Morphology-driven gas sensing by fabricated fractals: A review

• Vishal Kamathe and
• Rupali Nagar

Beilstein J. Nanotechnol. 2021, 12, 1187–1208, doi:10.3762/bjnano.12.88

• permission of AIP Publishing. This content is not subject to CC BY 4.0. Si/WO3 nanowires. (a–d) SEM images of Si/WO3 NWs, (e) HRTEM image of a WO3/SiNW interface, (f) XRD pattern of SiNWs and SiNWs/WO3. Dynamic responses of (g) the composite and (h) pure SiNWs to 0.5–5 ppm NO2 at room temperature

Seebeck coefficient of silicon nanowire forests doped by thermal diffusion

• Shaimaa Elyamny,
• Elisabetta Dimaggio and
• Giovanni Pennelli

Beilstein J. Nanotechnol. 2020, 11, 1707–1713, doi:10.3762/bjnano.11.153

• fabricate large numbers of nanowires with high aspect ratio, perpendicular to a silicon substrate, that is, so-called silicon nanowire (SiNW) forests. The process is very suitable for the large-scale fabrication of nanostructured devices useful for several applications, such as sensing, photovoltaics

• MACE yields very unreliable results at such high doping concentrations. In the case of p+ doping, parameters for a satisfactory fabrication of monocrystalline SiNW forests have been found [17]. However, the reliable fabrication of n+ SiNWs by MACE is still an open issue [19][20]. Hence, it is currently

• ) the direction and the speed of the rotation. During the etch, a temperature-controlled bath allowed to maintain a stable temperature of 18 ± 0.5 °C. The etching time determines the final length of the nanowires. Several SiNW forests with nanowire lengths between 6.5 μm (30 min etching) and 41 μm (3 h

Revealing the local crystallinity of single silicon core–shell nanowires using tip-enhanced Raman spectroscopy

• Marius van den Berg,
• Ardeshir Moeinian,
• Arne Kobald,
• Yu-Ting Chen,
• Anke Horneber,
• Steffen Strehle,
• Alfred J. Meixner and
• Dai Zhang

Beilstein J. Nanotechnol. 2020, 11, 1147–1156, doi:10.3762/bjnano.11.99

• SiNWs are mainly single crystalline. However, in some areas along the nanowire axis defects are present as well (Figure 1a). The diffraction pattern of this part of the SiNW (Figure 1b) shows more than one reflection, which indicates that the structure of the SiNW consists presumably of segments or

• grains with different orientation. Furthermore, catalyst migration along the SiNW backbone was observed in some cases (Figure 1c). Although the SiNWs grown by the VLS mechanism possess are crystalline, the silicon shells deposited onto the nanowires by thermal CVD (here using a temperature of 520 °C) can

• be amorphous [15]. Figure 1d illustrates such a core–shell SiNW with a distinct contrast in core–shell morphology. As it can be seen in Figure 1e and Figure 1f, the core region of the nanowire appears single crystalline and the crystal planes end abruptly at the core–shell interface. The shell region

Features and advantages of flexible silicon nanowires for SERS applications

• Hrvoje Gebavi,
• Vlatko Gašparić,
• Dubravko Risović,
• Nikola Baran,
• Paweł Henryk Albrycht and
• Mile Ivanda

Beilstein J. Nanotechnol. 2019, 10, 725–734, doi:10.3762/bjnano.10.72

• intensity on the VLS process temperature The first step in the synthesis optimization of the horizontally oriented SiNW substrates includes the determination of the optimal VLS synthesis temperature. The color of the substrates ranged from pale yellow to dark brown (Supporting Information File 1, Figure S1

• ). The color change clearly indicates changes of thickness and morphology of the SiNWs induced by the processing temperature (Supporting Information File 1, Figure S2). Roughly, the SiNW diameter increases with VLS process temperature from 50 to 150 nm. Similar values and a linear correlation between

• deposition at 500 °C. After short sputtering times (3 and 5 min), the SiNWs are decorated with irregularly shaped droplets of 20–60 nm diameter (Supporting Information File 1, Figure S6). In the range from 7 to 10 min (Figure 3), the upper SiNW layer is completely covered with Ag, yielding Ag cylinders for

Self-assembly of silicon nanowires studied by advanced transmission electron microscopy

• Marta Agati,
• Guillaume Amiard,
• Vincent Le Borgne,
• Paola Castrucci,
• Richard Dolbec,
• Maurizio De Crescenzi,
• My Alì El Khakani and
• Simona Boninelli

Beilstein J. Nanotechnol. 2017, 8, 440–445, doi:10.3762/bjnano.8.47

• , we focus our study on ICP-produced SiNWs (less than 5% of the whole population) on which a peculiarity exists in the form of a high-contrast nanoparticle at the top. However, conventional 2D TEM imaging would not be able to definitively demonstrate whether the nanoparticle is embedded inside the SiNW

• this paper we focus our study on NWs belonging to the second family. In fact, the reason for our investigation stems from a peculiarity of these SiNWs, namely the presence of a high-contrast nanoparticle on the top (diameter ≈15 nm) corresponding to the SiNW core diameter, as shown in the EFTEM images

