Out-of-plane polarization induces a picosecond photoresponse in rhombohedral stacked bilayer WSe₂

• Guixian Liu,
• Yufan Wang,
• Zhoujuan Xu,
• Zhouxiaosong Zeng,
• Lanyu Huang,
• Cuihuan Ge and
• Xiao Wang

Beilstein J. Nanotechnol. 2024, 15, 1362–1368, doi:10.3762/bjnano.15.109

• photoelectric detection. Experimental Device fabrication The 2D materials, WSe2 and graphene, were obtained from high-quality bulk crystals using the mechanical exfoliation method. The monolayer WSe2 nanoflakes were exfoliated onto a transparent polydimethylsiloxane (PDMS) film, selected based on optical

• contrast, and characterized by photoluminescence (PL) measurements at room temperature (see Supporting Information File 1, Figure S3). The relative angles between crystalline axes of the top and bottom WSe2 layers were determined by polarization-resolved SHG measurements. The zigzag directions of the two

Determining by Raman spectroscopy the average thickness and N-layer-specific surface coverages of MoS₂ thin films with domains much smaller than the laser spot size

• Felipe Wasem Klein,
• Jean-Roch Huntzinger,
• Vincent Astié,
• Damien Voiry,
• Romain Parret,
• Houssine Makhlouf,
• Sandrine Juillaguet,
• Jean-Manuel Decams,
• Sylvie Contreras,
• Périne Landois,
• Ahmed-Azmi Zahab,
• Jean-Louis Sauvajol and
• Matthieu Paillet

Beilstein J. Nanotechnol. 2024, 15, 279–296, doi:10.3762/bjnano.15.26

• complexity to characterize such samples from the previous Raman criteria with the case of twisted MoS2 bilayers. The identification of the bilayer character of the investigated flakes was unambiguously obtained independently from spectral reflectivity and optical contrast. Figure 5a shows the low-frequency

Graphene removal by water-assisted focused electron-beam-induced etching – unveiling the dose and dwell time impact on the etch profile and topographical changes in SiO₂ substrates

• Aleksandra Szkudlarek,
• Jan M. Michalik,
• Inés Serrano-Esparza,
• Zdeněk Nováček,
• Veronika Novotná,
• Piotr Ozga,
• Czesław Kapusta and
• José María De Teresa

Beilstein J. Nanotechnol. 2024, 15, 190–198, doi:10.3762/bjnano.15.18

• studies: A) optical microscopy, B) scanning electron microscopy (SEM), C) AFM, and D) correlative probe and electron microscopy (CPEM). The optical contrast of graphene placed onto SiO2/Si allows us to easily distinguish between its mono-, bi-, triple, and thicker flakes layers. The values (approx. 2.5 nm

• microscope evaluation allowed us to choose flakes that fitted our requirements the best in terms of lateral sizes and number of graphitic layers (optical contrast abruptly changes from monolayer to the bilayer, triple-layer, or HOPG) [37]. The same substrates of separate studies of topographical changes

Revealing local structural properties of an atomically thin MoSe₂ surface using optical microscopy

• Lin Pan,
• Peng Miao,
• Anke Horneber,
• Alfred J. Meixner,
• Pierre-Michel Adam and
• Dai Zhang

Beilstein J. Nanotechnol. 2022, 13, 572–581, doi:10.3762/bjnano.13.49

• the optical contrast, one can estimate that the thickness of the more transparent areas of the MoSe2 flake is smaller than that of other regions. To visualize the CuPc molecule distribution on the MoSe2 flake, atomic force microscopy (AFM) was used, and the results are shown in Figure 1b. The insets

Light–matter interactions in two-dimensional layered WSe₂ for gauging evolution of phonon dynamics

