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We report weak ferromagnetism in fullerene thin films at the temperature of 2K-300K by 600 keV carbon ion irradiation. The fullerene thin films were irradiated with 600 keV carbon ions. The thin films of fullerene exhibit a significant and stable weak ferromagnetic ordering at room temperature after irradiation with variable ion fluence. Fullerene has exhibited a maximum magnetic ordering with carbon ion beam irradiation at the ion fluence of 0.03 pC/µm2 in the present experiment. The observed ferromagnetic ordering diminishes upon irradiation with higher fluences due to a higher degree of damage, which is confirmed by the Glancing angle x-ray diffraction and Raman analysis results. The saturation magnetic moments rapidly reduce, as we increase the fluence. Computational simulations have been performed to determine the approximate distance between defects and their relation with observed ferromagnetism, utilizing simulation studies from Stopping Range of Ions in Matter (SRIM) codes for the present experimental conditions. The correlation between theoretical as well as experimental studies reveals, that the fullerene thin films, get amorphized with the fluence of 0.03 pC/µm2 and beyond for 600 keV carbon ion irradiation. We have applied moderate ion flux to avoid the possibility of annealing during the carbon ion irradiation. We report our findings with systematic analysis in the present manuscript. [ABSTRACT FROM AUTHOR]

C60 and C60-ZnO thin films were synthesized by spray pyrolysis method, and structural, chemical, optical and self-cleaning characterizations of this nanocomposite were performed before and after plasma treatment. The C60 thin film has a very wide peak in the range of 2θ = 15–35°, which indicates the amorphous structure of this film. After plasma treatment, fullerene peaks appear at angles of 2θ = 13.94, 17°. Fullerene peaks in the C60-ZnO and C60 thin films are similar and are seen exactly at the same angles. The location of zinc oxide peaks did not change before and after plasma treatment. The presence of fullerene peaks in the studied thin films after plasma treatment indicates that the crystallographic quality of C60 and ZnO-C60 thin films has improved. FESEM image of fullerene thin films before and after plasma treatment shows that fullerene nanoparticles are almost spherical. After plasma treatment, the particle size is reduced, and all particles are below 50 nm with spherical shape. FESEM images of C60-ZnO thin film after plasma treatment show both fullerene and zinc oxide particles become smaller and the particles have a uniform distribution. The results of FTIR chemical analysis in thin film samples show the chemical bonds of the nanocomposite before and after plasma treatment. In AFM images, the surface of the C60 thin film is smooth and uniform before plasma compared to after plasma processing. Also, in C60-ZnO composite, the grain size after plasma treatment is much larger than before plasma treatment. The contact angle of the thin films indicates that the composite samples become hydrophobic after plasma processing. [ABSTRACT FROM AUTHOR]

Cellulose nanocrystals (CNCs) are renewable, sustainable and biocompatible nanomaterials, which have gained great attention in last years for their potentialities in several fields of application. With their polyelectrolyte behaviour, sulphated CNCs are suitable to produce multilayered architectures with cationic molecules. In this work, we have investigated the ability of anionic CNCs to assist the two-dimensional organization of two cationic fulleropyrrolidines at the air/water interface, leading to hybrid Langmuir-Schäfer films with improved (photo)electrical properties. We demonstrated that CNCs interact with the fulleropyrrolidines at the air/water interface, favouring the assembly of organized hybrid C 60 /CNC films. The transfer efficiency of Langmuir layers and the morphological regularity of supported films proved to be influenced by the extent of positive charge on the fullerene counterpart. Interestingly, the electrochemical characterization of hybrid films revealed that sulphated nanocellulose strongly improves the electrical properties of organized fullerene layers, by increasing their conductivity and favouring the hydrogen evolution reaction. Moreover, the well-established C 60 photoactivity proved to be enhanced by CNCs, as demonstrated by the higher intensity of photocurrents. This outstanding nanocellulose impact on fullerene film electrical properties paves the way to the development of more performing C 60 -based electrochemical devices, able to better exploit the unique properties of carbon nanostructures. Image 1 [ABSTRACT FROM AUTHOR]

