Fabrication and characterization of Si_1−xGe_x nanocrystals in as-grown and annealed structures: a comparative study

• Muhammad Taha Sultan,
• Adrian Valentin Maraloiu,
• Ionel Stavarache,
• Jón Tómas Gudmundsson,
• Andrei Manolescu,
• Valentin Serban Teodorescu,
• Magdalena Lidia Ciurea and
• Halldór Gudfinnur Svavarsson

Beilstein J. Nanotechnol. 2019, 10, 1873–1882, doi:10.3762/bjnano.10.182

• confinement. These NCs present unique and interesting size-dependent physical properties for a wide range of application including lighting, non-volatile memories, and electronic and photovoltaic applications [1][2][3]. SiGe nanostructures exhibit a stronger quantum confinement effect than Si NCs [4] and have

• above which the interface effect prevails and below which the photoresponse is associated with quantum confinement. That is, size and surface chemistry of the NCs and oxygen-related bonds are the factors determining the photocurrent spectra. It is well understood that annealing results in the formation

Construction of a 0D/1D composite based on Au nanoparticles/CuBi₂O₄ microrods for efficient visible-light-driven photocatalytic activity

• Weilong Shi,
• Mingyang Li,
• Hongji Ren,
• Feng Guo,
• Xiliu Huang,
• Yu Shi and
• Yubin Tang

Beilstein J. Nanotechnol. 2019, 10, 1360–1367, doi:10.3762/bjnano.10.134

• ) 0D nanomaterials with quantum confinement effect are ideal materials in the field of photocatalysis; (iii) 0D nanomaterials could provide more active sites, further enhancing the separation of photogenerated carriers of the 1D substrate materials; (iv) the intimate bonding of two kinds of dimensional

A biomimetic nanofluidic diode based on surface-modified polymeric carbon nitride nanotubes

• Kai Xiao,
• Baris Kumru,
• Lu Chen,
• Lei Jiang,
• Bernhard V. K. J. Schmidt and
• Markus Antonietti

Beilstein J. Nanotechnol. 2019, 10, 1316–1323, doi:10.3762/bjnano.10.130

• with electron-rich –NH terminal groups. The negative surface charge is a crucial factor in ion transport. To confirm that confinement effects as well as the surface charge control the ion-transport properties [36][37][38], we measured the conductance of KCl electrolyte both in bulk solution and across

CuInSe₂ quantum dots grown by molecular beam epitaxy on amorphous SiO₂ surfaces

• Henrique Limborço,
• Pedro M.P. Salomé,
• Rodrigo Ribeiro-Andrade,
• Jennifer P. Teixeira,
• Nicoleta Nicoara,
• Kamal Abderrafi,
• Joaquim P. Leitão,
• Juan C. Gonzalez and
• Sascha Sadewasser

Beilstein J. Nanotechnol. 2019, 10, 1103–1111, doi:10.3762/bjnano.10.110

• bandgap and in agreement with the distribution of sizes. A blue-shift of the luminescence is observed as the average size of the nanodots gets smaller, evidencing quantum confinement in all samples. By using simple quantum confinement calculations, we correlate the photoluminescence peak emission energy

• show in detail the spectra in Figure 4c–e. The dashed line indicates the bulk bandgap of CIS (1.04–1.05 eV) [45][46]. It is clear that all samples show peak emission at energies above the bulk bandgap, which we preliminarily explain by a quantum confinement effect due to the small mean size of the

• nanodots presented in Figure 1. With increasing substrate temperature, the mean size of the nanodots increases, leading to reduced quantum confinement effect and a red-shift of the PL emission to values closer to the CIS bandgap. To analyse the CIS emission in more detail and independently of the

Fe₃O₄ nanoparticles as a saturable absorber for giant chirped pulse generation

• Ji-Shu Liu,
• Xiao-Hui Li,
• Abdul Qyyum,
• Yi-Xuan Guo,
• Tong Chai,
• Hua Xu and
• Jie Jiang

