Nanoarchitectonics meets cell surface engineering: shape recognition of human cells by halloysite-doped silica cell imprints

• Elvira Rozhina,
• Ilnur Ishmukhametov,
• Svetlana Batasheva,
• Farida Akhatova and
• Rawil Fakhrullin

Beilstein J. Nanotechnol. 2019, 10, 1818–1825, doi:10.3762/bjnano.10.176

• organic cell debris was removed by treatment with aqueous HNO3 and HCl mixture (3:1) and washed thoroughly with water. This procedure yielded polydisperse (100 nm to 1 µm) cell-templated imprints with diverse morphology. Typical AFM and SEM images of the imprints are shown in Figure 4A–C. We have also

• Milli-Q, and studied with AFM and SEM. Cells recognition by imprints The recognition of HeLa cells with imprints was visualised using bright-field optical microscopy (Axio Imager Z2, Carl Zeiss), and laser confocal microscopy (LSM 780: 405 nm and 633 nm lasers). For fluorescence microscopy imaging

Growth dynamics and light scattering of gold nanoparticles in situ synthesized at high concentration in thin polymer films

• Corentin Guyot,
• Philippe Vandestrick,
• Ingrid Marenne,
• Olivier Deparis and
• Michel Voué

Beilstein J. Nanotechnol. 2019, 10, 1768–1777, doi:10.3762/bjnano.10.172

• the roughness of the films using atomic force microscopy (AFM). Results and Discussion Optical scattering measurements In preliminary experiments, Au-doped polymer films coated on glass were annealed in an oven at different temperatures (90–160 °C) over different periods of time (1–12 h). Different

• optical scattering of the laser beam strongly increased (Figure 2). This phenomenon can be related to the roughness parameter observed in AFM measurements as explained in the next subsection. The most general way to characterize optically a surface is to measure its bi-directional reflection distribution

• were imaged by AFM. A typical image of 5 μm × 5 μm size is presented in Figure 5a. It unambiguously shows the presence of the AuNPs. The topography of the samples was characterized by the average surface roughness parameter (Sa) and by the root-mean-square surface roughness parameter (Sq). For the

Remarkable electronic and optical anisotropy of layered 1T’-WTe₂ 2D materials

• Qiankun Zhang,
• Rongjie Zhang,
• Jiancui Chen,
• Wanfu Shen,
• Chunhua An,
• Xiaodong Hu,
• Mingli Dong,
• Jing Liu and
• Lianqing Zhu

Beilstein J. Nanotechnol. 2019, 10, 1745–1753, doi:10.3762/bjnano.10.170

• following way: where R2 and R1 are the reflectance coefficients associated with the natural orthorhombic crystal. To characterize the optical anisotropy, a few layered 1T’-WTe2 flake was mechanically exfoliated and transferred onto a pre-cleaned Si/SiO2 wafer, and atomic force microscopy (AFM) was used to

• Tecnai F20 platform with an acceleration voltage of 200 kV. A HORIBA HR800 Raman spectrometer equipped with a 532 nm wavelength laser was used for the Raman spectroscopy analysis. Additionally, the thickness of 1T’-WTe2 was confirmed using AFM (Bruker Dimension Icon) based on the sample thickness

• 1T’-WTe2 flake. Identification of the lattice anisotropy of an exfoliated 1T’-WTe2 flake. a) AFM image of the 1T’-WTe2 flake transferred onto a Si/SiO2 substrate by mechanical exfoliation. The heights of zone 1 and zone 2 are 16.36 nm and 5.25 nm, respectively. b) ADRDM results of the same WTe2 flake

Subsurface imaging of flexible circuits via contact resonance atomic force microscopy

• Wenting Wang,
• Chengfu Ma,
• Yuhang Chen,
• Lei Zheng,
• Huarong Liu and
• Jiaru Chu

Beilstein J. Nanotechnol. 2019, 10, 1636–1647, doi:10.3762/bjnano.10.159

• , Anhui, China 10.3762/bjnano.10.159 Abstract Subsurface imaging of Au circuit structures embedded in poly(methyl methacrylate) (PMMA) thin films with a cover thickness ranging from 52 to 653 nm was carried out by using contact resonance atomic force microscopy (CR-AFM). The mechanical difference of the

• embedded metal layer leads to an obvious CR-AFM frequency shift and therefore its unambiguous differentiation from the polymer matrix. The contact stiffness contrast, determined from the tracked frequency images, was employed for quantitative evaluation. The influence of various parameter settings and

