Optimizing PMMA solutions to suppress contamination in the transfer of CVD graphene for batch production

• Chun-Da Liao,
• Andrea Capasso,
• Tiago Queirós,
• Telma Domingues,
• Fatima Cerqueira,
• Nicoleta Nicoara,
• Jérôme Borme,
• Paulo Freitas and
• Pedro Alpuim

Beilstein J. Nanotechnol. 2022, 13, 796–806, doi:10.3762/bjnano.13.70

• of both a graphene film and a single crystal (Figure 2a,b). The area analysis (650 × 500 µm2) revealed less than ten residues, indicating an extremely clean transfer process. B2 PMMA allowed for up to six transfer cycles, representing an intermediate, yet acceptable, mechanical support. This proves

• transfer process. Following this method, the Cu substrate with graphene was first oxidized in ambient air on a hot plate at 200 °C for 2 min. The graphene film on the Cu substrate serves as a protection layer, preventing the underlying Cu surface from oxidation because of its high chemical/thermal

• , on which the graphene film would make electrical contact. The B2 PMMA/graphene films were then transferred onto the wafer and patterned by O2 plasma, followed by the sacrificial layer removal. Previous to the passivation, Al2O3 was selectively removed to improve the adhesion of the oxide passivation

Reliable fabrication of transparent conducting films by cascade centrifugation and Langmuir–Blodgett deposition of electrochemically exfoliated graphene

• Teodora Vićentić,
• Stevan Andrić,
• Vladimir Rajić and
• Marko Spasenović

Beilstein J. Nanotechnol. 2022, 13, 666–674, doi:10.3762/bjnano.13.58

• quantitatively compared to results found in literature that are obtained using other, more complex graphene film fabrication methods, and is found to occur with a percolation exponent and percolative figure of merit that are of the same order as results in literature. A maximum optical transparency of 82.4% at a

• light path. Graphene film resistance was measured by inserting the substrates with electrodes into an electrode connector (DRP-CACIDE, Metrohm, Oviedo, Spain) and the acquiring resistance with a handheld digital multimeter. Optical dark-field microscopy of the films was performed with a magnification of

• the substrate completely. To analyze the electrical properties of the synthesized graphene films, resistance values of each film were measured. Resistance values, optical transparency values, and the average number of layers in each graphene film are shown in Table 2. A larger number of graphene

Recent progress in actuation technologies of micro/nanorobots

• Ke Xu and
• Bing Liu

Beilstein J. Nanotechnol. 2021, 12, 756–765, doi:10.3762/bjnano.12.59

• controlled, so as to make the robot move along the surface of a graphene film in a desired trajectory. This study provided a lot of useful insight in the design of nanorobots. In the future, such designed nanorobots could be integrated into a silicon-based chip to perform specific actions. Also they could be

Direct growth of few-layer graphene on AlN-based resonators for high-sensitivity gravimetric biosensors

• Jimena Olivares,
• Teona Mirea,
• Lorena Gordillo-Dagallier,
• Bruno Marco,
• José Miguel Escolano,
• Marta Clement and
• Enrique Iborra

Beilstein J. Nanotechnol. 2019, 10, 975–984, doi:10.3762/bjnano.10.98

• stage, carbon atoms segregated from the Ni film to form the graphene layer on its surface. The cooling rate was critical because the graphene film maintains a quasi-equilibrium with the atmosphere and the carbon inside the Ni film. The number of layers of the resulting graphene depended on the cooling

Wearable, stable, highly sensitive hydrogel–graphene strain sensors

• Jian Lv,
• Chuncai Kong,
• Chao Yang,
• Lu Yin,
• Itthipon Jeerapan,
• Fangzhao Pu,
• Xiaojing Zhang,
• Sen Yang and
• Zhimao Yang

Beilstein J. Nanotechnol. 2019, 10, 475–480, doi:10.3762/bjnano.10.47

• hydrogel over a wider temperature range, but also increases the stretchability of the hydrogel from 800% to 2000%. The enhanced sensitivity can be attributed to the graphene film, whereby the graphene flakes redistribute to optimize the contact area under different strains. The careful design enables this

• -sensitivity, graphene-based, water/glycerol (WG) binary-solvent hydrogel (graphene/WG-hydrogel) strain sensor is designed via a two-step method. Water and glycerol are used as solvents to synthesize the hydrogel substrate with long-lasting moisture-retaining properties [12]. The continuous graphene film is

• cast onto the hydrogel through drop casting and drying. Although the bare hydrogel already shows resistance changes with respect to strain, the graphene film was used to further increase the sensitivity. The graphene/WG-hydrogel strain sensor can be used to sense human finger movements. This stable