Beilstein J. Nanotechnol. 2019, 10, 1065–1072, doi:10.3762/bjnano.10.107

• . In addition, FONPs also exhibit nonlinear photonic properties such as two-photon absorption, nonlinear scattering, and optical confinement [1][2]. Ferrous ferric oxide (Fe3O4) is a transition metal oxide that has a large third-order nonlinear optical susceptibility of χ(3) = 4.0 × 10−10 esu and an

Structural and optical properties of penicillamine-protected gold nanocluster fractions separated by sequential size-selective fractionation

• Xiupei Yang,
• Zhengli Yang,
• Fenglin Tang,
• Jing Xu,
• Maoxue Zhang and
• Martin M. F. Choi

Beilstein J. Nanotechnol. 2019, 10, 955–966, doi:10.3762/bjnano.10.96

• was investigated at room temperature. The results show that the peak emission energy of the size-selected AuNCs undergoes a blue shift when the size is decreased, which can be attributed to the quantum confinement effect. Keywords: gold nanoclusters; monolayer-protected gold nanoclusters; sequential

• energies on nanocluster sizes indicates that the optical luminescence of the samples comes from the quantum confinement effect. The band gap of the NCs increases with a decrease in the dimension of the AuNC quantum structure. Conclusion In this research, a highly polydisperse penicillamine-protected AuNC

Trapping polysulfide on two-dimensional molybdenum disulfide for Li–S batteries through phase selection with optimized binding

• Sha Dong,
• Xiaoli Sun and
• Zhiguo Wang

Beilstein J. Nanotechnol. 2019, 10, 774–780, doi:10.3762/bjnano.10.77

• shuttle effect. The shuttle effect aggravates the cyclic performance of the Li–S battery. During recent years, many approaches have been devoted to suppressing the shuttle effect and improving the conductivity. Physical confinement of LPSs within host materials with large surface area, such as carbon

• nanotubes and porous materials, has been a common strategy to minimize the leakage of LPSs. However, the function of physical confinement is limited, and it slows down diffusion for ionic transport [9]. The addition of anchoring materials into the cathodes with a strong binding affinity to LPSs was thought

Outstanding chain-extension effect and high UV resistance of polybutylene succinate containing amino-acid-modified layered double hydroxides

• Adam A. Marek,
• Vincent Verney,
• Christine Taviot-Gueho,
• Grazia Totaro,
• Laura Sisti,
• Annamaria Celli and
• Fabrice Leroux

Beilstein J. Nanotechnol. 2019, 10, 684–695, doi:10.3762/bjnano.10.68

• available surface area per unit charge of ≈24 Å2, a value close to that required by histidine in a parallel orientation (≈26–29 Å2/e−). This interlayer arrangement suggests an important confinement of histidine molecules between LDH layers. This may explain the presence of co-intercalated nitrate ions

Ultrasonication-assisted synthesis of CsPbBr₃ and Cs₄PbBr₆ perovskite nanocrystals and their reversible transformation

• Longshi Rao,
• Xinrui Ding,
• Xuewei Du,
• Guanwei Liang,
• Yong Tang,
• Kairui Tang and
• Jin Z. Zhang

Beilstein J. Nanotechnol. 2019, 10, 666–676, doi:10.3762/bjnano.10.66

• ) structures of Cs4PbX6 NCs can be achieved, demonstrating a crystalline structure with well-separated octahedra [PbBr6]4− isolated by Cs+ ions [12][13]. This specific structure is expected to result in strong quantum confinement and electron–phonon interactions. This inspires researchers to further explore

A carrier velocity model for electrical detection of gas molecules

• Ali Hosseingholi Pourasl,
• Sharifah Hafizah Syed Ariffin,
• Mohammad Taghi Ahmadi,
• Razali Ismail and
• Niayesh Gharaei