• Avra S. Bandyopadhyay,
• Chandan Biswas and
• Anupama B. Kaul

Beilstein J. Nanotechnol. 2020, 11, 782–797, doi:10.3762/bjnano.11.63

• WSe2 Mechanically exfoliated high-quality WSe2 nanomembranes were observed under an optical microscope through optical contrast differences on the SiO2/Si substrates. The optical image of monolayer (1L), ML, and bulk WSe2 is shown in Figure 1a. Monolayer TMDCs such as WSe2 have a ground state structure

Nitrogen-vacancy centers in diamond for nanoscale magnetic resonance imaging applications

• Alberto Boretti,
• Lorenzo Rosa,
• Jonathan Blackledge and
• Stefania Castelletto

Beilstein J. Nanotechnol. 2019, 10, 2128–2151, doi:10.3762/bjnano.10.207

Optimization of the optical coupling in nanowire-based integrated photonic platforms by FDTD simulation

• Nan Guan,
• Andrey Babichev,
• Martin Foldyna,
• Dmitry Denisov,
• François H. Julien and
• Maria Tchernycheva

Beilstein J. Nanotechnol. 2018, 9, 2248–2254, doi:10.3762/bjnano.9.209

• small optical contrast with GaN. The length of the NW LED and the detector is 10 µm, and the waveguide between them is 31 µm long. The waveguide width is varied in this work to optimize the optical coupling. Both two-dimensional (2D) and three-dimensional (3D) optical models were applied using

The nanofluidic confinement apparatus: studying confinement-dependent nanoparticle behavior and diffusion

• Stefan Fringes,
• Felix Holzner and
• Armin W. Knoll

Beilstein J. Nanotechnol. 2018, 9, 301–310, doi:10.3762/bjnano.9.30

• surface. We first determine the height of the particles as a function of gap distance by means of their varying optical contrast. Next we determine the lateral diffusion for a range of fixed gap distances. The gap-dependent measurement allows us not only to measure the decreasing diffusion coefficients

Optical contrast and refractive index of natural van der Waals heterostructure nanosheets of franckeite

• Patricia Gant,
• Foad Ghasemi,
• David Maeso,
• Carmen Munuera,
• Elena López-Elvira,
• Riccardo Frisenda,
• David Pérez De Lara,
• Gabino Rubio-Bollinger,
• Mar Garcia-Hernandez and
• Andres Castellanos-Gomez

Beilstein J. Nanotechnol. 2017, 8, 2357–2362, doi:10.3762/bjnano.8.235

• -illumination-mode optical microscopy images provides a rapid method to estimate the thickness of the exfoliated flakes at first glance. A quantitative analysis of the optical contrast spectra by means of micro-reflectance allows one to determine the refractive index of franckeite over a broad range of the

• visible spectrum through a fit of the acquired spectra to a model based on the Fresnel law. Keywords: complex refractive index; franckeite; optical contrast; optical identification; van der Waals heterostructure; Introduction Mechanical exfoliation is a very powerful technique to produce a large variety

• material is isolated one of the most urgent things is to establish a correlation between the thicknesses of the exfoliated flakes and their optical contrast (in order to be used as a calibration guide to identify ultrathin flakes optically) and to determine the optimal substrates to identify ultrathin

Optical techniques for cervical neoplasia detection

• Tatiana Novikova

Beilstein J. Nanotechnol. 2017, 8, 1844–1862, doi:10.3762/bjnano.8.186

• optical contrast between isolated gold particles and agglomerated gold particles in tumor tissue in both confocal reflectance and confocal fluorescence images of cervical tissue specimens [89]. In recent years many research groups explored the potential of using quantum dots (QDs) as inorganic

In-situ monitoring by Raman spectroscopy of the thermal doping of graphene and MoS₂ in O₂-controlled atmosphere

• Aurora Piazza,
• Filippo Giannazzo,
• Gianpiero Buscarino,
• Gabriele Fisichella,
• Antonino La Magna,
• Fabrizio Roccaforte,
• Marco Cannas,
• Franco Mario Gelardi and
• Simonpietro Agnello