• calculations provide a guide to optimizing parameter settings for the nondestructive diagnosis of flexible circuits. Defect detection of the embedded circuit pattern was also carried out, which indicates the capability of imaging tiny subsurface structures smaller than 100 nm by using CR-AFM. Keywords: atomic

Kelvin probe force microscopy work function characterization of transition metal oxide crystals under ongoing reduction and oxidation

• Dominik Wrana,
• Karol Cieślik,
• Wojciech Belza,
• Christian Rodenbücher,
• Krzysztof Szot and
• Franciszek Krok

Beilstein J. Nanotechnol. 2019, 10, 1596–1607, doi:10.3762/bjnano.10.155

• obtaining work function and conductivity maps on the same area by combining noncontact and contact modes of atomic force microscopy (AFM). As most of the real applications require ambient operating conditions, we have additionally checked the impact of air venting on the work function of the TiO/SrTiO3(100

• method employing KPFM and local conductivity AFM for the characterization of the work function of transition metal oxides may help in understanding the impact of reduction and oxidation on electronic properties, which is of high importance in the development of effective sensing and catalytic devices

• possibility of obtaining full information on the electronic properties when the KPFM technique is accompanied by local conductivity atomic force microscopy (LC-AFM). This is followed by a discussion of the significant variations of the WF within cubic TiO nanowires, the estimation of the KPFM resolution and

Materials nanoarchitectonics at two-dimensional liquid interfaces

• Katsuhiko Ariga,
• Michio Matsumoto,
• Taizo Mori and
• Lok Kumar Shrestha

Beilstein J. Nanotechnol. 2019, 10, 1559–1587, doi:10.3762/bjnano.10.153

Development of a new hybrid approach combining AFM and SEM for the nanoparticle dimensional metrology

• Loïc Crouzier,
• Alexandra Delvallée,
• Sébastien Ducourtieux,
• Laurent Devoille,
• Guillaume Noircler,
• Christian Ulysse,
• Olivier Taché,
• Elodie Barruet,
• Christophe Tromas and
• Nicolas Feltin

Beilstein J. Nanotechnol. 2019, 10, 1523–1536, doi:10.3762/bjnano.10.150

• proposes a new approach of hybrid metrology taking advantage of the complementary nature of atomic force microscopy (AFM) and scanning electron microscopy (SEM) techniques for measuring the main characteristic parameters of nanoparticle (NP) dimensions in 3D. The NP area equivalent, the minimal and the

• maximal Feret diameters are determined by SEM and the NP height is measured by AFM. In this context, a kind of new NP repositioning system consisting of a lithographed silicon substrate has been specifically developed. This device makes it possible to combine AFM and SEM size measurements performed

• equality between their height and their lateral diameters. However, discrepancies between AFM and SEM measurements have been observed, showing significant deviation from sphericity as a function of the nanoparticle size. Keywords: AFM; hybrid metrology; nanoparticles; SEM; size distribution; uncertainty

Kelvin probe force microscopy of the nanoscale electrical surface potential barrier of metal/semiconductor interfaces in ambient atmosphere

• Petr Knotek,
• Tomáš Plecháček,
• Jan Smolík,
• Petr Kutálek,
• Filip Dvořák,
• Milan Vlček,
• Jiří Navrátil and
• Čestmír Drašar

Beilstein J. Nanotechnol. 2019, 10, 1401–1411, doi:10.3762/bjnano.10.138

• nanosheets through the reaction with the Bi2Se3. The Schottky barrier formed by the 1D and 2D nanoinclusions was characterized by means of atomic force microscopy (AFM). We used Kelvin probe force microscopy (KPFM) in ambient atmosphere at the nanoscale and compared the results to those of ultraviolet

• harm to other transport parameters. The characterization of NIs or NPs in TE materials is realized most frequently by the different modes of atomic force microscopy (AFM): i) by comparing the conductivity/resistivity (CAFM) or I–V curves measurement in the direct-contact of the conductive tip and the

• tunneling microscopy (STM) [27][28] or by using AFM in the semicontact mode. The latter enables a describtion not only of the topography (size and shape) but also a detection of the changes in density, stiffness and adhesion of NPs [20][21][24][29][30]. In the present study we demonstrate that the Schottky

Nanoscale spatial mapping of mechanical properties through dynamic atomic force microscopy

