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

• , different information can be derived from the measurement of the Raman features (frequencies, linewidths, and intensities) of intralayer phonon modes as well as those of the interlayer modes, the so-called layer breathing (LB) modes and shear (S) modes. Recently, we have developed the reproducible direct

• of the results. The first parameter is the wavelength of the incident laser light used in the Raman experiments. As it will be detailed in the following, the measurements of the frequencies, linewidths, and intensity of first-order Raman active phonon modes of MoS2 have to be obtained with good

• accuracy in order to evaluate the thickness of a MoS2 flake. These phonons modes are (i) the in-plane phonon mode involving relative motion of Mo and S atoms with E′ symmetry for a monolayer (E12g for bulk) and (ii) the out-of-plane phonon mode involving only out-of-plane motions of S atoms with A′1

Density functional theory study of Au-fcc/Ge and Au-hcp/Ge interfaces

• Olga Sikora,
• Małgorzata Sternik,
• Benedykt R. Jany,
• Franciszek Krok,
• Przemysław Piekarz and
• Andrzej M. Oleś

Beilstein J. Nanotechnol. 2023, 14, 1093–1105, doi:10.3762/bjnano.14.90

• principles calculations of the cohesive energy and elastic constants as well as phonon dispersion relations show stability of both hcp and dhcp polytypes of gold [24]. Ab initio studies indicate higher stability of the fcc phase and a tendency towards hcp → fcc phase transformation. However, the calculated

Nanoarchitectonics of photothermal materials to enhance the sensitivity of lateral flow assays

• Elangovan Sarathkumar,
• Rajasekharan S. Anjana and
• Ramapurath S. Jayasree

Beilstein J. Nanotechnol. 2023, 14, 988–1003, doi:10.3762/bjnano.14.82

• are likely to occur, namely (i) the relaxation of electrons from non-Fermi levels to the Fermi level (electron–electron scattering), (ii) the cooling of hot electron gas through electron–phonon scattering, and (iii) the emission of heat to the surrounding (phonon–phonon scattering) (Figure 4A,B). The

Isolation of cubic Si₃P₄ in the form of nanocrystals

• Polina K. Nikiforova,
• Sergei S. Bubenov,
• Vadim B. Platonov,
• Andrey S. Kumskov,
• Nikolay N. Kononov,
• Tatyana A. Kuznetsova and
• Sergey G. Dorofeev

Beilstein J. Nanotechnol. 2023, 14, 971–979, doi:10.3762/bjnano.14.80

• discernible shoulder at ca. 350 cm−1, a weak band centered at 170 cm−1, as well as a broad band centered at 475 cm−1 with a shoulder at ca. 525 cm−1. The band at a wavenumber of 525 cm−1 can plausibly be designated to the highest-frequency Si–P vibration as the Γ-point optical phonon of Si is positioned at

In situ magnesiothermic reduction synthesis of a Ge@C composite for high-performance lithium-ion batterie anodes

• Ha Tran Huu,
• Ngoc Phi Nguyen,
• Vuong Hoang Ngo,
• Huy Hoang Luc,
• Minh Kha Le,
• Minh Thu Nguyen,
• My Loan Phung Le,
• Hye Rim Kim,
• In Young Kim,
• Sung Jin Kim,
• Van Man Tran and
• Vien Vo

Beilstein J. Nanotechnol. 2023, 14, 751–761, doi:10.3762/bjnano.14.62

• Figure 1c, the Raman spectrum of pure Ge exhibits a signal at 83 cm−1, attributed to the transverse acoustic phonon mode, and two peaks at 127 and 169 cm−1 ascribed, respectively, to the longitudinal acoustic and longitudinal optic phonon modes of Ge–Ge bonds [40][41]. The sharp peak at 296 cm−1 and a

• low-intensity band around 550 cm−1 are assigned to the first-order and second-order transverse optic phonon modes of crystalline Ge [41][42][43]. Moreover, the broadband detected at 449 cm−1 corresponds to the customary Raman-active motion of α-GeO2 [44]. The presence of characteristic signals in the

Control of morphology and crystallinity of CNTs in flame synthesis with one-dimensional reaction zone