Beilstein J. Nanotechnol. 2017, 8, 418–424, doi:10.3762/bjnano.8.44

• temperatures. As shown in Figure 6, we noticed a decrease of optical contrast in optical microscope measurements between the center of the MoS2 flakes and their edges, the latter appearing darker. To go deeper into this aspect we carried out AFM measurements and, as shown in Figure 6, we found that the edges

An ellipsometric approach towards the description of inhomogeneous polymer-based Langmuir layers

• Falko O. Rottke,
• Burkhard Schulz,
• Klaus Richau,
• Karl Kratz and
• Andreas Lendlein

Beilstein J. Nanotechnol. 2016, 7, 1156–1165, doi:10.3762/bjnano.7.107

• displayed two or more times within one ellipsometric map. Moreover, layers at the air–water interface are well within the ultrathin film limit and, as it has been ruled out earlier, this hampers modeling. Lastly, the use of solid substrates increases the optical contrast in many cases. Nevertheless, in situ

Effect of contaminations and surface preparation on the work function of single layer MoS₂

• Oliver Ochedowski,
• Kolyo Marinov,
• Nils Scheuschner,
• Artur Poloczek,
• Benedict Kleine Bussmann,
• Janina Maultzsch and
• Marika Schleberger

Beilstein J. Nanotechnol. 2014, 5, 291–297, doi:10.3762/bjnano.5.32

• 40 nm measured using AFM. Immediately after etching, the MoS2 was exfoliated by mechanical cleavage [32]. Single layer MoS2 flakes were located by using their optical contrast and verified using Raman spectroscopy [33][34]. For Raman point measurements and mappings, a Renishaw InVia Raman

Micro- and nanoscale electrical characterization of large-area graphene transferred to functional substrates

• Gabriele Fisichella,
• Salvatore Di Franco,
• Patrick Fiorenza,
• Raffaella Lo Nigro,
• Fabrizio Roccaforte,
• Cristina Tudisco,
• Guido G. Condorelli,
• Nicolò Piluso,
• Noemi Spartà,
• Stella Lo Verso,
• Corrado Accardi,
• Cristina Tringali,
• Sebastiano Ravesi and
• Filippo Giannazzo

Beilstein J. Nanotechnol. 2013, 4, 234–242, doi:10.3762/bjnano.4.24

• following. Graphene transfer onto silicon dioxide The graphene membrane was transferred from the Cu foil onto a Si wafer coated by 300 nm thick thermally grown SiO2. This oxide thickness was properly selected because it ensures the best optical contrast between bare SiO2 regions and regions coated by the

• . Due to the good optical contrast between the graphene-coated and bare SiO2 areas, a homogenous graphene membrane, free from macroscopic cracks, can be observed. Higher resolution morphological analyses of the graphene layer onto SiO2 were carried out by tapping mode AFM. Two representative AFM images

Characterization and properties of micro- and nanowires of controlled size, composition, and geometry fabricated by electrodeposition and ion-track technology

• Maria Eugenia Toimil-Molares

Beilstein J. Nanotechnol. 2012, 3, 860–883, doi:10.3762/bjnano.3.97

• the wire can, e.g., be used to incorporate electrical functionality, optical contrast, and/or desired surface chemistry [104]. Segmented Au/Pt nanowires were demonstrated to move autonomously when placed in a hydrogen peroxide solution [105]. Also, biofunctionalized nanowire bar codes were used for ss

Investigation on structural, thermal, optical and sensing properties of meta-stable hexagonal MoO₃ nanocrystals of one dimensional structure

• Angamuthuraj Chithambararaj and
• Arumugam Chandra Bose

Beilstein J. Nanotechnol. 2011, 2, 585–592, doi:10.3762/bjnano.2.62

• reactive catalysts, high optical contrast electrochromic devices and cathodic electrodes for lithium batteries, due to their unique structural, optical and electrical properties [2][3][4][5]. Several synthetic techniques have been developed for controlled synthesis of nanocrystalline MoO3 materials [6][7