Effects of post-lithography cleaning on the yield and performance of CVD graphene-based devices

• Eduardo Nery Duarte de Araujo,
• Thiago Alonso Stephan Lacerda de Sousa,
• Luciano de Moura Guimarães and
• Flavio Plentz

Beilstein J. Nanotechnol. 2019, 10, 349–355, doi:10.3762/bjnano.10.34

• LOR in a step-by-step manner, using a second procedure, called P2. At first, the photoresist was removed by 1-methoxy-2-propanol acetate (PGMEA), a solvent towards which LOR is inert (Figure 2d,e). Then, the remaining LOR layer that covered the graphene film, was removed in AZ351B (1:4) (Figure 2f

New 2D graphene hybrid composites as an effective base element of optical nanodevices

• Olga E. Glukhova,
• Igor S. Nefedov,
• Alexander S. Shalin and
• Мichael М. Slepchenkov

Beilstein J. Nanotechnol. 2018, 9, 1321–1327, doi:10.3762/bjnano.9.125

• of graphene ripple during the formation of the hybrid nanocomposite. As a result, the intensity of the peaks of the CNT–graphene film is higher than that of pure graphene and individual nanotubes (for details see Figure 6 in [14]). Special attention should be paid to the peak of great intensity

• , the established regularities of change in absorbance as a function of the angle of incidence of the electromagnetic wave allows us to suggest the possibility of using the CNT–graphene film as a polarizer for electro-optical and magneto-optical thin film modulators. The advantages of such polarizers

The electrical conductivity of CNT/graphene composites: a new method for accelerating transmission function calculations

• Olga E. Glukhova and
• Dmitriy S. Shmygin

Beilstein J. Nanotechnol. 2018, 9, 1254–1262, doi:10.3762/bjnano.9.117

• X-axis and 2.13 nm along the Y-axis for each unit cell. Figure 5a shows the atomic structure of a pillared graphene film with an inter-tube distance of 2.1 nm. The tubes are connected seamlessly with graphene, i.e., the CNT smoothly passes into the graphene sheet, and the junction contains not only

• (9,9) at the same distance between tubes of 2.1 nm. The conductance and resistance of the pillared graphene film were calculated based on the calculated T(E). Table 1 shows the corresponding data: tube length, number of atoms in the transmitted cell, calculated Fermi level, conductance and resistance

• conclude that for the single-layer pillared graphene film, the resistance in the direction of the Y-axis (zigzag edge of the graphene sheet) varies insignificantly and does not depend on the distance between the graphene layers. For a two-layer composite, the average resistance depends on the axis

Electro-optical characteristics of a liquid crystal cell with graphene electrodes

• Nune H. Hakobyan,
• Hakob L. Margaryan,
• Valeri K. Abrahamyan,
• Vladimir M. Aroutiounian,
• Arpi S. Dilanchian Gharghani,
• Amalya B. Kostanyan,
• Timothy D. Wilkinson and
• Nelson Tabirian

Beilstein J. Nanotechnol. 2017, 8, 2802–2806, doi:10.3762/bjnano.8.279

• . Results and Discussion Synthesis of graphene films The graphene was obtained by a chemical vapor deposition (CVD) process. Details of synthesis and extensive characterization of the CVD graphene can be found in prior works [13][14]. The monolayer graphene film was then transferred from the Cu foil to a

The integration of graphene into microelectronic devices

• Guenther Ruhl,
• Sebastian Wittmann,
• Matthias Koenig and
• Daniel Neumaier

Beilstein J. Nanotechnol. 2017, 8, 1056–1064, doi:10.3762/bjnano.8.107

• diffusion barrier, it suffers from the diffusion of Si from the substrate towards the Cu surface generating holes in the graphene film. Decreasing the deposition temperature to below 800 °C can improve the defect level but cannot completely eliminate it [10]. Also the transfer onto a dielectric substrate

• graphene film. Lowering the deposition temperature would be also beneficial here. Several approaches have been reported [14][15][16][17][18], but have not been shown yet to yield an acceptable graphene quality. In history, the first transfer technique for graphene films from the CVD growth substrate was

• processes, the metal underetch times are rather long, even when the graphene film is patterned to provide distributed access for the etch medium. A technique that copes with this problem is the so-called “bubble transfer”, which uses the generation of electrochemically generated hydrogen bubbles at the

Study of the correlation between sensing performance and surface morphology of inkjet-printed aqueous graphene-based chemiresistors for NO₂ detection

• F. Villani,
• C. Schiattarella,
• T. Polichetti,
• R. Di Capua,
• F. Loffredo,
• B. Alfano,
• M. L. Miglietta,
• E. Massera,
• L. Verdoliva and
• G. Di Francia

