Properties of graphene deposited on GaN nanowires: influence of nanowire roughness, self-induced nanogating and defects

• Jakub Kierdaszuk,
• Piotr Kaźmierczak,
• Justyna Grzonka,
• Aleksandra Krajewska,
• Aleksandra Przewłoka,
• Wawrzyniec Kaszub,
• Zbigniew R. Zytkiewicz,
• Marta Sobanska,
• Maria Kamińska,
• Andrzej Wysmołek and
• Aneta Drabińska

Beilstein J. Nanotechnol. 2021, 12, 566–577, doi:10.3762/bjnano.12.47

• interesting experimental material to study [1][2][3]. Importantly, it is a promising material for new kinds of low-dimensional transistors, gas sensors, ultra-capacitors, electrodes for solar cells, and for van der Waals heterostructures. In order to construct these devices, an interaction between graphene

• mobility and, consequently, graphene conductivity. On the other hand, chemical functionalization of graphene may improve the sensitivity of graphene-based sensors [6]. Therefore, the control of density and types of defects in graphene might be a new way to prepare efficient molecular sensors. Systems

Determining amplitude and tilt of a lateral force microscopy sensor

• Oliver Gretz,
• Alfred J. Weymouth,
• Thomas Holzmann,
• Korbinian Pürckhauer and
• Franz J. Giessibl

Beilstein J. Nanotechnol. 2021, 12, 517–524, doi:10.3762/bjnano.12.42

• frequency-modulation atomic force microscopy, the tip oscillates parallel to the surface. Existing amplitude calibration methods are not applicable for mechanically excited LFM sensors at low temperature. Moreover, a slight angular offset of the oscillation direction (tilt) has a significant influence on

• energy to excite the sensor is very small and mechanical vibrations can dominate the excitation [19]. For low-temperature LFM, the lattice of the substrate can be used to calibrate the amplitude if the periodicity of the lateral features is known [20]. For electrically excited piezoelectric-based sensors

Simulation of gas sensing with a triboelectric nanogenerator

• Kaiqin Zhao,
• Hua Gan,
• Huan Li,
• Ziyu Liu and
• Zhiyuan Zhu

Beilstein J. Nanotechnol. 2021, 12, 507–516, doi:10.3762/bjnano.12.41

• can also be used as sensors [22]. TENGs, originally proposed by Prof. Zhongling Wang [23], are microgenerators that convert mechanical energy into electrical energy based on the triboelectric effect [24]. In most TENG simulations, a triboelectric polymer material is in direct contact with an electrode

• [40]. It is attractive that, in addition to providing power for electronic devices, TENGs can also be used as self-powered sensors for pressure, vibration, speed, chemicals, and body motion. Regarding leaks in gas pipelines or harmful gases in underground coal mines, it is necessary to detect the

• presence of a specific gas or the content of gas in ambient air. Therefore, gas sensors are usually indispensable in safety systems. Ordinary sensors need to be charged externally, and once the power is used up, the gas sensor loses its function. TENGs generate electricity that can be used for developing

Interface interaction of transition metal phthalocyanines with strontium titanate (100)

• Reimer Karstens,
• Thomas Chassé and
• Heiko Peisert

Beilstein J. Nanotechnol. 2021, 12, 485–496, doi:10.3762/bjnano.12.39

• Reimer Karstens Thomas Chasse Heiko Peisert Institute of Physical and Theoretical Chemistry, University of Tübingen, Auf der Morgenstelle 18, 72076 Tübingen, Germany Center for Light–Matter Interaction, Sensors & Analytics (LISA+) at the University of Tübingen, Auf der Morgenstelle 18, 72076

• cells, field-effect transistors (FETs), and sensors [1][2]. Possibly, one of the most extensively studied oxide material in this context is rutile titanium dioxide [3]. However, also interfaces between SrTiO3 (STO) and organic molecules are studied increasingly using both experimental [4][5] and

A stretchable triboelectric nanogenerator made of silver-coated glass microspheres for human motion energy harvesting and self-powered sensing applications

• Hui Li,
• Yaju Zhang,
• Yonghui Wu,
• Hui Zhao,
• Weichao Wang,
• Xu He and
• Haiwu Zheng

Beilstein J. Nanotechnol. 2021, 12, 402–412, doi:10.3762/bjnano.12.32

• satisfies the needs of reliability for flexible tactile sensors in realizing human–machine interfaces. This work expands the potential application of S-TENGs from wearable electronics and smart sensing systems to real-time robotics control and virtual reality/augmented reality interactions. Keywords: human

