High-responsivity hybrid α-Ag₂S/Si photodetector prepared by pulsed laser ablation in liquid

• Raid A. Ismail,
• Hanan A. Rawdhan and
• Duha S. Ahmed

Beilstein J. Nanotechnol. 2020, 11, 1596–1607, doi:10.3762/bjnano.11.142

• , a SiO2 thin film was grown on the silicon substrate before Ag2S deposition through rapid thermal oxidation (RTO) at a temperature of 950 °C for 25 s, and then HF etchant was used to open a Si window on SiO2. The experimental details regarding the RTO process are presented elsewhere [20]. To

Wafer-level integration of self-aligned high aspect ratio silicon 3D structures using the MACE method with Au, Pd, Pt, Cu, and Ir

• Mathias Franz,
• Romy Junghans,
• Paul Schmitt,
• Adriana Szeghalmi and
• Stefan E. Schulz

Beilstein J. Nanotechnol. 2020, 11, 1439–1449, doi:10.3762/bjnano.11.128

• will be oxidised to the intermediate state SiO2, which is etched by HF. In this case no H2 is formed. Due to the high number of involved holes, this etching mechanism is strongly correlated to the interface of silicon and the noble metal. This regime will lead to a straight silicon etching profile

Impact of fluorination on interface energetics and growth of pentacene on Ag(111)

• Qi Wang,
• Meng-Ting Chen,
• Antoni Franco-Cañellas,
• Bin Shen,
• Thomas Geiger,
• Holger F. Bettinger,
• Frank Schreiber,
• Ingo Salzmann,
• Alexander Gerlach and
• Steffen Duhm

Beilstein J. Nanotechnol. 2020, 11, 1361–1370, doi:10.3762/bjnano.11.120

• [40][41][42][43][44]. However, in thin films comprised of molecules in a standing orientation on SiO2 (long molecular axis perpendicular to the substrate), the IE of PEN decreases to 4.90 eV and the IE of PFP increases to 6.65 eV [45]. The opposite trend of the orientation dependency of the IEs has

Effect of localized helium ion irradiation on the performance of synthetic monolayer MoS₂ field-effect transistors

• Jakub Jadwiszczak,
• Pierce Maguire,
• Conor P. Cullen,
• Georg S. Duesberg and
• Hongzhou Zhang

Beilstein J. Nanotechnol. 2020, 11, 1329–1335, doi:10.3762/bjnano.11.117

• synthesized using a CVD microreactor method, described in detail in [33], directly on 285 nm SiO2/Si substrates, which also served as the back-gate in the FET configuration. MoS2 flakes were contacted with electrodes using standard electron beam lithography on polymethyl methacrylate (PMMA) resist, followed

• helium ion microscope chamber (after initial electrical testing to confirm functionality) and were irradiated with the stage tilt angle set to 0°. At this angle of incidence, the helium ion beam ought to produce sulfur vacancies chiefly in the bottom sulfuric layer of the SiO2-supported MoS2 flake [34

• atomic vacancy yield per each delivered ion as a function of target penetration depth on the 35 nm-Au/5 nm-Ti/0.7 nm-MoS2/285 nm-SiO2 stack [41]. As evident from Figure 3d, the sulfur sputtering yield at the Ti–MoS2 interface is very close to that of unencapsulated MoS2 [15], indicating notable damage to

Ultrasensitive detection of cadmium ions using a microcantilever-based piezoresistive sensor for groundwater

• Dinesh Rotake,
• Anand Darji and
• Nitin Kale

Beilstein J. Nanotechnol. 2020, 11, 1242–1253, doi:10.3762/bjnano.11.108

• . [28], but it is not suitable for other high-temperature sputtering processes. Microcantilevers based on SiO2 have been manufactured by Tang et al. [29] to enhance the sensitivity of cantilever sensors. Many authors use optical setups for microcantilevers. However, an optical output has several

• . It was calibrated using atomic force microscopy (AFM) [40]. The process begins with thermal oxidation of Si at 1000 °C using an oxidation furnace to obtain a thermally grown SiO2 layer followed by masking and etching to get the desired pattern. The polysilicon is deposited in a low-pressure chemical