We have probed the structural and magnetic properties of a ferromagnetic/organic interface constituted by a polycrystalline Co layer deposited on a fullerene thin film through resonant soft X-ray reflectivity measurements. The fitting analysis of the reflectivity indicates the formation of a sharp interface with limited intermixing and a null remanent magnetization in a ~1 nm thick region of the Co film at the interface with C60. This information contributes to elucidate the role of organic–inorganic interfaces in the charge and spin transport inside organic spintronic devices. [ABSTRACT FROM AUTHOR]

Bi-functional nanocomposite thin films of fullerene C60 and C70 containing Au NPs were synthesized using thermal co-evaporation method. Different atomic concentrations of Au metal varying from 5 to 35 at.% was chosen to get the Au NPs with different sizes in fullerene matrix. The thickness of films and metal concentration is confirmed by Rutherford backscattering spectroscopy (RBS). UV-visible spectrum shows the excitation of SPR band in all samples except for the lowest metal concentration which is ~ 5 at.% and SPR is red shifted with increasing concentration of Au. The shift in SPR position with increasing metal concentration for both Au-C60 and Au-C70 is nearly linear. X-ray diffraction spectroscopy indicates the formation of bigger size particles with increasing metal concentration in both the cases of Au-C60 and Au-C70, which is further confirmed by transmission electron microscopy results. Au-C60 and Au-C70 (could) be interesting nanocomposites for surface-enhanced Raman scattering studies. [ABSTRACT FROM AUTHOR]

Hydrogenated fullerenelike carbon (H-FLC) films, with high hardness of 41.7 ± 1.4 GPa and elastic recovery of ∼75.1%, have been uniformly deposited at low temperature by pulse direct current plasma enhanced chemical vapor deposition (pulse DC PECVD). The superior mechanical properties of the H-FLC films are attributed to the unique curvature and interconnection of graphitic basal planes. We propose the fullerenelike structures are formed in the far nonequilibrium pulse plasma environment and stabilized in the sequential fast quenching process. It is expected that the facile deposition of H-FLC films will promote the large-scale low-temperature preparation of engineering protective films for industrial applications. [ABSTRACT FROM AUTHOR]

Three primary colors, red, green, and blue have been obtained from a single-emission layer organic light-emitting diode (OLED) through optical design using a half-wavelength all-metal-cavity device. Fullerene is used as an electron transport layer to further enhance the electrical performance of the cavity device and the optical tuning of the cavity OLED. This fullerene layer results in a ∼2 V driving voltage reduction and a ∼20% increase in power efficiency, as compared with traditional cavity OLED with Alq as the electron transport layer. The emissive spectra for the cavity OLEDs are well predicted by the Fabry–Perot cavity theory. The spectral narrowing and intensity enhancement at the resonance wavelength have been observed and are explained by the redistribution of optical-mode density inside the microcavity. Schemes to tune the emissive color by varying the cavity length through variations of indium tin oxide thickness, hole transport layer thickness, and electron transport thickness, individually or collectively, have been proposed and demonstrated. [ABSTRACT FROM AUTHOR]

ABSTRACT: Optical properties of polymer/fullerene blend films upon thermal annealing are investigated by spectroscopic ellipsometry and described consistently within an optical model of the blend film. The optical model developed in this work treats both components, polymer and fullerene, as mixtures of reference materials, that is, their optically ordered and disordered phase. Then, the polymer/fullerene blend layer is also described as a mixture of these two components. In this manner, we extend an existing optical model, which accounts for the optical order within the polymer phases, on cases where the optically ordered PCBM phase occurs, too. Determination of the dielectric functions of all four reference materials allows for a unique quantitative characterization of a polymer/fullerene blend film by assigning to it thickness and the polymer to fullerene volume fraction of its layers as well as corresponding volume fractions of theirs optically ordered and disordered polymer and fullerene phases. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2018, 56, 1094–1100 [ABSTRACT FROM AUTHOR]