• two hours. Nevertheless, from the inspection of Figure 2a alone, it is not possible to discern the nature of another Si nanostructure, indicated by the red arrow in Figure 2a. The presence of a second SiNW appears when the nanostructure is tilted at 35° with respect to the rotation axis, which is

Influence of hydrofluoric acid treatment on electroless deposition of Au clusters

• Rachela G. Milazzo,
• Antonio M. Mio,
• Giuseppe D’Arrigo,
• Emanuele Smecca,
• Alessandra Alberti,
• Gabriele Fisichella,
• Filippo Giannazzo,
• Corrado Spinella and
• Emanuele Rimini

Beilstein J. Nanotechnol. 2017, 8, 183–189, doi:10.3762/bjnano.8.19

• shown quite interesting applications in the fields of Si nanowire (SiNW) catalysis [1][2][3], metal-assisted etching (MAE) [4] or even as electrical contacts in standard miniaturized devices [5]. Their ability to display enhanced surface plasmon resonance (SPR) at optical frequencies makes them

Simple approach for the fabrication of PEDOT-coated Si nanowires

• Mingxuan Zhu,
• Marielle Eyraud,
• Judikael Le Rouzo,
• Nadia Ait Ahmed,
• Florence Boulc’h,
• Claude Alfonso,
• Philippe Knauth and
• François Flory

Beilstein J. Nanotechnol. 2015, 6, 640–650, doi:10.3762/bjnano.6.65

• pulsed electrodeposition technique. N-type Si nanowire (SiNWs) arrays were synthesized using an electroless metal-assisted chemical etching technique. The dependence of the SiNW reflection on the concentration of the AgNO3 solution was identified. A reflection of less than 2% over the entire visible

• electrochemical methods. Since the polymerization reaction is a very fast process with regards to monomer diffusion along the SiNW, the conformal deposition by classical, fixed potential deposition was not favored. Instead, the core–shell heterojunction structure was finally achieved by a pulsed deposition method

• . An extremely large shunt resistance was exhibited and determined to be related to the diffusion conditions occurring during polymerization. Keywords: conductive polymer; core–shell structure; electrodeposition; hybrid material; SiNW; Introduction Silicon nanowires (SiNWs) are a current, active

Review of nanostructured devices for thermoelectric applications

• Giovanni Pennelli

Beilstein J. Nanotechnol. 2014, 5, 1268–1284, doi:10.3762/bjnano.5.141

• . Conversely, a full development of solutions and technologies for the fabrication of contacts is requested for many innovative TE materials. The fabrication of TEGs based on SiNWs must face the challenging fabrication of large scale arrays of SiNW. In this paper, a considerable space has been given to the

Methods for rapid frequency-domain characterization of leakage currents in silicon nanowire-based field-effect transistors

• Tomi Roinila,
• Xiao Yu,
• Jarmo Verho,
• Tie Li,
• Pasi Kallio,
• Matti Vilkko,
• Anran Gao and
• Yuelin Wang

Beilstein J. Nanotechnol. 2014, 5, 964–972, doi:10.3762/bjnano.5.110

• 10.3762/bjnano.5.110 Abstract Silicon nanowire-based field-effect transistors (SiNW FETs) have demonstrated the ability of ultrasensitive detection of a wide range of biological and chemical targets. The detection is based on the variation of the conductance of a nanowire channel, which is caused by the

• frequency characteristics can provide valuable tools in validating the functionality of the used transistor. The measurements can also be an advantage in developing new detection technologies utilizing SiNW FETs. The frequency-domain responses can be measured by using a commercial sine-sweep-based network

• methods is verified by experimental measurements from an n-type SiNW FET. Keywords: admittance spectroscopy; excitation design; frequency characterization; frequency response; silicon nanowire; Introduction Recent development in sensing biochemical molecules has been rapid. Among many sensing

A highly pH-sensitive nanowire field-effect transistor based on silicon on insulator

• Denis E. Presnov,
• Sergey V. Amitonov,
• Pavel A. Krutitskii,
• Valentina V. Kolybasova,
• Igor A. Devyatov,
• Vladimir A. Krupenin and
• Igor I. Soloviev

Beilstein J. Nanotechnol. 2013, 4, 330–335, doi:10.3762/bjnano.4.38

• be useful for biological and medical applications. A demonstration of such a local probe based on a vapour–liquid–solid-method (VLS) grown silicon-nanowire (SiNW) FET was given in [7]. The sensitivity of this bioprobe to pH change near its maximum value of 59 mV per unit pH was reached and the

• SiNW FET fabricated [8] by traditional methods from silicon-on-insulator (SOI) with a pH sensitivity equal to VLS-grown NW FET [7]. The maximum sensitivity in subthreshold mode is estimated to be on the order of 10−3e/. Results and Discussion In Figure 1 a NW FET with a channel length of 5 μm and a

•  2 the transport current of the SiNW FET at different pH values of the buffer solution and at different reference-electrode potentials is shown. One can see that the current level for a transistor in buffer solution at pH 8 and Vref = 0.5 V coincides with the current for a buffer solution at pH 6 and