Structural and optical characteristics determined by the sputtering deposition conditions of oxide thin films

• Petronela Prepelita,
• Florin Garoi and
• Valentin Craciun

Beilstein J. Nanotechnol. 2021, 12, 354–365, doi:10.3762/bjnano.12.29

• space science come with a new dimension of microstructural representation of advanced functional materials [10][11]. Metamaterial structures are of significant interest not only in space science but also in the fields of public security and sensors [9][10][11]. Materials with dielectric properties, such

• properties. Transparent oxides are an attractive class of plasmonic materials which are under intense study for their integration into low-loss metamaterial structures and a series of applications in transformation optics, sensors, and imaging. Here we used oxide thin films and studied their optical

Nickel nanoparticle-decorated reduced graphene oxide/WO₃ nanocomposite – a promising candidate for gas sensing

• Ilka Simon,
• Alexandr Savitsky,
• Rolf Mülhaupt,
• Vladimir Pankov and
• Christoph Janiak

Beilstein J. Nanotechnol. 2021, 12, 343–353, doi:10.3762/bjnano.12.28

• recovery rate. Also, it should work at low cost and with low power consumption [3]. In comparison to conventional gas sensors, nanostructure-based gas sensors are more sensitive because of their increased detection area [4]. The most common mode used in gas sensing is the resistance mode, where the change

• ][9]. Metal oxide semiconductors (MOS) are the most commonly used gas sensors [10]. MOS can be divided into n-type and p-type MOS. In n-type MOS electrons are the majority charge carriers, while in p-type MOS holes are the majority charge carriers [6]. The exposure to reducing gases causes a decrease

• forms a p–n heterojunction, which improves the gas sensing abilities significantly [25]. Carbon-based materials are also promising gas sensors, because of their high surface area and high chemical and thermal stability [26][27]. Pristine graphene is a good conductor but rather inactive for gas sorption

Intracranial recording in patients with aphasia using nanomaterial-based flexible electronics: promises and challenges

• Qingchun Wang and
• Wai Ting Siok

Beilstein J. Nanotechnol. 2021, 12, 330–342, doi:10.3762/bjnano.12.27

• preoperative evaluation and functional cortex mapping [44]. ECoG uses strips and grids of electrodes applied to the cortical surface in either subdural or epidural space (Figure 2a) [42]. For example, in a recent iEEG study (Figure 2b), multicontact sensors were implanted in different brain regions to collect

• sensors could be implanted for iEEG recording. Sensor group cortical surface (CS) are strips and grids of electrodes, and sensor groups trans-occipital (TO) and orthogonal-to-mesial (OM) represent in-depth electrodes. Figure 2b was reprinted from [45], Physiological Measurement, vol. 39, by A. Sanz-Garcia

• ; T. Rings; K. Lehnertz, “Impact of type of intracranial EEG sensors on link strengths of evolving functional brain networks”, article no. 074003, published 13 July 2018, https://doi.org/10.1088/1361-6579/aace94; © Institute of Physics and Engineering in Medicine. Reproduced with permission of IOP

The patterning toolbox FIB-o-mat: Exploiting the full potential of focused helium ions for nanofabrication

• Victor Deinhart,
• Lisa-Marie Kern,
• Jan N. Kirchhof,
• Sabrina Juergensen,
• Joris Sturm,
• Enno Krauss,
• Thorsten Feichtner,
• Sviatoslav Kovalchuk,
• Michael Schneider,
• Dieter Engel,
• Bastian Pfau,
• Bert Hecht,
• Kirill I. Bolotin,
• Stephanie Reich and
• Katja Höflich

Beilstein J. Nanotechnol. 2021, 12, 304–318, doi:10.3762/bjnano.12.25

• ], and graphene nanomechanical resonators have been employed as various sensors [42][43][44][45][46]. Yet, the sensitivity at room temperature is limited by a rather low quality factor. Patterning of the devices into trampoline-shaped resonators yields a large increase in quality factor and, thus, device

Gold(I) N-heterocyclic carbene precursors for focused electron beam-induced deposition

• Cristiano Glessi,
• Aya Mahgoub,
• Cornelis W. Hagen and
• Mats Tilset

Beilstein J. Nanotechnol. 2021, 12, 257–269, doi:10.3762/bjnano.12.21

• and some volatile fragments. The technique has been employed in applications such as the fabrication of nanoconnectors [5], extreme ultra-violet lithography (EUVL) mask repair [6], AFM probe tips [7][8][9], nanodevices for plasmonics [10], gas sensors [11][12], optoelectronics [13], and magnetic [14