We report a 220 keV Ag ion beam irradiation-induced modifications of thin films of fullerene C 60 containing gold (Au) nanoparticles. Nanocomposite thin films of Au-C 60 were synthesized using a thermal co-deposition technique on a glass substrate. The as-deposited (pristine) thin films were irradiated by 220 keV Ag ion beam at different fluences ranging from 1 × 1013 ions/cm2 to 3 × 1016 ions/cm2 utilizing a low energy ion accelerator. The optical properties of pristine and irradiated thin films of Au-C 60 were investigated using UV–visible spectroscopy. A redshift in the Surface Plasmon Resonance (SPR) wavelength from ~ 598–775 nm was obtained with increasing fluence up to 1 × 1014 ions/cm2, which indicated the growth of Au nanoparticles in the fullerene matrix due to ion irradiation. It was further confirmed by High-Resolution Transmission Electron Microscopy (HRTEM). With further increase in fluence, a blue shift from ~ 775–570 nm was obtained at a fluence of 1 × 1016 ions/cm2. The transformation of fullerene C 60 into amorphous carbon (a:C) with increasing fluence of Ag ion beam was the main cause of this blue shift which was further confirmed by Raman spectroscopy. An increase in surface grain size with ion fluence was observed by Atomic Force Microscopy (AFM) and Field Emission Scanning Electron Microscope (FESEM). The X-ray Photoelectron Spectroscopy (XPS) measurements were used for the chemical state analysis of the nanocomposite thin films before and after irradiation. The current-voltage measurements confirm the increase in the conductivity of the nanocomposite films with the fluence due to its transformation in carbon at higher fluences. The control on the size of Au nanoparticles and tuning of SPR wavelength by low energy ion irradiation may enhance the applicability of Au-C 60 nanocomposite in organic solar cell. • Synthesis of Au-C60 nanocomposites utilizing the co-evaporation technique. • Irradiation with 220 keV silver ion beam • Red and blue shift in the Surface plasmon resonance wavelength • Growth of gold nanoparticles with increasing dose. [ABSTRACT FROM AUTHOR]

Magnetic properties of carbon vary according to its allotropic modifications. Although carbon atom is known as a diamagnetic, some distinctive features point out that its magnetic properties are not that simple. Fullerene C60, a carbon atoms molecule, is proven to have very different magnetizations than other forms of carbon compounds. Rhombohedral fullerene is shown to have ferromagnetic properties, and thus investigations of fullerene as a magnetic material are necessary. Fullerene C60in the form of thin film is also shown to have distinctive magnetic properties. In this paper, remanent magnetization of fullerene thin films, thicknesses of 100 and 250 nm were investigated when films are in the dark and exposed to polarized light. Research showed how light is influencing the material and its magnetization. [ABSTRACT FROM AUTHOR]

The molecular orientation of selected low band gap polymers for organic photovoltaics (Si-PCPDTBT, PCPDTBT, and PCPDTBBT) and the influence of PCBM on the orientation is studied using Near-Edge X-Ray Absorption Fine Structure spectroscopy (NEXAFS). The results are compared to the state of the art material P3HT. A clear angular dependence in the S-K NEXAFS spectra points to a preferred orientation of the π-conjugated system and thus to a high degree of ordering for most materials. Generally, the degree of ordering decreases after blending the polymer with the fullerene PCBM. In the case of P3HT and PCPDTBT, the degree of ordering could be improved considerably due to the annealing of the film. The annealing temperatures depend however on the considered polymer. [ABSTRACT FROM AUTHOR]

Highlights: [•] Fullerene films are excited with infrared lasers and ions (positive and negative) are detected with time-of-flight mass spectrometry. [•] The mechanism of infrared desorption and ionization is investigated with different samples and IR wavelengths. [•] Tunable IR studies provide desorbed ion infrared spectra of C60, revealing new vibrational combination bands. [Copyright &y& Elsevier]