• Muhammad Hilmi Ibrahim,
• Norikhwan Hamzah,
• Mohd Zamri Mohd Yusop,
• Ni Luh Wulan Septiani and
• Mohd Fairus Mohd Yasin

Beilstein J. Nanotechnol. 2023, 14, 741–750, doi:10.3762/bjnano.14.61

• defects and disorders of the sp2-hybridized sidewalls, while the G′ peak at 2500–2900 cm−1 represents photon–phonon interactions [27]. The absence of a low-frequency peak below 200 cm−1, usually assigned to the A1g symmetry radial breathing mode, which is the main characteristic of SWCNTs [28], indicates

Thermal transport in kinked nanowires through simulation

• Alexander N. Robillard,
• Graham W. Gibson and
• Ralf Meyer

Beilstein J. Nanotechnol. 2023, 14, 586–602, doi:10.3762/bjnano.14.49

• completely understood. The behaviour of the conductance is examined as kinks of varying angular intensity are included into nanowires. The effects on thermal transport are evaluated through molecular dynamics simulations, phonon Monte Carlo simulations and classical solutions of the Fourier equation. A

• phonon reflection specularity on the heat flux is also examined. It is found that, in general, the flow of heat through systems simulated through phonon Monte Carlo methods is concentrated into a channel smaller than the wire dimensions, while this is not the case in the classical solutions of the

• Fourier model. Keywords: ballistic transport; kinked nanowire; molecular dynamics; phonon Monte Carlo; thermal transport; Introduction The thermal conductivity of semiconductor nanostructures is of great interest because of potential applications in a wide variety of fields, such as thermal control

Transferability of interatomic potentials for silicene

• Marcin Maździarz

Beilstein J. Nanotechnol. 2023, 14, 574–585, doi:10.3762/bjnano.14.48

• (TDS), honeycomb dumbbell (HDS), and large honeycomb dumbbell (LHDS) silicene [8]. There are still doubts about their dynamic stability. For example, for a flat phase, the negative ZO phonon mode could be removed by the selection of an appropriate substrate [3][9]. The ability of potentials for 3D

• -principles method and then to test the ability of different interatomic potentials to reproduce these properties. Methods Analyzing the available literature concerning all phases of single-layer Si, it is not feasible to find all structural, mechanical, and phonon data obtained in one consistent way. The

• cohesive energy, average bond length, average height, 2D elastic constants, as well as phonon data are determined here using a single consistent first-principles approach as described in the next section “Ab initio calculations”. These data were further considered as reference data and marked as “valueDFT

Plasmonic nanotechnology for photothermal applications – an evaluation

• A. R. Indhu,
• L. Keerthana and
• Gnanaprakash Dharmalingam

Beilstein J. Nanotechnol. 2023, 14, 380–419, doi:10.3762/bjnano.14.33

• effective localization of the incident photon energy, and the decay of this oscillation (through phenomena such as electron–electron, electron–phonon, and electron–surface scattering) releases the absorbed energy into the lattice as heat (or as photons), often making them efficient tunable PT energy

• -radiative relaxation occurs through the sequential processes of hot carrier generation, electron thermalization, and finally electron–phonon coupling heat transfer [65], leading to a temperature increase of the lattice (Figure 8 [66] and Figure 9). Thus, the energy exchange between energetic plasmons and

• the phonon modes leads to an increase in temperature of the metal nanoparticles, and the ultimate conduction of this heat to the surrounding. The exchange time will vary for small nanoparticles due to quantum confinement effects [65] observed when the size of the nanoparticle is comparable to the Bohr

Intermodal coupling spectroscopy of mechanical modes in microcantilevers

• Ioan Ignat,
• Bernhard Schuster,
• Jonas Hafner,
• MinHee Kwon,
• Daniel Platz and
• Ulrich Schmid

Beilstein J. Nanotechnol. 2023, 14, 123–132, doi:10.3762/bjnano.14.13

• mode splitting is a good way to measure the coupling rates. Here, the phonons from the first mode will have their frequency upconverted to the same as the second mode’s phonons, thus allowing them to interact. This pump effectively amplifies the single phonon–phonon coupling rate of the mode