• Zahra Abooalizadeh,
• Leszek Josef Sudak and
• Philip Egberts

Beilstein J. Nanotechnol. 2019, 10, 1332–1347, doi:10.3762/bjnano.10.132

• Zahra Abooalizadeh Leszek Josef Sudak Philip Egberts Department of Mechanical and Manufacturing Engineering, University of Calgary, 40 Research Place NW, Calgary, Alberta T2L 1Y6, Canada 10.3762/bjnano.10.132 Abstract Dynamic atomic force microscopy (AFM) was employed to spatially map the elastic

• modulus of highly oriented pyrolytic graphite (HOPG), specifically by using force modulation microscopy (FMM) and contact resonance (CR) AFM. In both of these techniques, a variation in the amplitude signal was observed when scanning over an uncovered step edge of HOPG. In comparison, no variation in the

• (CR) AFM; elastic modulus mapping; force modulation microscopy (FMM); highly oriented pyrolytic graphite (HOPG); mechanical properties; surface science; surface steps; Introduction In recent years, the study of the size-dependent properties of materials, and in particular those at the nanometer scale

Imaging the surface potential at the steps on the rutile TiO₂(110) surface by Kelvin probe force microscopy

• Masato Miyazaki,
• Huan Fei Wen,
• Quanzhen Zhang,
• Yuuki Adachi,
• Jan Brndiar,
• Ivan Štich,
• Yan Jun Li and
• Yasuhiro Sugawara

Beilstein J. Nanotechnol. 2019, 10, 1228–1236, doi:10.3762/bjnano.10.122

• function between the tip and the sample, on the basis of atomic force microscopy (AFM) [39][40]. Since the CPD strongly depends on the charge distribution on the surface, KPFM allows us to investigate the electrostatic properties of surfaces [41][42][43]. In this study, we measured the CPD around the steps

• out with a custom-built ultrahigh-vacuum noncontact atomic force microscopy (NC-AFM) system operated at a temperature of 78 K with a base pressure below 4 × 10−11 mbar. The NC-AFM system was operated in the frequency-modulation mode [44] with a constant cantilever oscillation amplitude (5 Å). The

• the fAC component of the electrostatic force, providing the CPD value (VCPD). The topography and CPD were measured sequentially using the lift-mode technique to minimize crosstalk [47]. In this scanning mode, the topography (z) is scanned in the first trace using AFM and immediately retraced with a

Influence of dielectric layer thickness and roughness on topographic effects in magnetic force microscopy

• Alexander Krivcov,
• Jasmin Ehrler,
• Marc Fuhrmann,
• Tanja Junkers and
• Hildegard Möbius

Beilstein J. Nanotechnol. 2019, 10, 1056–1064, doi:10.3762/bjnano.10.106

• of the resist using the AR 300-12 thinner (Allresist). The layer thickness and the degree of dilutions are shown in Table S1 (Supporting Information File 1). The thickness of the layers was measured using the AFM tip-scratch method. Phase shift as a function of the tip–substrate distance z

Revisiting semicontinuous silver films as surface-enhanced Raman spectroscopy substrates

• Malwina Liszewska,
• Bogusław Budner,
• Małgorzata Norek,
• Bartłomiej J. Jankiewicz and
• Piotr Nyga

Beilstein J. Nanotechnol. 2019, 10, 1048–1055, doi:10.3762/bjnano.10.105

• . Absorption was calculated assuming the sum of transmittance, reflectance, and absorption is 100%. The morphology of the fabricated structures was measured using a Quanta 3D FEG Dual Beam scanning electron microscope (SEM) and an atomic force microscope (AFM). The SEM images of SSFs were converted to black

• and white and metal coverage was calculated. The AFM maps were collected using an NTEGRA atomic force microscope from NT-MDT company. The surface topography measurements were made in semi-contact mode. We used HA_NC ETALON (NT-MDT) probe with 140 kHz ± 10% resonant frequency, force constant of 3.5 N/m

• hypothetical sample between sample F and G (as for sample F we do not observe continuous silver path and for sample G several paths across the SEM image exist). In order to determine the physical thickness of the SSFs we carried out AFM studies (data presented in Table 1). For each of the SSFs a part of the

Tailoring the stability/aggregation of one-dimensional TiO₂(B)/titanate nanowires using surfactants

• Atiđa Selmani,
• Johannes Lützenkirchen,
• Kristina Kučanda,
• Dario Dabić,
• Engelbert Redel,
• Ida Delač Marion,
• Damir Kralj,
• Darija Domazet Jurašin and
• Maja Dutour Sikirić