Paper-based triboelectric nanogenerators and their applications: a review

• Jing Han,
• Nuo Xu,
• Yuchen Liang,
• Mei Ding,
• Junyi Zhai,
• Qijun Sun and
• Zhong Lin Wang

Beilstein J. Nanotechnol. 2021, 12, 151–171, doi:10.3762/bjnano.12.12

• ); paper-based sensors; self-powered devices; P-TENGs; triboelectric nanogenerator; Introduction Environmental pollution is an undeniable fact in our daily lives. The air pollution caused by industrial waste generation (gases/toxins) and by the combustion of fossil fuels is getting more and more serious

• [1][2]. Meanwhile, with the rapid growth of the Internet of Things (IoTs), the explosive growth of sensors has led to the massive use of batteries, which have also resulted in severe environmental issues in virtue of their short lifetime. In this regard, renewable energy sources, such as wind, wave

• pattering process results in porous MCG structures (with pore sizes ranging from hundreds of nanometers to several microns), which can be used in various applications, such as mechanical energy harvesting devices, chemical sensors, and electrochemical supercapacitors. Screen printing is a facile, efficient

Numerical analysis of vibration modes of a qPlus sensor with a long tip

• Kebei Chen,
• Zhenghui Liu,
• Yuchen Xie,
• Chunyu Zhang,
• Gengzhao Xu,
• Wentao Song and
• Ke Xu

Beilstein J. Nanotechnol. 2021, 12, 82–92, doi:10.3762/bjnano.12.7

• Sciences (CAS), Suzhou 215123, China CAS Key Laboratory of Nanophotonic Materials and Devices, Suzhou Institute of Nano-Tech and Nano-Bionics, Suzhou 215123, China 10.3762/bjnano.12.7 Abstract We study the oscillatory behavior of qPlus sensors with a long tilted tip by means of finite element simulations

• horizontally and vertically. The vibration characteristics of qPlus sensors with different tip sizes were studied. An optimized tip size was derived from obtained values of tip amplitude, ratio between vertical and lateral amplitude components, output current, and quality factor. For high spatial resolution

• . Here, we report a numerical study of the vibration modes of qPlus sensors. Eigenfrequencies, tip amplitudes, ratios between vertical and lateral amplitude components, output currents, and Q factor values as functions of the tip size of the qPlus sensor are systematically analyzed. Eventually, the

ZnO and MXenes as electrode materials for supercapacitor devices

• Ameen Uddin Ammar,
• Ipek Deniz Yildirim,
• Feray Bakan and
• Emre Erdem

Beilstein J. Nanotechnol. 2021, 12, 49–57, doi:10.3762/bjnano.12.4

• gaining more popularity. ZnO is an inherently highly defective material with a large bandgap energy at room temperature. It is one the most extensively studied prototype semiconductors regarding defect structures. The intrinsic point defects play a crucial role in device performance regarding sensors

Bio-imaging with the helium-ion microscope: A review

• Matthias Schmidt,
• James M. Byrne and
• Ilari J. Maasilta

Beilstein J. Nanotechnol. 2021, 12, 1–23, doi:10.3762/bjnano.12.1

• instrument, and which holds promise to conduct exciting THIM experiments also on biological samples [58]. Secondly, within the npSCOPE H2020 project an “instrument [is being developed] that couples the extraordinarily high resolution of the […] helium-ion microscope with sensors for composition (a mass

Piezotronic effect in AlGaN/AlN/GaN heterojunction nanowires used as a flexible strain sensor

• Jianqi Dong,
• Liang Chen,
• Yuqing Yang and
• Xingfu Wang

Beilstein J. Nanotechnol. 2020, 11, 1847–1853, doi:10.3762/bjnano.11.166

• effect; strain sensors; strain tests; top-down method; Introduction Due to the non-centrosymmetric structure of the group-III nitride semiconductor materials (e.g., GaN, AlN, and AlGaN), spontaneous polarization (Psp) and piezoelectric polarization induced by lattice mismatch (Plm) are inevitably

• based on the 1D quantum confinement effect. Hence, the unique electrical and optical properties of 1D semiconductor NWs have attracted research interest from the field of nanogenerators [11][12][13][14] and NW-based strain sensors [15][16][17][18][19]. Strain sensors can convert mechanical deformation

