehensive efforts in developing fullerene-based interlayers and present the understanding of multiple functionalities of these materials as cathode interlayers in bulk hetero-junction (BHJ) OSCs. Our motivation is to describe our current understanding, recent progress, and outstanding issues of fullerene interlayers in OSCs, and propose future potential directions and opportunities.
关键词： fullerenes,interlayers,organic solar cells,surface modifications,interface engineering
更新于2025-09-23 15:19:57
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a??Double-Acceptor-Typea?? Random Conjugated Terpolymer Donors for Additive-Free Non-Fullerene Organic Solar Cells
摘要： Random conjugated terpolymers (RCTs) not only promote great comprehension and realization for state-of-the-art high effective non-fullerene polymer solar cells (OSCs) but also offer a simple and practical synthetic strategy. However, the photovoltaic properties of RCTs yet lagged behind that of the donor-acceptor alternating copolymer, especially in the additive-free devices. Hence, we developed two feasible “double acceptor type” random conjugated terpolymers, PBDB-TAZ20 and PBDB-TAZ40. The additive-free OSCs based on PBDB-TAZ20:ITIC and PBDB-TAZ40:ITIC exhibit decent efficiencies of 12.34% and 11.27%, respectively, which both surpass the PBDB-T:ITIC-based device. For the RCTs, the reasonably weakened crystallinity and reduced phase separation degree are demonstrated to help improve charge transport, reduce bimolecular recombination and thus enhance the photovoltaic performance of the additive-free OSCs. The results imply that adding a third moiety into the D-A polymer donors provides a simple but efficient synthetic approach for high-performance OSCs.
关键词： polymer solar cells,crystallinity,non-fullerenes,morphology,random terpolymers
更新于2025-09-23 15:19:57
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Naphthalene and perylene diimides – better alternatives to fullerenes for organic electronics?
摘要： The LUMO levels of rylene diimides are highly comparable to those of fullerenes but this class of molecules offers tunability of both HOMO and LUMO levels and the related band gap by either simple substitution at the aromatic core or annulation to give expanded p-scaffolds. In this article we highlight the most outstanding achievements during the last decade in terms of charge carrier mobility for organic thin-film and single crystal field-effect transistors as well as photovoltaic performance for both small molecule and polymeric compounds.
关键词： fullerenes,perylene diimides,organic electronics,photovoltaic performance,naphthalene diimides,charge carrier mobility
更新于2025-09-19 17:15:36
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Graphenea??based polymer composites with ultraa??high ina??plane thermal conductivity: A comparison study between optothermal Raman spectroscopy and laser flash method
摘要： We developed a simple solution mixing and molding process for the incorporation of graphene nano-flakes (GNFs) in polymer films. Poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) and poly(ethylene-co-methacrylic acid) (PEMAA) were used for preparation of the samples. The orientation and stacking of GNFs were confirmed using a scanning electron microscope. The thermal conductivity values for these composites were obtained using (1) laser flash method (commercially available) and (2) an optothermal Raman (OTR) technique (homemade device). The former measures the thermal diffusivity (α) and one needs to measure the density (ρ) and the heat capacity (Cp) of the composites in order to measure the in-plane thermal conductivity (κ = α.ρ.Cp), while the latter measures the in-plane thermal conductivity directly from the relation between the excitation power and the position of the Raman resonance. The data obtained from Raman spectroscopy were analyzed, assuming heat propagation in three and two dimensions. The Raman results obtained based on the two-dimensional model were very close to the results obtained using the laser flash method with less than 10% difference. The OTR spectroscopy was found to be a promising technique for measuring the in-plane thermal conductivity of carbon-based polymer composites. PVDF-HFP and PEMAA composite films with very high in-plane thermal conductivity (25 W m?1 K?1) were obtained through the incorporation of GNFs (20 wt % concentration). Considering a very low thermal conductivity of these polymers (<0.2 W m?1 K?1), this corresponds to a large enhancement of roughly 12 400%. ? 2020 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020, 137, 48927.