• vapor deposition (LPCVD) furnace at 630 °C and boron doping (1018 per cm3) is carried out using ion implantation at 35 keV. The upper SiO2 layer is formed by re-oxidizing the polysilicon in an oxidation furnace [40]. The stiffness (k) of the fabricated piezoresistive sensor measured using AFM is 131–146

3D superconducting hollow nanowires with tailored diameters grown by focused He⁺ beam direct writing

• Rosa Córdoba,
• Alfonso Ibarra,
• Dominique Mailly,
• Isabel Guillamón,
• Hermann Suderow and
• José María De Teresa

Beilstein J. Nanotechnol. 2020, 11, 1198–1206, doi:10.3762/bjnano.11.104

• transport study using the typical four-point-probe configuration has been performed. Following the procedure described in [17], first 3D NWs were placed flat on the SiO2 layer of a Si/SiO2 substrate by means of a nano-manipulator. Then, four Pt FIBID contacts were grown to connect the NWs to pre-patterned

• -patterned Ti pads (150 nm in thickness) to prevent charge effects on the insulator layer (250 nm thick of SiO2) thermally grown on a silicon wafer [23]. These chips were fabricated following a routine recipe for UV optical lithography using a lift-off method. For the electron tomography and (HR)STEM

Nonadiabatic superconductivity in a Li-intercalated hexagonal boron nitride bilayer

• Kamila A. Szewczyk,
• Izabela A. Domagalska,
• Artur P. Durajski and
• Radosław Szczęśniak

Beilstein J. Nanotechnol. 2020, 11, 1178–1189, doi:10.3762/bjnano.11.102

• ][17][18][19], Ru [20][21], Pt [22][23], SiC [24][25][26], and SiO2 [27][28][29]. Unfortunately, the obtained experimental data showed that the incompatible crystalline structure of the above materials leads to significant suppression of the carrier mobility of graphene [13][30]. It is now assumed that

• result is radically different from the data obtained for graphene/SiO2 [33]. In addition, hBN monolayers exhibit a high temperature stability, a low dielectric constant (ε = 3–4), and a high thermal conductivity [34]. The band gap of hBN is about 5.9 eV [35]. Furthermore, which is also important, hBN is

Scanning tunneling microscopy and spectroscopy of rubrene on clean and graphene-covered metal surfaces

• Karl Rothe,
• Alexander Mehler,
• Nicolas Néel and
• Jörg Kröger

Beilstein J. Nanotechnol. 2020, 11, 1157–1167, doi:10.3762/bjnano.11.100

• ] and hexagonal boron nitride (h-BN) [3] have been studied in detail. In contrast, vibrational spectroscopy at the single-molecule level is scarce. Scanning tunneling spectroscopy (STS) of vibronic levels of 1,3,5-tris(2,2-dicyanovinyl)benzene on graphene-covered h-BN on SiO2 [4], of cobalt

• phthalocyanine molecules on graphene-covered SiO2/Si samples [5] as well as on h-BN-covered Ir(111) [6], of conjugated oligohenylenes on h-BN-covered Cu(111) [7], of manganese phthalocyanine on h-BN-covered Rh(111) [8], and of 5,10,15,20-tetraphenylbisbenz[5,6]indendo[1,2,3-cd:1′,2′,3′-lm]perylene on graphene

Photothermally active nanoparticles as a promising tool for eliminating bacteria and biofilms

• Mykola Borzenkov,
• Piersandro Pallavicini,
• Angelo Taglietti,
• Laura D’Alfonso,
• Maddalena Collini and
• Giuseppe Chirico

Beilstein J. Nanotechnol. 2020, 11, 1134–1146, doi:10.3762/bjnano.11.98

• of a NaYF4:Mn/Yb/Er@photosensitizer doped with SiO2 This allowed for the integration of photodynamic and photothermic therapy to improve the treatment against multidrug-resistant bacteria [82]. It was demonstrated that such nanodevices exhibited superior antibacterial activity towards drug-resistant

Measurement of electrostatic tip–sample interactions by time-domain Kelvin probe force microscopy