Highlights: [•] The Fe+ beam was irradiated to the C60 thin films. [•] The Fe+-irradiated C60 thin films were analyzed by LDI-TOF-MS and by HPLC. [•] The peak with mass/charge of 776 was observed in the Fe+-irradiated C60 thin film. [•] We could synthesize the Fe–C60 complex as a new material. [Copyright &y& Elsevier]

Abstract: The morphology of composite films consisting of conjugated polymers and C60 prepared by electrophoretic deposition (EPD) has been studied. While C60 exists as nanocrystals uniformly embedded in the composite films based on poly[2-methoxy-5-(2′-ethylhexyloxy)-1,4-phenylene vinylene], a spontaneous stratification of the composite films into polymer-C60-mixture and C60-microcrystal layers is observed in the films based on a polyfluorene derivative, poly[(9,9-dioctyl-2,7-divinylenefluorenylene)-alt-{2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylene}]. The results suggest that EPD can be a useful tool for controlling the morphology of bulk heterojunction systems for organic photocells. [Copyright &y& Elsevier]

Abstract: A Monte Carlo molecular simulation study is presented on the adsorption and growth of C60 films on the surface of the (110) face of rutile. Simulations are performed for a temperature of 600K using atomistic models both for the fullerene molecules and the TiO2 surface. It is found in this work that C60 is adsorbed preferably in an ordered arrangement along the surface depressions over the exposed undercoordinated Ti cations. At low densities adsorption occurs preferably at alternate rows, with locations in consecutive rows being occupied appreciably only at higher C60 densities. At low densities, the fullerene molecules tend to aggregate into islands in the surface plane. Additional layers of C60 form only as the density increases, and do so before a monolayer is completed in all consecutive rows. Full monolayer capacity obtained at the highest densities is about 0.9C60 molecules per nm2, but this is only achieved by completing the packing of molecules in interstices at a slightly upper level. The fraction of the molecules that lie closest to the surface only amounts to 0.6molecules per nm2. [Copyright &y& Elsevier]

Fullerene films grown by various methods are studied using mass spectrometry. The mass spectra of the films formed onto an aluminum foil using thermal deposition (TD) or supersonic molecular beam (SMB) exhibit a small change in the mass peak distribution in the C120 dimer range as compared to the initial fullerene powder during desorption by laser radiation irrespective of the radiation wavelength (λ = 259, 518 nm). Under the action of laser radiation with wavelength λ = 259 nm, fullerene films grown on a silicon substrate with an SMB also exhibit a small change in the mass peak distribution in the C120 dimer range. At λ = 518 nm, the mass peak distribution in the dimer range shifts significantly toward small masses, so that the intensity maximum corresponds to M ≅ C102. This fact is assumed to be related to the polymerization of an SMB fullerene film caused by heating due to the absorption of laser radiation with a wavelength λ = 518 nm. [ABSTRACT FROM AUTHOR]

In this work, the results of structural modification of fullerene thin films bombarded by multiple charged nitrogen ions have been reported. The properties of as-deposited and irraditated fullerene thin films have been investigated by Raman and FTIR spectroscopy and AFM analysis. After irradiation by multiple charged nitrogen ions (N2+, N5+) new bondings in fullerene films have been formed and the amorphicity has been enhanced at higher doses. Raman and FTIR spectra showed structural changes of deposited films depending on the energy and implantation dose. AFM analysis showed that the ion beam had destroyed the surface ordering. At lower doses the surface order has been characterized by carbon clusters of 500 nm. At higher doses significantly smaller clusters have been formed (200 nm). [ABSTRACT FROM AUTHOR]