Beilstein J. Nanotechnol. 2019, 10, 1024–1037, doi:10.3762/bjnano.10.103

• ) micrographs revealed that the synthesized TNWs have a distinct, straight, wire-like morphology (Figure 1a). The analysis of the micrographs showed that the length of the TNWs is in the range from 900 to 2000 nm, while the measured diameter ranged from 25 to 250 nm. Atomic force microscopy (AFM) revealed the

• tendency of the material to form bundles from a pair of (or more) TNWs (Figure 1b). However, single TNWs were also visible. From the AFM topographs the diameter of a single TNW has been estimated to vary between 25 and 175 nm, while the length varied from rather short fragments (50 nm) to much longer TNWs

• resolution of the Raman spectrometer was 4 cm−1. The morphology of the TNWs was visualized by using high-resolution scanning electron microscopy Zeiss HR-SEM (Gemini Class) at 3–5 kV. AFM imaging was performed with a Nanosurf Flex AFM in dynamic force mode (simultaneously acquiring topography, amplitude and

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

• surface of the Ni film suffered from restructuration during the CVD process that strongly depended on the heating rate. In order to assess the surface of the films after the growth of graphene, the samples were analysed by atomic force microscopy (AFM) using a Molecular Imaging Pico LE apparatus operated

• in contact mode; AFM images are shown in Figure 1. Compared with the surface of the bare Ni surface (Figure 1a), high heating rates induce the partial dewetting of the Ni layer (Figure 1b), which displays a non-uniform thickness distribution, combining areas with hillocks and areas with voids

• and the resonant frequency identified. This process was controlled with a LabVIEW® application that allowed assessing the frequency with less than 1 kHz accuracy each 7 s. Figure 10 shows the experimental setup. 3D AFM image of the surface of the Ni film: a) as grown, b) after graphene growth with a

In situ AFM visualization of Li–O₂ battery discharge products during redox cycling in an atmospherically controlled sample cell

• Kumar Virwani,
• Younes Ansari,
• Khanh Nguyen,
• Francisco José Alía Moreno-Ortiz,
• Jangwoo Kim,
• Maxwell J. Giammona,
• Ho-Cheol Kim and
• Young-Hye La

Beilstein J. Nanotechnol. 2019, 10, 930–940, doi:10.3762/bjnano.10.94

• /bjnano.10.94 Abstract The in situ observation of electrochemical reactions is challenging due to a constantly changing electrode surface under highly sensitive conditions. This study reports the development of an in situ atomic force microscopy (AFM) technique for electrochemical systems, including the

• design, fabrication, and successful performance of a sealed AFM cell operating in a controlled atmosphere. Documentation of reversible physical processes on the cathode surface was performed on the example of a highly reactive lithium–oxygen battery system at different water concentrations in the solvent

• . The AFM data collected during the discharge–recharge cycles correlated well with the simultaneously recorded electrochemical data. We were able to capture the formation of discharge products from correlated electrical and topographical channels and measure the impact of the presence of water. The cell

Nanoscale optical and structural characterisation of silk

• Meguya Ryu,
• Reo Honda,
• Adrian Cernescu,
• Arturas Vailionis,
• Armandas Balčytis,
• Jitraporn Vongsvivut,
• Jing-Liang Li,
• Denver P. Linklater,
• Elena P. Ivanova,
• Vygantas Mizeikis,
• Mark J. Tobin,
• Junko Morikawa and
• Saulius Juodkazis

Beilstein J. Nanotechnol. 2019, 10, 922–929, doi:10.3762/bjnano.10.93

• different methods, i.e., (i) a table-top Fourier-transform infrared (FTIR) transmission spectrometer, (ii) a synchrotron-based attenuated total reflection (ATR) FTIR spectrometer, and (iii) an atomic force microscopy (AFM) tip responding to the absorbed IR light (nano-IR [9]), produced comparable spectral

• features [10]. Whilst the first two modalities probe micrometer-sized volumes of silk, the AFM-based nano-IR technique acquires structural information at the nanoscale (i.e., the area under the AFM tip from a volume with a lateral cross section of ca. 20 nm). Differences in absorbance and spectral line

• diffractometer using a Cu Kα microfocus X-ray source with λ = 1.5418 Å (Figure 2a). IR spectral measurements The sub-diffraction scattering scanning near-field optical microscope (s-SNOM, neaspec GmbH) uses a metalized atomic force microscopy (AFM) tip. The tip maps the surface relief (topography) by its basic

Fabrication of silver nanoisland films by pulsed laser deposition for surface-enhanced Raman spectroscopy