Beilstein J. Nanotechnol. 2019, 10, 644–653, doi:10.3762/bjnano.10.64

• following form: where a1 and a2 are the lattice vectors. After calculation of the determinant of the matrix above, and applying the Taylor expansion and the quantum confinement effect [25] due to the finite width, the energy dispersion relation can be obtained for AGNR considering the gas molecules

Coexisting spin and Rabi oscillations at intermediate time regimes in electron transport through a photon cavity

• Vidar Gudmundsson,
• Hallmann Gestsson,
• Nzar Rauf Abdullah,
• Chi-Shung Tang,
• Andrei Manolescu and
• Valeriu Moldoveanu

Beilstein J. Nanotechnol. 2019, 10, 606–616, doi:10.3762/bjnano.10.61

• the parabolic confinement energy of the leads and the central system = 2.0 meV, together with the cyclotron frequency ωc = (eBext)/(m*c) produce an effective characteristic confinement energy and an effective magnetic length This characteristic length scale is approximately 23.8 nm for the

• in a short quantum wire of length Lx = 180 nm ≈ 7.6aw, where aw = 23.8 nm is the effective magnetic length for transverse magnetic field Bext = 0.1 T and parabolic confinement energy = 2.0 meV of the short wire and leads in the y-direction. The white gaps at x ≈ ±3.8aw indicate the onset of the semi

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

• enhancement responsible for the exquisite sensitivity of SERS is a combination of both electromagnetic field effects and chemical effects [6][7][8][9][10]. It has been accepted that the dominant electromagnetic enhancement mechanism (EM) is the nanoscale field confinement associated with localized surface

A porous 3D-RGO@MWCNT hybrid material as Li–S battery cathode

• Yongguang Zhang,
• Jun Ren,
• Yan Zhao,
• Taizhe Tan,
• Fuxing Yin and
• Yichao Wang

Beilstein J. Nanotechnol. 2019, 10, 514–521, doi:10.3762/bjnano.10.52

• structure. When used in Li–S batteries, the 3D porous lattice matrix not only accommodates a high content of sulfur, but also induces a confinement effect towards polysulfide, and thereby reduces the “shuttle effect”. The as-prepared S-3D-RGO@MWCNT composite delivers an initial specific capacity of 1102

• sites for strong S–metal bonding that have been reported to suppress the shuttle effect in polysulfides [13][14][15][16]. Moreover, designing metal oxides into various unique morphologies, e.g., hollow structures, can also provide a physical (or structural) confinement for sulfur [17]. Metal-oxide

• performance of S-3D-RGO@MWCNT indicates the efficient confinement of sulfur preventing the loss of active material through the shuttle effect. Figure 7a reveals the charge–discharge voltage profiles of the batteries measured at various rates across the voltage range of 1.5 to 3.0 V. A two-plateau behaviour of

Temperature-dependent Raman spectroscopy and sensor applications of PtSe₂ nanosheets synthesized by wet chemistry

• Mahendra S. Pawar and
• Dattatray J. Late

Beilstein J. Nanotechnol. 2019, 10, 467–474, doi:10.3762/bjnano.10.46

• , etc. from group IV–V and X represents the chalcogenides family, X = S, Se, Te, etc. The metal atom M is sandwiched between layers of chalcogenide (X) atoms in the structure X–M–X. The TMDCs show diverse functional properties at the monolayer level in contrast to bulk due to the quantum confinement

Sub-wavelength waveguide properties of 1D and surface-functionalized SnO₂ nanostructures of various morphologies

• Venkataramana Bonu,
• Binaya Kumar Sahu,
• Arindam Das,
• Sankarakumar Amirthapandian,
• Sandip Dhara and
• Harish C. Barshilia

Beilstein J. Nanotechnol. 2019, 10, 379–388, doi:10.3762/bjnano.10.37

• (n = 2.1) enables photonic confinement in the NW cavities. The observed waveguide nature arises from defect-controlled luminescence in the visible light range of SnO2 and detailed discussion is provided in the photoluminescence study section. For understanding the propagation of luminescence through