• Christian Ritz,
• Tino Wagner and
• Andreas Stemmer

Beilstein J. Nanotechnol. 2020, 11, 911–921, doi:10.3762/bjnano.11.76

• exfoliation from bulk graphite [32][33] and deposited on a piece of Si/SiO2. Measurements were carried out using an Asylum Research Cypher AFM connected to a Zurich Instruments HF2 lock-in amplifier. Figure 3 shows the results of the open-loop controller. During the FM-AFM measurement the tip voltage was

• the electrostatic potential above the graphene flake and the SiO2 substrate. The patterns observable on the graphene flake are most likely caused by water droplets, which have formed due to the ambient conditions [34][35]. Small changes in the patterns were observed between two different scans

• surface potential above the graphene flake is smaller than that above the SiO2 substrate. The residual of the state observer is shown in Figure 3i. This signal contains the amount of the frequency shift that could not be attributed to any surface property, for example the estimated measurement noise. In

Integrated photonics multi-waveguide devices for optical trapping and Raman spectroscopy: design, fabrication and performance demonstration

• Gyllion B. Loozen,
• Arnica Karuna,
• Mohammad M. R. Fanood,
• Erik Schreuder and
• Jacob Caro

Beilstein J. Nanotechnol. 2020, 11, 829–842, doi:10.3762/bjnano.11.68

• central region of the microbath. This implies that the beams should be narrow and have a low divergence. To realize this, we chose the single-stripe waveguide of our TripleX waveguiding platform [9]. This is a rectangular Si3N4 ridge waveguide embedded in SiO2 cladding. The TripleX platform offers high

• have control structures. The first fabrication step is the wet thermal oxidation of Si at 1150 °C to obtain an 8 µm thick layer of SiO2 (Figure 5a). This layer serves as the bottom cladding for the excitation waveguides. Its thickness is chosen such that the 785 nm light within the excitation

• away from the edge. In the next step, a 3 µm thick layer of SiO2 is deposited using LPCVD (Figure 5e). This layer acts as an upper cladding of the excitation waveguides and separates these from the waveguiding layer that follows. For simplicity, we do not show the surface topography resulting after

Templating effect of single-layer graphene supported by an insulating substrate on the molecular orientation of lead phthalocyanine

• K. Priya Madhuri,
• Abhay A. Sagade,
• Pralay K. Santra and
• Neena S. John

Beilstein J. Nanotechnol. 2020, 11, 814–820, doi:10.3762/bjnano.11.66

• Technology, Kattankulathur 603 203, Tamil Nadu, India 10.3762/bjnano.11.66 Abstract The influence of single-layer graphene on top of a SiO2/Si surface on the orientation of nonplanar lead phthalocyanine (PbPc) molecules is studied using two-dimensional grazing incidence X-ray diffraction. The studies

• oriented pyrolytic graphite (HOPG) or SiO2, it has been reported that CuPc attains different orientations resulting in substantial differences in donor–acceptor energy level alignment at the interface. Thus, ordering and orientation of these molecules significantly affect charge carrier injection and

• ) substrate [24]. It will be interesting to explore the molecular orientation of nonplanar PbPc on single-layer graphene supported on a substrate. In this study, we have investigated the molecular orientation of a PbPc film deposited on chemical vapor deposition (CVD)-grown graphene transferred onto a SiO2/Si

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

• , ML and bulk samples, were mechanically exfoliated on top of SiO2/Si substrates (SiO2 thickness = 270 nm) using the scotch tape method [1][30][31]. The mechanical exfoliation process used in this study is similar to the one reported in our earlier work [30]. Prior to the exfoliation procedure, the

• 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

• sapphire substrate is used compared to SiO2/Si substrates [24]. As the SiO2/Si susbstrate and the preparation method (mechanical exfoliation) remained the same for 1L and bulk WSe2 used in our study, this may be the reason why the intensity of the Raman mode remained unchanged even in bulk WSe2. Moreover

Hexagonal boron nitride: a review of the emerging material platform for single-photon sources and the spin–photon interface

• Stefania Castelletto,
• Faraz A. Inam,
• Shin-ichiro Sato and
• Alberto Boretti