Abstract: A detailed UV–Vis spectrophotometric, thermodynamic and NMR studies have been carried out to look insight into the nature of molecular interactions of the electron donor–acceptor complexes of [60]fullerene with three different polycyclic aromatic hydrocarbon (PAH) molecules in CCl4 medium. Well defined charge transfer (CT) absorption bands have been located in the visible region. We extract degrees of charge transfer, oscillator and transition dipole strengths by analyzing the transition energy of the CT band as a function of vertical ionization potentials of the donors studied. The influences of the PAH on the absorption spectrum of [60]fullerene are studied. The experimental results have been explained using a theoretical model that takes into account the interaction between electronic subsystems of PAH with [60]fullerene. Formation constants (K) of the [60]fullerene/PAH complexes are determined spectrophotometrically (utilizing Benesi–Hildebrand equation) at four different temperatures and by 1H NMR spectroscopic technique. Trend in the formation constant values for the [60]fullerene/PAH complexes are discussed in terms of enthalpies and entropies of formation. Free energies of formation values for the [60]fullerene/PAH systems as well as ab initio calculation suggest that nature of substitution and steric effect in the PAH systems play vital role in formation of EDA complexes with [60]fullerene. [Copyright &y& Elsevier]

The nonlinear refraction in thin films of fullerene C60 (100 nm) is studied by the Z- and RZ-scan methods using the second harmonic of a picosecond Nd:YAG laser (λ = 532 nm, τ = 55 ps). The combined effect of n2 (self-focusing of laser radiation) and n4 (self-defocusing) is analyzed. Mechanisms responsible for the nonlinear refraction in films are discussed. © 2005 Pleiades Publishing, Inc. [ABSTRACT FROM AUTHOR]

The author has prepared high-quality fullerene/PMMA films in which fullerenes are uniformly embedded. The films are optically transparent. The products were characterized spectroscopically using UV/Vis and FTIR. The optical band gap of fullerene/PMMA films were reduced by increasing the fullerene concentration. The refractive index spectrum and absorption index spectrum of fullerene/PMMA films were determined in the wavelength range (200-2400nm) from the combination of reflectance R and transmission T at normal incidence. [ABSTRACT FROM AUTHOR]

Abstract: Thin films and bulk samples of endohedral fullerenes Li@C60 are studied using current–voltage (I–V) measurements and electron paramagnetic resonance (EPR). Electrical measurements show a linear behaviour for the I–V curves and give an average resistivity of ca. 1.5kΩcm for thin Li@C60 films deposited in vacuum, four orders of magnitude lower than C60 samples. A drastic effect on the conductance, lowering it to the values typical for C60, is observed when the Li@C60 samples are exposed to ambient atmosphere. No additional paramagnetic centres (PCs) are found for the Li@C60 compared to C60 that can be related to the formation of dimers or trimers of the endohedral fullerene molecules. However, the presence of the Li atoms in the fullerene cages contributes to a change of the spin–spin and spin–lattice relaxation times. The spin–lattice relaxation time becomes four orders of magnitude longer compared to the spin–spin relaxation time. [Copyright &y& Elsevier]

• GISAXS was used to characterize PRI effect for LIPSS in fullerene thin films. • Simulation of GISAXS patterns provides relevant structural information of PRI effect. • LIPSS in PC 71 BM films can be described as paracrystalline one-dimensional structures. • GISAXS can be used for future real-time characterization of PRI in nanotechnology. In this article we explore the potential of synchrotron Grazing Incidence Small Angle X-ray Scattering (GISAXS) to evaluate the extension of a Photoinduced Resist-free Imprinting (PRI) effect for grating-like Laser Induced Periodic Surface Structures (LIPSS) on spin-coated thin films of the fullerene derivative [6,6]-phenyl C 71 -butyric acid methyl ester (PC 71 BM). Valuable information about the nature of both the original fullerene LIPSS and of the remaining resist-free nanostructure in terms of geometry, size distribution, lattice periodicity and degree of order can be achieved by simulations of the GISAXS patterns. One of the most interesting features provided by the GISAXS analysis is the estimation of the paracrystalline distortion factor, which can be useful to evaluate the level of order in the nanostructure. Data revealed that LIPSS in PC 71 BM films can be described as one-dimensional paracrystalline lattices with levels of order in accordance with those typically observed in LIPSS of other materials. The PRI effect leaves a qualitatively similar nanostructure but about two times more disordered than the original LIPSS one. Our results show that GISAXS is a powerful tool to characterize Resist-free Imprinting procedures of potential relevance in nanotechnology. [ABSTRACT FROM AUTHOR]