关键词： nanotubes,conducting polymers,fullerenes,graphene,thermal properties,composites
更新于2025-09-19 17:13:59
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Pressure-Induced Dimerization of C60 at Room Temperature as Revealed by an In Situ Spectroscopy Study Using an Infrared Laser
摘要： Using in situ high-pressure Raman spectroscopy and X-ray di?raction, the polymerization and structure evaluation of C60 were studied up to 16 GPa at room temperature. The use of an 830 nm laser successfully eliminated the photo-polymerization of C60, which has interfered with the pressure e?ect in previous studies when a laser with a shorter wavelength was used as excitation. It was found that face-centered cubic (fcc) structured C60 transformed into simple cubic (sc) C60 due to the hint of free rotation for the C60 at 0.3 GPa. The pressure-induced dimerization of C60 was found to occur at about 3.2 GPa at room temperature. Our results suggest the bene?t and importance of the choice of the infrared laser as the excitation laser.
关键词： fullerenes,pressure-induced,infrared laser,polymerization,Raman
更新于2025-09-19 17:13:59
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Hybrid Fullerene-Based Electron Transport Layers Improving the Thermal Stability of Perovskite Solar Cells
摘要： The structure-dependent thermal stability of fullerene electron transport layers (ETLs) and its impact on device stability have been underrated for years. Based on co-crystallographic understanding, herein, we develop a thermal stable ETL comprising of a hybrid layer of [6, 6]-phenyl-C61-butyric acid methyl ester (PCBM) and [6, 6]-phenyl-C61-propylbenzene (PCPB). By tuning the weight ratios of PCBM and PCPB to influence the non-covalent intermolecular interactions and packing of fullerene derivatives, we obtained a champion device based on the 20PCPB (20 wt% addition of PCPB into the mixture of PCBM: PCPB) ETL and excellent thermal stability of 500 h under 85 °C thermal aging in N2 atmosphere in the dark. The present work exemplifies that co-crystallography can be a precise tool to probe interaction and aggregation of fullerene derivatives in ETLs, and mixed fullerene derivatives can be sought as promising ETLs to enhance the long-term stability of PSCs under high-temperature working environment.
关键词： fullerenes,electron transport layer,co-crystals,Perovskite solar cells,thermal stability
更新于2025-09-19 17:13:59
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Optical and electrical properties of fullerene C70 for solar cell applications
摘要： This research paper demonstrates the successful deposition of fullerene C70 for application as an acceptor material in Schottky barrier organic solar cell (OSC) device with structure fluorine-doped-tin-oxide/molybdenumtrioxide/fullerene/lithiumfluoride/aluminium (FTO/MoO3/C70/LiF/Al) using vapor thermal deposition technique. Morphology analysis using field emission scanning electron microscopy (FESEM) shows the mesoporous nature of highly cross-linked C70 molecules in deposited C70 thin film. But more uniform C70 film with less porosity has been deposited with high evaporation rate. We report the optical and electrical characterizations which reveal the thin film to be useful in photovoltaic applications. To study optical absorption spectra over visible energy range, prepared samples have been characterized by ultraviolet–visible (UV–vis) absorption spectroscopy. Optical dielectric parameters and dispersion properties of samples are studied. Constant Photocurrent Method (CPM) is employed to measure the mid gap absorption spectra of fabricated device. Defect density of states (DOS) distribution, Urbach energy and steepness parameter are also evaluated. Current-voltage characteristics of device in dark as well as under illumination surmise the behavior of device similar as Schottky barrier OSC.
关键词： Electrical properties,Optical properties,Fullerenes,Defects,Vapor deposition
更新于2025-09-19 17:13:59
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Fullerene for the Improvement of PbS QDs-Based Hybrid Solar Cells
摘要： In the present study, the hybrid photovoltaic devices based on PbS quantum dots (QDs) and poly(3-hexylthiophene-2,5diyl) have been fabricated. The effect of the insertion of [6,6]-phenyl C71 butyric acid methyl ester (PCBM) into the hybrid blend has been investigated and analyzed by using light and dark current density-voltage measurement, and impedance spectroscopy: capacitance-frequency and capacitance-voltage measurement. It is demonstrated that the introduction of PCBM into solar cells improves their efficiency with the optimal PCBM concentration of 3 wt %. It is shown that the main contribution in limitation of solar cells efficiency is brought by shallow traps induced by air exposure.
关键词： impedance spectroscopy,quantum dots,fullerenes,solar cells
更新于2025-09-16 10:30:52