• , AlGaN/AlN/GaN NWs with high electron mobility, carrier density, and mechanical flexibility have become good candidates for highly sensitive and flexible strain sensors. In this work, we use a top-down two-step process, including inductively coupled plasma (ICP) dry etching and selective electrochemical

Functional nanostructures for electronics, spintronics and sensors

• Anatolie S. Sidorenko

Beilstein J. Nanotechnol. 2020, 11, 1704–1706, doi:10.3762/bjnano.11.152

• Anatolie S. Sidorenko D. Ghitu Institute of Electronic Engineering and Nanotechnologies, Chisinau, Moldova and Orel State University, Orel, Russia 10.3762/bjnano.11.152 Keywords: functional nanostructures; nanoelectronics; post-Moore generation; sensors; spintronics; supercomputers

• coupled superconducting nanowires with quantum phase slips which may be used for interpretation of already existing experiments on meander-like nanowires and for the design of a novel set of superconducting sensors. Another very promising photon detector [16] was demonstrated for supersensitive detection

• applications for quantum electronics and spintronics. In addition to these highlighted works, there are also other interesting functional nanostructures, sensors and quantum detectors presented, to highlight the fascinating world of nanoelectronics. The concept of this thematic issue emerged during the

Piezoelectric sensor based on graphene-doped PVDF nanofibers for sign language translation

• Shuai Yang,
• Xiaojing Cui,
• Rui Guo,
• Zhiyi Zhang,
• Shengbo Sang and
• Hulin Zhang

Beilstein J. Nanotechnol. 2020, 11, 1655–1662, doi:10.3762/bjnano.11.148

• . Nowadays, pressure and bending angle sensors are mainly based on signals caused by a changing force [17][18][19][20][21][22][23][24][25]. Plenty of measurement methods, using different materials and different principles, have been proposed in recent years [26]. Although these sensors can detect various

• interactions between humans and machines, the indispensability of external power sources greatly narrow their application scopes [27][28][29][30][31][32][33][34][35]. Piezoelectric sensors generate self-responsive electrical signals based on external mechanical forces. As a self-powered sensing system

• , piezoelectric sensors show potential in wearable sensing applications [19][36][37][38][39][40][41]. However, traditional piezoelectric sensor devices such as piezoelectric ceramics have disadvantages in detecting bending, and their detection stability and measurement range need to be improved [18][42][43][44

Selective detection of complex gas mixtures using point contacts: concept, method and tools

• Alexander P. Pospelov,
• Victor I. Belan,
• Dmytro O. Harbuz,
• Volodymyr L. Vakula,
• Lyudmila V. Kamarchuk,
• Yuliya V. Volkova and
• Gennadii V. Kamarchuk

Beilstein J. Nanotechnol. 2020, 11, 1631–1643, doi:10.3762/bjnano.11.146

• 10.3762/bjnano.11.146 Abstract Of all modern nanosensors using the principle of measuring variations in electric conductance, point-contact sensors stand out in having a number of original sensor properties not manifested by their analogues. The nontrivial nature of point-contact sensors is based on the

• unique properties of Yanson point contacts used as the sensing elements. The quantum properties of Yanson point contacts enable the solution of some of the problems that could not be solved using conventional sensors measuring conductance. In the present paper, we demonstrate this by showing the

• potential of quantum point-contact sensors to selectively detect components of a gas mixture in real time. To demonstrate the high efficiency of the proposed approach, we analyze the human breath, which is the most complex of the currently known natural gas mixtures with extremely low concentrations of its

A self-powered, flexible ultra-thin Si/ZnO nanowire photodetector as full-spectrum optical sensor and pyroelectric nanogenerator

• Liang Chen,
• Jianqi Dong,
• Miao He and
• Xingfu Wang

Beilstein J. Nanotechnol. 2020, 11, 1623–1630, doi:10.3762/bjnano.11.145

• energy. This is achieved by utilizing the temperature dependence of electric displacement of polar materials, which are already applied in solar cells, photodetectors, temperature sensors, and stretchable electronics [15][16][17][18]. It means that the PENGs could serve as a power source to power PDs by

Oxidation of Au/Ag films by oxygen plasma: phase separation and generation of nanoporosity

• Abdel-Aziz El Mel,
• Said A. Mansour,
• Mujaheed Pasha,
• Atef Zekri,
• Janarthanan Ponraj,
• Akshath Shetty and
• Yousef Haik

Beilstein J. Nanotechnol. 2020, 11, 1608–1614, doi:10.3762/bjnano.11.143

• oxygen, solid-state diffusion in metal alloys as well as the Kirkendall effect. The nanoporous microspheres generated by the silver oxidation within the Au/Ag alloy film might have potential applications to the field of gas sensors and catalysis since those require nanoporous semiconductor materials with