The stability of fullerene C 60 and Cu–C 60 nanocomposite thin films are measured by exposing to gamma irradiation at different doses ranging from 25 kGy to 100 kGy. FTIR vibrational spectroscopy shows no effect of gamma irradiation on the fullerene C 60 but gives a C C vibration at the highest dose of 100 kGy in Cu–C 60 nanocomposite. The Raman spectroscopy was performed at two different wavelengths (325 nm and 532 nm) to know the structural transformation of fullerene and its nanocomposite thin film. At the wavelength of 532 nm, polymerization of fullerene molecules is observed in Cu–C 60 nanocomposite thin film. UV–visible spectroscopy shows more prominent modes of fullerene C 60 after gamma irradiation. Transmission electron microscopy is used to know the increase in particle size of the nanocomposite thin films. Contact angle measurements are also performed to know the wettability of the gamma irradiated samples. Finally, X-Ray photoelectron spectroscopy is performed to know the elemental state of these samples. • C 60 and Cu–C 60 thin films are irradiated by gamma rays at different doses ranging from 25 to 100 KGy. • The optical and morphological changes were observed. • In Raman spectroscopy (performed at a wavelength of 532 nm) polymerization of fullerene molecule is observed. • Hydrophilic and hydrophobic characteristic of C 60 and Cu–C 60 thin films are also discussed by contact angle measurement. • Copper nanoparticle size increases with the increase in gamma irradiation dose. [ABSTRACT FROM AUTHOR]

We have developed an electron cyclotron resonance ion source apparatus, which is designed for the production of endohedral fullerene. In this study, we irradiated the Fe+ beam to the C60 thin film. We changed the experimental condition of the dose and the ion energy. We could observe the Fe + C60 peak by analysis of the time-of-flight mass spectrometry. The highest intensity of the Fe + C60 peak was observed at the ion energy of 200 eV. The Fe + C60 peak intensity tended to become high in the case of long irradiation time and large dose. [ABSTRACT FROM AUTHOR]

Abstract: 4H-SiC (silicon carbide) films were grown on (0001) sapphire substrate at rather low temperatures(1000–1100°C) with relative high deposition rate by using fullerene (C60) and silicon solid sources molecular beam epitaxy with substrate nitridation and aluminum nitride (AlN) buffer layer deposition prior to the SiC deposition. The effects of substrate nitridation and AlN buffer layer to the adhesion of the SiC thin films on sapphire have been studied. X-Ray diffraction, pole figure, atomic force microscope, Fourier transform infrared spectroscopy and photoluminescence were employed for the analysis of composition, orientation of the film and surface morphology. Relative high deposition rate at ∼165nm/h was achieved. [Copyright &y& Elsevier]

• Anionic polymers were coated on fullerene thin films to suppress their dissolution. • Nafion coating enhanced the durability of up to five redox reactions of C 70. • Nafion provided C 70 with a better barrier function against dissolution than C 60. • SSEBS coating had no adverse effects on the cathodic limit. The dissolution of redox-active molecules on electrodes hinders the durability of the corresponding redox reactions. In this study, we propose the overcoating of anionic polymers as a possible solution to the dissolution problem. Fullerene was chosen as a model redox-active molecule due to its ability to accept multiple electrons. The barrier function of two anionic polymers was evaluated by monitoring the peak currents for the redox reactions of fullerenes using cyclic voltammetry. Nafion exhibited a better barrier effect on the dissolution of fullerene species and stabilized up to four and five redox reactions of C 60 and C 70 , respectively. On the other hand, although sulfonated polystyrene- block -poly(ethylene- ran -butylene)- block -polystyrene showed a more negative cathodic limit in the electrochemical potential window, the dissolution of fullerene species occurred as fast as for uncovered fullerene thin films. [ABSTRACT FROM AUTHOR]