Beilstein J. Nanotechnol. 2020, 11, 740–769, doi:10.3762/bjnano.11.61

• plasma etching and subsequent annealing in Ar, yielding a considerable increase in the concentration of emitters in h-BN [122]; laser irradiation [123] even if the formation origin, in this case, is unclear; substrate strain-induced where a 20 nm-thick h-BN film grown via CVD is transferred into SiO2

A novel dry-blending method to reduce the coefficient of thermal expansion of polymer templates for OTFT electrodes

• Xiangdong Ye,
• Bo Tian,
• Yuxuan Guo,
• Fan Fan and
• Anjiang Cai

Beilstein J. Nanotechnol. 2020, 11, 671–677, doi:10.3762/bjnano.11.53

• thermal expansion (CTE) of the polymer template is much higher than the CTE of the dielectric layer. Here, a novel dry-blending method is described in which SiO2 nanoparticles are filled into a grooved silicon template, followed by permeation of polydimethylsiloxane (PDMS) into the SiO2 nanoparticle gaps

• . The SiO2 nanoparticles in the groove are extracted by curing and peeling off PDMS to prepare a PDMS/SiO2 composite template with a nanoparticle content of 83.8 wt %. The composite template has a CTE of 96 ppm/°C, which is a reduction by 69.23% compared with the original PDMS template. Finally, we

• achieved the alignment of OTFT electrodes using the composite template. Keywords: coefficient of thermal expansion; dry blending; organic thin-film transistors (OTFTs); OTFT electrodes; PDMS/SiO2 composite template; Introduction Organic thin-film transistors (OTFTs) provide a platform to construct next

Exfoliation in a low boiling point solvent and electrochemical applications of MoO₃

• Matangi Sricharan,
• Bikesh Gupta,
• Sreejesh Moolayadukkam and
• H. S. S. Ramakrishna Matte

Beilstein J. Nanotechnol. 2020, 11, 662–670, doi:10.3762/bjnano.11.52

• (AFM; Agilent 5500). Samples for FESEM and AFM were prepared by dripping 10 µL of MoO3 dispersion (diluted 100 times) onto a Si/SiO2 (300 nm) substrate while samples for TEM were prepared by dripping 10 µL of the diluted dispersion on a 300 mesh lacey carbon grid. Raman spectra (Horiba LABRam HR) of

Multilayer capsules made of weak polyelectrolytes: a review on the preparation, functionalization and applications in drug delivery

• Varsha Sharma and
• Anandhakumar Sundaramurthy

Beilstein J. Nanotechnol. 2020, 11, 508–532, doi:10.3762/bjnano.11.41

• template removal, which also affected the shell structure limiting their biological applications [25]. The use of silicon oxide (SiO2) templates is quite common, however, dissolution using hazardous hydrofluoric acid (HF) limits its application. It is mostly used with strong PE systems but has also been

• extended to weak PE assemblies [26]. The dissolution of a SiO2 core in a poly(allylamine hydrochloride) (PAH)/poly(methacrylic acid) (PMA) assembly with ammonium fluoride (NH4F) at a suitable pH contributed to both multilayer stability and colloidal stability as shown in the AFM images in Figure 2a–d [24

• phenol formaldehyde resin (MPR) multilayered hollow nanocapsules were obtained using SiO2 as a sacrificial template [47]. Notably, the excess charges induced into the multilayer films by the deprotonation of carboxylic acid groups at pH > 5 played a key role in destabilizing the hydrogen bonded films [48

Evolution of Ag nanostructures created from thin films: UV–vis absorption and its theoretical predictions

• Robert Kozioł,
• Marcin Łapiński,
• Paweł Syty,
• Damian Koszelow,
• Wojciech Sadowski,
• Józef E. Sienkiewicz and
• Barbara Kościelska

Beilstein J. Nanotechnol. 2020, 11, 494–507, doi:10.3762/bjnano.11.40

• keep this error reasonably small. Also, the thin SiO2 layer has been neglected, because it is thinner that the computational grid and cannot be correctly modelled. We have performed complementary short simulations with a very limited sample size and with a 2 nm grid, which showed that errors coming