Walking energy harvesting and self-powered tracking system based on triboelectric nanogenerators

• Mingliang Yao,
• Guangzhong Xie,
• Qichen Gong and
• Yuanjie Su

Beilstein J. Nanotechnol. 2020, 11, 1590–1595, doi:10.3762/bjnano.11.141

• excellent performance, which can be used as motion [35][36][37] and temperature sensors [38][39], UV detectors [40], tactile sensors [41][42][43], sensors for healthcare [44][45][46][47], humidity sensors, and gas sensors [48][49][50][51], for example. In this work, a flexible undulated electrode-based

• , including men, women and children. In addition, integrated with six sensing channels along a public aisle, a self-powered location-tracking system was constructed for pedestrian volume counting and passenger tracing. This work paves the way for the application of triboelectric sensors in intelligent cities

Design of V-shaped cantilevers for enhanced multifrequency AFM measurements

• Mehrnoosh Damircheli and
• Babak Eslami

Beilstein J. Nanotechnol. 2020, 11, 1525–1541, doi:10.3762/bjnano.11.135

• systems (MEMS), superparamagnetic particle embedded microprobe (SPEM) sensors, or lab-on chips devices [5][6][7][8]. Microcantilevers are also an important component of atomic force microscopes (AFM). Due to their importance in AFM, there have been many studies on modeling the cantilevers to represent the

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

• significantly boost the performance of modern sensors, energy storage devices, or energy harvesters and have become essential in their development. These structures can either be well-defined regular structures fabricated in a top-down process, or self-assembled random structures from bottom-up processes. These

• platform and can be adapted to detect biomolecules [9]. Silicon nanowires are used as template for cancer sensors. The nanowires are implemented as gate in integrated sensing FETs [10][11]. A wide range of chemical sensors and biosensors benefit from porous silicon structures [12]. All these presented

• demonstrate a wafer-level integration of high aspect ratio nanoporous templates. These self-assembled silicon nanostructures are locally defined. This is the basis of a local platform of high specific surface area for the fabrication of functional devices such as sensors, harvesters, or energy storage devices

Protruding hydrogen atoms as markers for the molecular orientation of a metallocene

• Linda Laflör,
• Michael Reichling and
• Philipp Rahe

Beilstein J. Nanotechnol. 2020, 11, 1432–1438, doi:10.3762/bjnano.11.127

• experiments (5 and 77 K) with qPlus sensors as well as at room temperature using silicon cantilevers [22]. Although the NC-AFM tips were not functionalised, i.e., not specifically terminated with atoms or molecules for imaging, we find a very good agreement between the experimental data and probe particle

• instrument (ScientaOmicron GmbH, Taunusstein, Germany), while experiments on thin films used a ScientaOmicron LT qPlus gen.II machine, both operated with a MATRIX controller. W tips attached to tuning fork sensors in qPlus configuration [29] were used in both systems. For the measurements on thin film

• samples, custom-built sensors were fabricated with a separate tunnelling current wire to exclude cross-talk between the NC-AFM and tunnelling current signals [30], while sensors as supplied by the manufacturer were used for measurements on bulk CaF2 samples. Sensors were excited to oscillation amplitudes

Triboelectric nanogenerator based on Teflon/vitamin B1 powder for self-powered humidity sensing

• Liangyi Zhang,
• Huan Li,
• Yiyuan Xie,
• Jing Guo and
• Zhiyuan Zhu

Beilstein J. Nanotechnol. 2020, 11, 1394–1401, doi:10.3762/bjnano.11.123

• environment has been increasing due to the current life habits of the population [5][6][7]. Moreover, a variety of sensors are often placed in severe environmental conditions, which might restrict their power supply options [8][9][10][11][12]. As a result, several lines of research have been focused on the

• systems can be mitigated [17][18][19][20][21]. Hence, the investigation of self-powered sensors which harvest energy from the surrounding environment is highly sustainable. Triboelectric nanogenerators (TENGs) have been growing in popularity for use as a novel technology to harvest energy. TENGs have a

• ]. Recently, TENG-based sensors have attracted increased attention [34][35][36][37][38][39][40][41]. In 2014, Ga-doped ZnO was used for the fabrication of piezo-humidity sensors with a high sensitivity and a fast response [42]. In 2018, Vivekananthan et al. proposed sustainable energy harvesting and battery