The C 60 /glass, C 60 /Si, C 60 /porous Si/Si as well as porous Si/Si thin film structures for comparison were prepared and studied by photoluminescence spectroscopy at room temperature. Along with a broad-band low-energy emission at 1.774 eV in the photon energy range of the nominaly forbidden optical transitions, the C 60 films on glass substrate exhibit high-energy emissions at 2.115 eV and 2. 342 eV in the range of allowed dipole transititions. On the other hand, C 60 films on Si or porous Si/Si display only the 1.774 eV emission band. The intensity of this emission in C 60 /porous Si/Si is 200 times higher than that in C 60 /Si and at least 20 times exceeds the one for the emission observed on porous Si/Si. Such a dramatic increase in emission intensity is indicative of the relaxation of the selection rules for nominally forbidden optical transitions and suggests strong interaction of C 60 molecules with porous silicon walls. Molecular signatures of the C 60 films are clearly manifested by the vibronic transitions with 60 meV energy separation (A g -mode energy) between the irradiative levels, observed on 1.774 eV emission band in C 60 /porous Si/Si. The origin of the 2.115 and 2.342 eV emission bands is analyzed within a standard band insulator approach, together with the obtained ellipsometric data. The first corresponds to the band-to-band transitions at band gap. The appearance of the second can be related to the splitting of the valence band in the X point of the Brillouin zone of C 60 film due to the crystal field. The strength of the crystal field splitting is then ~ 200 meV. • C 60 fullerene layers on various substrates are obtained and thoroughly characterized. • C 60 thin film is a direct gap band insulator with band gap energy of 2.115 eV. • Vibronic levels of singlet Frenkel excitons are involved in emission below 2 eV. • 200 times enhanced emission below 2 eV is observed on C 60 film/porous Si/Si structures. [ABSTRACT FROM AUTHOR]

In ferromagnetic (FM) metal/organic semiconductor (OSC) heterostructures charge transfer can occur which leads to induction of magnetism in the non-magnetic OSC. This phenomenon has been described by the change in the density of states in the OSC which leads to a finite magnetic moment at the OSC interface and it is called the ‘spinterface’. One of the main motivations in this field of organic spintronics is how to control the magnetic moment in the spinterface. In this regard, there are several open questions such as (i) which combination of FM and OSC can lead to more moment at the spinterface? (ii) Is the thickness of OSC also important? (iii) How does the spinterface moment vary with the FM thickness? (iv) Does the crystalline quality of the FM matter? (v) What is the effect of spinterface on magnetization reversal, domain structure and anisotropy? In this context, we have tried to answer the last four issues in this paper by studying Fe/C60 bilayers of variable Fe thickness deposited on Si substrates. We find that both the induced moment and thickness of the spinterface vary proportionally with the Fe thickness. Such behavior is explained in terms of the growth quality of the Fe layer on the native oxide of the Si (100) substrate. The magnetization reversal, domain structure and anisotropy of these bilayer samples were studied and compared with their respective reference samples without the C60 layer. It is observed that the formation of spinterface leads to a reduction in uniaxial anisotropy in Fe/C60 on Si (100) in comparison to their reference samples. [ABSTRACT FROM AUTHOR]

A fullerene field-effect transistor (FET) device has been fabricated with thin films of C88, and n-channel normally on depletion-type FET properties have been found in this FET device. The C88 FET exhibited a high mobility, μ, of 2.5×10-3 cm2 V-1 s-1 at 300 K, in fullerene FETs. The carrier transport showed a thermally activated hopping transport. The n-channel normally on FET properties and the hopping transport reflect the small mobility gap and low carrier concentration in the channel region of C88 thin films. [ABSTRACT FROM AUTHOR]

Abstract: The growth of pentacene on C60 film has been studied in real-time by low energy electron microscope. The standing-up phase overgrows on the lying-down phase at room temperature with increasing film thickness. At intermediate temperature we observed two distinct types of nucleation: an earlier nucleation of lying-down phase and a delayed nucleation of standing-up phase on the bare C60 surface between islands of lying-down phase. Further thermal activation control enabled us to tune the types of nucleation and the standing-up phase without co-presence of the lying-down phase could be achieved above ∼70°C. [Copyright &y& Elsevier]