• Bogusław Budner,
• Mariusz Kuźma,
• Barbara Nasiłowska,
• Bartosz Bartosewicz,
• Malwina Liszewska and
• Bartłomiej J. Jankiewicz

Beilstein J. Nanotechnol. 2019, 10, 882–893, doi:10.3762/bjnano.10.89

• (SNIFs) using PLD on their morphology, optical and SERS enhancement properties. We first describe the PLD fabrication process and the influence of the deposition process parameters on the morphology of the fabricated films determined by SEM and AFM measurements. Then, we present the results of

• nanoisland films per laser pulse The thickness of the silver nanoisland films as a function of the number of applied laser pulses is shown in Figure 1. The plot was made based on AFM measurements of reference Si samples with silver films deposited at room temperature for both fluences of laser radiation used

• probe microscopy images. The thickness of the deposited reference silver layers was measured with an atomic force microscope (AFM, NT-MDT Company) in non-contact mode. To perform AFM measurements, the silver layers were removed in random places on the sample by scratching its surface with a sharp needle

Comparing a porphyrin- and a coumarin-based dye adsorbed on NiO(001)

• Sara Freund,
• Antoine Hinaut,
• Nathalie Marinakis,
• Edwin C. Constable,
• Ernst Meyer,
• Catherine E. Housecroft and
• Thilo Glatzel

Beilstein J. Nanotechnol. 2019, 10, 874–881, doi:10.3762/bjnano.10.88

• (nc-AFM) is used at room temperature (RT) to compare the properties of the two dyes deposited on a NiO(001) single-crystal surface. Under ultrahigh vacuum (UHV) conditions, the adsorption modes of both molecules on the surface of NiO(001) are studied and their charge state upon adsorption are

• surfaces, mandatory for reliable SPM studies, are difficult to prepare because of the hardness of the material and its high reactivity [12][13][14][15][26][27][28][29][30][31][32][33][34]. Figure 2a shows a topographic image measured by nc-AFM of the bare NiO(001) surface that was prepared by in situ

• be determined from the close-up high-resolution nc-AFM topographic image shown in Figure 4b. In this image it can be seen (in green) that the mesh motive is composed of two different pairs of dyes, implying that a unit cell is composed of four molecules. The first pair of molecules has the molecular

Novel reversibly switchable wettability of superhydrophobic–superhydrophilic surfaces induced by charge injection and heating

• Xiangdong Ye,
• Junwen Hou and
• Dongbao Cai

Beilstein J. Nanotechnol. 2019, 10, 840–847, doi:10.3762/bjnano.10.84

• surface-potential characterization. Atomic force microscopy (AFM) was used to characterize the physical morphology (Bruker Dimension Icon, Brook). The water contact angle (CA) of all surfaces was measured using a JC2000C1 contact angle measurements system (Shanghai Zhongchen Digital equipment). At room

• slide was treated under an electric field between the electrodes, and the other half was not treated by the electric field, as shown in Figure 1b. Results and Discussion Coating morphology and wettability The SEM and AFM images of the glass slide before and after the spray coating procedure are shown in

• superhydrophilic but the uncontacted area remained superhydrophobic, as shown in Figure 6. We examined the morphology of the electrode contact area in the coating by SEM and AFM, as shown in Figure 7. There was no obvious morphology change in electrode contact area compared with the electrode non-contact area

Capillary force-induced superlattice variation atop a nanometer-wide graphene flake and its moiré origin studied by STM

• Loji K. Thomas and
• Michael Reichling

Beilstein J. Nanotechnol. 2019, 10, 804–810, doi:10.3762/bjnano.10.80

• way the meniscus can exert a force on a flake on the surface when the nail moves over the surface. In order to explain the capillary forces at a solid–liquid interface pertinent to the STM scenario, we propose a modified model as shown in Figure 3a. In contrast to previous studies in STM [17] and AFM

Self-assembly and wetting properties of gold nanorod–CTAB molecules on HOPG

• Imtiaz Ahmad,
• Floor Derkink,
• Tim Boulogne,
• Pantelis Bampoulis,
• Harold J. W. Zandvliet,
• Hidayat Ullah Khan,
• Rahim Jan and
• E. Stefan Kooij

Beilstein J. Nanotechnol. 2019, 10, 696–705, doi:10.3762/bjnano.10.69

• drying on a nonwetting highly ordered pyrolytic graphite (HOPG) surface have been investigated using scanning electron microscopy (SEM) and atomic force microscopy (AFM). Although SEM did not reveal coverage of CTAB layers, AFM showed not only CTAB assembly, but also the dynamics of the process on the