• from the SiO2 layer do not exceed 2%. A light source of 460 nm wavelength has been used, propagating along the y axis direction. Two independent simulations were performed, one with a transverse-electric (TE) polarized beam and the second one with a transverse-magnetic (TM) polarized beam. These

• ), they consist of Ag. Detailed EDS analysis of a cross section of a nanoisland is presented in Figure 8c. As can be seen, a thin layer of natural SiO2, about 2 nm thick, is present on the silicon surface. Interestingly, there is no oxide layer around the Ag nanostructures. The quality of the

Formation of nanoripples on ZnO flat substrates and nanorods by gas cluster ion bombardment

• Xiaomei Zeng,
• Vasiliy Pelenovich,
• Bin Xing,
• Rakhim Rakhimov,
• Wenbin Zuo,
• Alexander Tolstogouzov,
• Chuansheng Liu,
• Dejun Fu and
• Xiangheng Xiao

Beilstein J. Nanotechnol. 2020, 11, 383–390, doi:10.3762/bjnano.11.29

• substrates have been employed, such as Si wafers, bulk Au samples or SiO2 films. There are very few papers on the ripple formation on the surface of confined nanostructures both by monoatomic and cluster ion irradiation. Therefore, in this research we study features of nanoripple formation on the facets of

• developed and wavelength and height of the ripples calculated from the bottom drift line surface increase (Figure 4b and Table 1). This behavior is in agreement with data obtained for SiO2 films and gold surfaces bombarded with Ar clusters [19][22]. The process of ripple formation is triggered by the

An advanced structural characterization of templated meso-macroporous carbon monoliths by small- and wide-angle scattering techniques

• Felix M. Badaczewski,
• Marc O. Loeh,
• Torben Pfaff,
• Dirk Wallacher,
• Daniel Clemens and
• Bernd M. Smarsly

Beilstein J. Nanotechnol. 2020, 11, 310–322, doi:10.3762/bjnano.11.23

• , prepared by hard-templating of meso-macroporous SiO2 monoliths, to the corresponding nanoscale polyaromatic microstructure using two different carbon precursors wthat generally exhibit markedly different carbonization properties, i.e., a graphitizable pitch and a non-graphitizable resin. The micro- and

• meso-macroporous SiO2 monoliths, and to a linkage of these parameters to the corresponding nanoscale polyaromatic microstructure. Usually, temperature treatment at elevated temperatures needs to be applied to carbonize molecular organic substances, but the commonly applied temperatures of 800–3000 °C

• create meso- or macropores into the carbon system templating approaches have become a routine strategy. One prominent attempt is hard-templating based on silica monoliths with a bimodal pore size distribution (meso- and macropores) and a hierarchical pore network [35][36][37][38]. The SiO2 solid is

Nanosecond resistive switching in Ag/AgI/PtIr nanojunctions

• Botond Sánta,
• Dániel Molnár,
• Patrick Haiber,
• Agnes Gubicza,
• Edit Szilágyi,
• Zsolt Zolnai,
• András Halbritter and
• Miklós Csontos

Beilstein J. Nanotechnol. 2020, 11, 92–100, doi:10.3762/bjnano.11.9

• following the method of Kumar and co-workers [36]. The Ag films were evaporated on standard Si/SiO2 wafers using a 12 nm thick Ti sticking layer. The structural characterization of the thin film samples was carried out by Rutherford backscattering spectrometry (RBS) using an ion beam of 3500 keV 4He

• structure (top to bottom) of 200 nm AgI, 22.5 nm Ag3I and 43 nm Ag after iodine exposure on the Ti/SiO2/Si substrate. Nanometer-scale Ag/AgI/PtIr nanojunctions were created by bringing the PtIr tip into direct contact with the thin-film surface while a constant bias voltage of 100 mV was applied on the

The effect of heat treatment on the morphology and mobility of Au nanoparticles

• Sven Oras,
• Sergei Vlassov,
• Simon Vigonski,
• Boris Polyakov,
• Mikk Antsov,
• Vahur Zadin,
• Rünno Lõhmus and
• Karine Mougin