Transport signatures of an Andreev molecule in a quantum dot–superconductor–quantum dot setup

• Zoltán Scherübl,
• András Pályi and
• Szabolcs Csonka

Beilstein J. Nanotechnol. 2019, 10, 363–378, doi:10.3762/bjnano.10.36

• , nanodevices provide the confinement of electrons into 1D or 0D. The interplay of these properties is a key ingredient of novel promising qubit realizations, such as Majorana qubits [1][2] and Andreev qubits [3]. The basic physical mechanism behind these applications is the Andreev reflection, when a Cooper

Removal of toxic heavy metals from river water samples using a porous silica surface modified with a new β-ketoenolic host

• Said Tighadouini,
• Smaail Radi,
• Abderrahman Elidrissi,
• Khadija Haboubi,
• Maryse Bacquet,
• Stéphanie Degoutin,
• Mustapha Zaghrioui and
• Yann Garcia

Beilstein J. Nanotechnol. 2019, 10, 262–273, doi:10.3762/bjnano.10.25

• affinity and adsorption capacity for toxic heavy metal detection with less equilibrium time, a discovery that has significant environmental issues. Parameters that may improve the retention effectiveness of the metal ions have also been studied. The system was used for the confinement of lead, cadmium

Magnetic-field sensor with self-reference characteristic based on a magnetic fluid and independent plasmonic dual resonances

• Kun Ren,
• Xiaobin Ren,
• Yumeng He and
• Qun Han

Beilstein J. Nanotechnol. 2019, 10, 247–255, doi:10.3762/bjnano.10.23

• fabrication and compactness. In recent years, compact optical devices based on surface plasmon polaritons (SPPs) have been reported. SPPs propagate along the dielectric–metal interface with the amplitudes decaying exponentially into both sides [16]. The deep subwavelength confinement of SPPs leads to the

Surface plasmon resonance enhancement of photoluminescence intensity and bioimaging application of gold nanorod@CdSe/ZnS quantum dots

• Siyi Hu,
• Yu Ren,
• Yue Wang,
• Jinhua Li,
• Junle Qu,
• Liwei Liu,
• Hanbin Ma and
• Yuguo Tang

Beilstein J. Nanotechnol. 2019, 10, 22–31, doi:10.3762/bjnano.10.3

• and they show excellent quantum confinement for charge carrier and lattice mismatch. In such cases, the energy range of the QDs depends on the relative conduction and valence band offsets for the two materials, and this characteristic can enable many chemical materials or biomolecules to conjugate

• suggests that when metal or chemical materials are doped with QDs, the number of surface trap states (which can lead to exponential PL decay) is affected by the surface passivation and by the degree of quantum confinement. In CdSe/ZnS QDs with higher defect densities, binding with GNRs having very

Zn/F-doped tin oxide nanoparticles synthesized by laser pyrolysis: structural and optical properties

• Florian Dumitrache,
• Iuliana P. Morjan,
• Elena Dutu,
• Ion Morjan,
• Claudiu Teodor Fleaca,
• Monica Scarisoreanu,
• Alina Ilie,
• Marius Dumitru,
• Cristian Mihailescu,
• Adriana Smarandache and
• Gabriel Prodan

Beilstein J. Nanotechnol. 2019, 10, 9–21, doi:10.3762/bjnano.10.2

• SnO2 in its undoped form is an n-type semiconductor with a direct bandgap of 3.6 eV at room temperature. Its n-type conductivity is due to oxygen vacancies in its rutile structure. The bandgap, starting from the bulk value, increases as the size of the nanocrystal decreases, due to electron confinement

Apparent tunneling barrier height and local work function of atomic arrays

• Neda Noei,
• Alexander Weismann and
• Richard Berndt

Beilstein J. Nanotechnol. 2018, 9, 3048–3052, doi:10.3762/bjnano.9.283

• effectively raises the energy required to overcome the potential barrier between the tip and the sample. In the context of the scanning tunneling microscope, the idea of an increased barrier due to lateral confinement has been attributed to J. Tersoff in [27]. Lateral confinement plays a key role in ballistic