• superstructures on HOPG substrates using atomic force microscopy (AFM). The assembly of CTAB molecules was investigated at various positions on the substrate. Also, the role of CTAB molecules that changes the wettability of the HOPG terraces is discussed in relation to the previous work [51]. The application of

• the droplet. As such the wettability of the HOPG surface was transformed by establishing a hydrophilic layer underneath the nanorods. In Figure 2 AFM images reveal CTAB stripes oriented in two specific directions, as indicated by the arrows. The angle between these directions is 60° or 120°, as shown

Ultrathin hydrophobic films based on the metal organic framework UiO-66-COOH(Zr)

• Miguel A. Andrés,
• Clemence Sicard,
• Christian Serre,
• Olivier Roubeau and
• Ignacio Gascón

Beilstein J. Nanotechnol. 2019, 10, 654–665, doi:10.3762/bjnano.10.65

• OPD/MOF ultrathin films have been fabricated onto glass, calcium fluoride, quartz crystal microbalance (QCM), Si(100) substrates and mica and characterized using scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), atomic force microscopy (AFM

• investigate the structure of the hydrophobic films obtained, pure ODP LB films and mixed MOF/ODP LB films transferred onto mica were analyzed by AFM (Figure 5). The study of pure ODP monolayers showed that the films present some defects and pinholes, which allow a monolayer thickness between 2 and 3 nm to be

• nm), which leads to higher WCA values and confirms the advantageous interaction of ODP molecules with the surface of MOF sMPs. In fact, the phase images obtained by AFM, which show ODP covering the MOF sMPs (Supporting Information File 1, Figure S10), support this suggested synergy in order to obtain

Review of time-resolved non-contact electrostatic force microscopy techniques with applications to ionic transport measurements

• Aaron Mascaro,
• Yoichi Miyahara,
• Tyler Enright,
• Omur E. Dagdeviren and
• Peter Grütter

Beilstein J. Nanotechnol. 2019, 10, 617–633, doi:10.3762/bjnano.10.62

• period of the cantilever and compare and contrast it with those previously established. Keywords: atomic force microscopy; electrostatic force microscopy; ionic transport; lithium ion batteries; nanotechnology; Introduction Since the inception of the atomic force microscope (AFM) a variety of

• understanding transport properties of real-world, often heterogeneous materials relevant for energy generation and storage. A number of AFM techniques have been developed to study relevant materials including time-resolved EFM to measure photoexcited charge accumulation and charge transfer [6][9][10][11], time

• used frequency-modulated AFM configuration, the resonance frequency of an oscillating cantilever is measured while the probe tip interacts with a surface [24]. The interactions are purely electrostatic – in other words, the tip and sample form a capacitor. The oscillation of the cantilever can

Direct observation of the CVD growth of monolayer MoS₂ using in situ optical spectroscopy

• Claudia Beatriz López-Posadas,
• Yaxu Wei,
• Wanfu Shen,
• Daniel Kahr,
• Michael Hohage and
• Lidong Sun

Beilstein J. Nanotechnol. 2019, 10, 557–564, doi:10.3762/bjnano.10.57

• of the sapphire substrate. This conclusion is based on a thorough ex situ characterization after CVD growth using differential reflectance spectroscopy (DRS), Raman spectroscopy, photoluminescent spectroscopy (PL), optical microscopy (OM), and atomic force microscopy (AFM). Actually, from the first

• substrate reveal that the surfaces at both sides are covered by homogeneous layers, which can only be recognized by the appearance of defects. Figure 1c presents the AFM images measured at the front and back sides of the sapphire substrate confirming that both surfaces are covered by an almost complete

• to the fact that the areas of the surface between the triangular-shaped MoS2 crystals are fully covered by these nanoparticles, no reasonably large surface areas of bare substrate can be found. Consequently, the thickness of the triangular-shaped MoS2 crystals cannot be determined from the AFM height

Quantification and coupling of the electromagnetic and chemical contributions in surface-enhanced Raman scattering

• Yarong Su,
• Yuanzhen Shi,
• Ping Wang,
• Jinglei Du,
• Markus B. Raschke and
• Lin Pang

Beilstein J. Nanotechnol. 2019, 10, 549–556, doi:10.3762/bjnano.10.56

• lithography (IL) and oblique angle deposition (OAD) methods [23]. The Ag substrates with nanostructures are gratings with and without nanogap, which can achieve field enhancements as high as 106. The samples were pre-characterized by AFM (see example of Ag grating with nanogap in inset in Figure 1a, for