Beilstein J. Nanotechnol. 2020, 11, 61–67, doi:10.3762/bjnano.11.6

• particles became immovable again. This effect was attributed to the diffusion of Au into the Si substrate and to the growth of the SiO2 layer. Keywords: annealing; atomic force microscopy (AFM); Au nanoparticles; manipulation; melting; nanotribology; Introduction Gold is one of the most prominent

• transmission electron microscopy (TEM). Characterization The morphology of the NPs annealed at different temperatures was studied by TEM (ARM200, JEOL). A null ellipsometer (Multiskop, Optrel, Germany) equipped with a 532 nm Nd:YAG laser was used for measuring the thickness of the SiO2 layers. AFM setup The

• interstitial diffusion [27]. The process is highly temperature-dependent, and diffusion at 800 °C is four orders of magnitude faster than at 400 °C (see Table 7 in Fisher [28]). Another reason may be the temperature-sensitive growth of the SiO2 layer [29], which escalates rapidly above 600 °C, as can be seen

Label-free highly sensitive probe detection with novel hierarchical SERS substrates fabricated by nanoindentation and chemical reaction methods

• Jingran Zhang,
• Tianqi Jia,
• Yongda Yan,
• Li Wang,
• Peng Miao,
• Yimin Han,
• Xinming Zhang,
• Guangfeng Shi,
• Yanquan Geng,
• Zhankun Weng,
• Daniel Laipple and
• Zuobin Wang

Beilstein J. Nanotechnol. 2019, 10, 2483–2496, doi:10.3762/bjnano.10.239

• detected using the AuNPs/PMMA film SERS substrates. Zhang et al. [12] fabricated core–shell structures comprised of SiO2 and gold with a sub-10 nm shell thickness by adding HAuCl4 and the reducing agent K2CO3 on the SiO2 surface and found that the SERS enhancement becomes weaker with increasing shell

Coating of upconversion nanoparticles with silica nanoshells of 5–250 nm thickness

• Cynthia Kembuan,
• Maysoon Saleh,
• Bastian Rühle,
• Ute Resch-Genger and
• Christina Graf

Beilstein J. Nanotechnol. 2019, 10, 2410–2421, doi:10.3762/bjnano.10.231

• of the UCNP@SiO2 core–shell particles was obtained from these STEM images, and the corresponding hydrodynamic diameters were measured by dynamic light scattering (DLS, see below in Table 1). Although large, core-free silica particles can easily be obtained by Stöber-like growth processes [28], and

• for the further steps of the silica shell growth is discussed. For a second silica shell with the thickness t2, the volume of TEOS (VT) was calculated for a given mass mUCNP of uncoated UCNP cores with diameter dU according to Equation 1 assuming 100% conversion of TEOS to SiO2 and the absence of any

• secondary nucleation: where t1 is the thickness of the first silica shell, ρS is the density of colloidal silica (2 g/cm3), ρU is the density of the UCNP cores (4.21 g/cm3), MT is the molar mass of TEOS (208.32 g/mol), MS is the molar mass of SiO2 (60.08 g/mol) and ρT is the density of TEOS (0.94 g/cm3

Liquid crystal tunable claddings for polymer integrated optical waveguides

• José M. Otón,
• Manuel Caño-García,
• Fernando Gordo,
• Eva Otón,
• Morten A. Geday and
• Xabier Quintana

Beilstein J. Nanotechnol. 2019, 10, 2163–2170, doi:10.3762/bjnano.10.209

• integrating electronic and photonic components in the same circuit. The main drawback for silicon waveguides to become tunable devices is the big difference in refractive indices between the core (Si, n > 3.0) and the cladding (SiO2, n < 1.50). This difference confines the propagating wave inside the core

• coated with approx. 4µm SiO2 (n ≈ 1.470) to avoid light leakage through the silicon for its refractive index is higher than the indices of the polymer. The LC layer thickness was 6 µm, controlled using a frame of Mylar spacers between the chip and the glass cover. The inner glass plate surfaces were

• . The substrate is SiO2 on an Si wafer; the LC cladding is not deposited yet. Upper inset: MMI configured for a 100:0 coupling. Lower inset: outputs (about 95:5). An MMI with inorganic Si3N4 core and high-birefringence LC cladding does not show variations in characteristic length, unless the waveguide