Beilstein J. Nanotechnol. 2017, 8, 1023–1031, doi:10.3762/bjnano.8.103

• IJP layer in D-P17 with respect to D-P25 and thus to the higher surface-to-volume ratio of the graphene film in D-P17. In addition, the thickness of the film can have repercussions also on its morphology, as deeply analysed afterwards by AFM analysis, since a thinner layer retraces more accurately the

CVD transfer-free graphene for sensing applications

• Chiara Schiattarella,
• Sten Vollebregt,
• Tiziana Polichetti,
• Brigida Alfano,
• Ettore Massera,
• Maria Lucia Miglietta,
• Girolamo Di Francia and
• Pasqualina Maria Sarro

Beilstein J. Nanotechnol. 2017, 8, 1015–1022, doi:10.3762/bjnano.8.102

• Si technology, is of crucial importance [14][15]. A possible choice for the synthesis of large-area graphene is the metal-assisted hydrocarbon dissociation and/or the deposition method from solid carbon sources. In both cases, after the growth the graphene film needs to be transferred onto other

• structurally characterized in a previous work [24], from which it emerged that the average number of layers was about 20. The material showed to be free from metal impurities after Mo removal and not damaged by the lift-off process. The quality of the graphene film has been monitored via Raman spectroscopy

• different sites of the graphene film. As can be seen in Figure 2, the spectra display a fair uniformity. In particular, the arising of the D (ca. 1350 cm−1) and D′ (ca. 1600 cm−1) bands is related to presence of defects and in particular the D intensity, roughly 5-fold lower than that of the G peak, attests

Graphene functionalised by laser-ablated V₂O₅ for a highly sensitive NH₃ sensor

• Margus Kodu,
• Artjom Berholts,
• Tauno Kahro,
• Mati Kook,
• Peeter Ritslaid,
• Helina Seemen,
• Tea Avarmaa,
• Harry Alles and
• Raivo Jaaniso

Beilstein J. Nanotechnol. 2017, 8, 571–578, doi:10.3762/bjnano.8.61

• allowed to cool slowly, 15 °C/min in Ar flow. The as-grown graphene film was transferred onto a Si/SiO2 substrate by using poly(methyl methacrylate) (PMMA; MW ≈997,000 Da, GPC, Alfa Aesar) as a supporting material. The PMMA solution (1% in chlorobenzene) was spin-coated onto graphene/Cu, dried, and the Cu

• foil was dissolved in ammonium persulfate solution overnight. The floating PMMA/graphene film was rinsed with deionized water and transferred onto the Si/SiO2 substrate (see Figure 6) equipped with Pt electrodes (60 nm thick) that were deposited through a shadow mask by magnetron sputtering. The gap

Advances in the fabrication of graphene transistors on flexible substrates

• Gabriele Fisichella,
• Stella Lo Verso,
• Silvestra Di Marco,
• Vincenzo Vinciguerra,
• Emanuela Schilirò,
• Salvatore Di Franco,
• Raffaella Lo Nigro,
• Fabrizio Roccaforte,
• Amaia Zurutuza,
• Alba Centeno,
• Sebastiano Ravesi and
• Filippo Giannazzo

Beilstein J. Nanotechnol. 2017, 8, 467–474, doi:10.3762/bjnano.8.50

• demonstrates that the previously discussed LT process is completely compatible with the final plastic substrate. Graphene transistor channels were fabricated starting from a single layer graphene film grown by CVD on large area copper foils (provided by Graphenea). The graphene membrane was transferred to a

Nitrogen-doped twisted graphene grown on copper by atmospheric pressure CVD from a decane precursor

• Ivan V. Komissarov,
• Nikolai G. Kovalchuk,
• Vladimir A. Labunov,
• Ksenia V. Girel,
• Olga V. Korolik,
• Mikhail S. Tivanov,
• Algirdas Lazauskas,
• Mindaugas Andrulevičius,
• Tomas Tamulevičius,
• Viktoras Grigaliūnas,
• Šarunas Meškinis,
• Sigitas Tamulevičius and
• Serghej L. Prischepa

Beilstein J. Nanotechnol. 2017, 8, 145–158, doi:10.3762/bjnano.8.15

• dissolved in a water solution of FeCl3. The graphene film was gently washed several times in a bath with distilled water prior to the transfer onto the substrate. Characterization The graphene samples were analyzed by Raman spectroscopy using the Nanofinder HE with 532 nm and 473 nm excitation wavelengths

Graphene–polymer coating for the realization of strain sensors

• Carmela Bonavolontà,
• Carla Aramo,
• Massimo Valentino,
• Giampiero Pepe,
• Sergio De Nicola,
• Gianfranco Carotenuto,
• Angela Longo,
• Mariano Palomba,
• Simone Boccardi and
• Carosena Meola