• is of the order of 1 eV. This complicates the relation between the local sample work function Φ and the measured Φapp. The shape of the tip also influences the degree of confinement and presumably contributes to the scatter of Φapp observed with different tips. STM images of a Cu(111) surface with

Site-controlled formation of single Si nanocrystals in a buried SiO₂ matrix using ion beam mixing

• Xiaomo Xu,
• Thomas Prüfer,
• Daniel Wolf,
• Hans-Jürgen Engelmann,
• Lothar Bischoff,
• René Hübner,
• Karl-Heinz Heinig,
• Wolfhard Möller,
• Stefan Facsko,
• Johannes von Borany and
• Gregor Hlawacek

Beilstein J. Nanotechnol. 2018, 9, 2883–2892, doi:10.3762/bjnano.9.267

• exception of optical applications. The latter is due to its indirect band gap in the bulk state. Benefiting from their reduced size, Si NCs show optical activity [1][2] and quantum confinement behavior [3] and have inspired novel applications in microelectronics [4], optics [1] and photovoltaics [5][6]. In

• fluence of 172 Si+ nm−2 at 60 keV, the O/Si atomic ratio in the center of the oxide has decreased below 1.5. After simulated annealing, a Si NC band forms close to the interface. Due to the geometric confinement only one layer of silicon NCs forms in the center of the buried oxide layer. Here, a lower

Low cost tips for tip-enhanced Raman spectroscopy fabricated by two-step electrochemical etching of 125 µm diameter gold wires

• Antonino Foti,
• Francesco Barreca,
• Enza Fazio,
• Cristiano D’Andrea,
• Paolo Matteini,
• Onofrio Maria Maragò and
• Pietro Giuseppe Gucciardi

Beilstein J. Nanotechnol. 2018, 9, 2718–2729, doi:10.3762/bjnano.9.254

• tip is the key element in TERS. Its field enhancement and confinement capabilities determine the signal amplification, the spatial resolution and the reproducibility of the results. The material, morphology, aspect ratio and size of the tip apex are expected to determine the optical properties of the

• supported by TERS mapping of a 150 × 150 nm2 area (30 × 30 points) with step size of 5 nm (Figure 10a) in a different zone of the sample in which R6G absorbs in a patchy-like fashion. Spectra acquired on adjacent points (Figure 10b) show the capability to map the confinement of R6G molecules in a region

Size-selected Fe₃O₄–Au hybrid nanoparticles for improved magnetism-based theranostics

• Maria V. Efremova,
• Yulia A. Nalench,
• Eirini Myrovali,
• Anastasiia S. Garanina,
• Ivan S. Grebennikov,
• Polina K. Gifer,
• Maxim A. Abakumov,
• Marina Spasova,
• Makis Angelakeris,
• Alexander G. Savchenko,
• Michael Farle,
• Natalia L. Klyachko,
• Alexander G. Majouga and
• Ulf Wiedwald

Beilstein J. Nanotechnol. 2018, 9, 2684–2699, doi:10.3762/bjnano.9.251

• (modeled r2 = 255 mM−1·s−1) in MAR. The confinement of the NPs in an agarose matrix hinders or at least slows down the diffusion of water molecules near NPs and therefore decreasing r2 values are obtained. Although the theoretical limit [66] for MNP-25 and MNP-44 in SDR of ≈1000 mM−1·s−1 (given their high

Two-dimensional semiconductors pave the way towards dopant-based quantum computing

• José Carlos Abadillo-Uriel,
• Belita Koiller and
• María José Calderón

Beilstein J. Nanotechnol. 2018, 9, 2668–2673, doi:10.3762/bjnano.9.249

• qubits. We distinguish 2D materials that support shallow states with binding energies and Bohr radii comparable to P in Si, and those that support stronger confinement. Each group of materials could serve different purposes with shallower states more suitable for manipulation and deeper ones for storage