Beilstein J. Nanotechnol. 2017, 8, 21–27, doi:10.3762/bjnano.8.3

• described a simple fabrication process to produce a low-cost graphene film on a PMMA substrate. The process makes use of the direct application of a nanostructured graphite colloidal suspension to a PMMA slat. Bending tests have been performed on this structure in order to study its piezoelectric response

Synthesis and applications of carbon nanomaterials for energy generation and storage

• Marco Notarianni,
• Jinzhang Liu,
• Kristy Vernon and
• Nunzio Motta

Beilstein J. Nanotechnol. 2016, 7, 149–196, doi:10.3762/bjnano.7.17

• diffusion of C atoms in Cu is very low (0.001 atom % at 1000 °C) [83][142]. The CVD process on Cu foils can be scaled using a roll-to-roll technique, allowing for a 30 inch graphene film for a transparent electrode (Figure 22a) [82]. However, even this method does not guarantee perfect graphene in terms of

Nitrogen-doped graphene films from chemical vapor deposition of pyridine: influence of process parameters on the electrical and optical properties

• Andrea Capasso,
• Theodoros Dikonimos,
• Francesca Sarto,
• Alessio Tamburrano,
• Giovanni De Bellis,
• Maria Sabrina Sarto,
• Giuliana Faggio,
• Angela Malara,
• Giacomo Messina and
• Nicola Lisi

Beilstein J. Nanotechnol. 2015, 6, 2028–2038, doi:10.3762/bjnano.6.206

• grown by pyridine (0.92 at 1 sccm H2 and 1.16 at 100 sccm H2) are consistently higher than those of the ethanol samples (0.68 at 1 sccm H2 and 0.25 at 100 sccm H2). This ID/IG increment for pyridine-CVD might be thus ascribed to the insertion of nitrogen in the graphene film. It was shown that the ID/ID

• at about 20 °C and then transferred in a clean distilled water bath for rinsing. The graphene film was finally scooped out of the distilled water using the destination substrate for its subsequent characterization and use. Film characterization Raman spectroscopy Doping level, degree of sp2

Cathode lens spectromicroscopy: methodology and applications

• T. O. Menteş,
• G. Zamborlini,
• A. Sala and
• A. Locatelli

Beilstein J. Nanotechnol. 2014, 5, 1873–1886, doi:10.3762/bjnano.5.198

• direction. By cooling the sample from growth to room temperature, a phase transformation occurs in the graphene film, which develops neighboring phases characterized by flat and buckled morphology. Adjacent striped-shaped domains of different carbon surface density alternate on the film at microscopic

• those of observed on Ir(100). Instead, LEEM imaging at high lateral resolution evidenced the formation of wrinkles in the graphene film, a process which helps relieving the thermal strain, because of the different thermal contraction of film and substrate. Similar features have been previously observed

Carbon-based smart nanomaterials in biomedicine and neuroengineering

• Antonina M. Monaco and
• Michele Giugliano

Beilstein J. Nanotechnol. 2014, 5, 1849–1863, doi:10.3762/bjnano.5.196

• enhanced compared to the use of conventional graphene film electrode; this was due to the larger specific surface area of the three-dimensional scaffold. Conclusion In this review, several reasons were established for why carbon-based nanomaterials have gained more importance over the past few years in the

Intermolecular vs molecule–substrate interactions: A combined STM and theoretical study of supramolecular phases on graphene/Ru(0001)

• Michael Roos,
• Benedikt Uhl,
• Daniela Künzel,
• Harry E. Hoster,
• Axel Groß and
• R. Jürgen Behm

Beilstein J. Nanotechnol. 2011, 2, 365–373, doi:10.3762/bjnano.2.42

• exclusively populated the areas between the maxima of the moiré structure of the buckled graphene layer. The consequences for the competing intermolecular interactions and corrugation in the adsorption potential are discussed and compared with the theoretical results. Keywords: graphene film; intermolecular

• pattern (Figure 1a) and resolve the atomic structure in the high resolution image (Figure 1b). In the latter image, two different areas are marked, denoting the positions on top of the maxima of the moiré lattice of the graphene film (“hill positions” - H) and the lower parts between the maxima (“valley

• positions” - V). These are taken as representative for the different adsorption sites on the graphene/Ru(0001) surface. Recently, we demonstrated, for the adsorption of 2-phenyl-4,6-bis(6-(pyridin-2-yl)-4-(pyridin-4-yl)pyridin-2-yl)pyrimidine (2,4’-BTP) molecules on a Ru(0001) supported graphene film, that