• role of the cavity mode in cavity optomechanics, respectively. Xi and Xj are their respective amplitudes, is the amplitude of the pump in meters, is the directional single phonon–phonon parametric coupling rate in Hz/meters. The last term describes a small signal Vsense, proportional to the voltage

• couplings at the same time. Innumerable applications include those studied in optomechanics and electromechanics, as well as theoretical implementations yet to be seen in practice, all powered by phonon–phonon interactions. Not only bringing improvements to common AFM tools, but providing opportunities for

Enhanced electronic transport properties of Te roll-like nanostructures

• E. R. Viana,
• N. Cifuentes and
• J. C. González

Beilstein J. Nanotechnol. 2022, 13, 1284–1291, doi:10.3762/bjnano.13.106

• cm2/Vs at 5 K. The thermal ionization of shallow acceptors, with small ionization energy between 2 and 4 meV, leads to free-hole conduction at high temperatures. The free-hole mobility follows a negative power-law temperature behavior, with an exponent between −1.28 and −1.42, indicating strong phonon

• the mobility is mainly limited by phonon scattering at high temperatures, α is close to 3/2 [33][34]. Nveff is the effective density of states of the valence band, EA is the shallow acceptor ionization energy [33], and kB is Boltzmann’s constant. At lower temperatures, most of the free holes are

Analytical and numerical design of a hybrid Fabry–Perot plano-concave microcavity for hexagonal boron nitride

• Felipe Ortiz-Huerta and
• Karina Garay-Palmett

Beilstein J. Nanotechnol. 2022, 13, 1030–1037, doi:10.3762/bjnano.13.90

• our system (2D material + DBR stack) to have a maximum reflectivity at the center wavelength of 637 nm. The selected wavelength of our system falls within the typical emission rates of the zero-phonon line (ZPL) of SPEs in hBN (500–800 nm). A quarter-wavelength thickness is conveniently chosen for the

Numerical study on all-optical modulation characteristics of quantum cascade lasers

• Biao Wei,
• Haijun Zhou,
• Guangxiang Li and
• Bin Tang

Beilstein J. Nanotechnol. 2022, 13, 1011–1019, doi:10.3762/bjnano.13.88

• standard 35-stage In0.52Al0.48As/In0.53Ga0.47As type-I four-level Fabry–Perot QCL based on a two-phonon-resonance design [27]. Current injection efficiency is defined as the ratio of current to total current injected into the upper subband of the QCL in the active region, which is close to 56%. The QCL

Efficiency of electron cooling in cold-electron bolometers with traps

• Dmitrii A. Pimanov,
• Vladimir A. Frost,
• Anton V. Blagodatkin,
• Anna V. Gordeeva,
• Andrey L. Pankratov and
• Leonid S. Kuzmin

Beilstein J. Nanotechnol. 2022, 13, 896–901, doi:10.3762/bjnano.13.80

• superconductor/ferromagnet hybrid absorbers based on Al/Fe films, as the previous samples. However, there are different oxidation parameters. This work aims to improve our new fit methodology, which takes into account both leakage and Andreev currents and also uses the sixth power of phonon and electron

• solves the equations of the stationary CEB theory [16]. We use the approach based on solving the heat balance equation [7]: where PN is Joule heating in the absorber. is the heat flux between electron and phonon subsystems, taken with the sixth power [17] due to low electron temperature in our

• experiments (in our previous calculations we have used the fifth power). Σ is the electron–phonon coupling constant; it has different values, depending on the electron temperature [17]. VN is the absorber volume, Pcool is the direct electron cooling power, PS is the net power transferred to the S-electrode

Numerical modeling of a multi-frequency receiving system based on an array of dipole antennas for LSPE-SWIPE

• Alexander V. Chiginev,
• Anton V. Blagodatkin,
• Dmitrii A. Pimanov,
• Ekaterina A. Matrozova,
• Anna V. Gordeeva,
• Andrey L. Pankratov and
• Leonid S. Kuzmin

Beilstein J. Nanotechnol. 2022, 13, 865–872, doi:10.3762/bjnano.13.77

• electronic subsystem of the CEB absorber [6][7][8]. Another key advantage for balloon and space missions is the high immunity of CEB against cosmic rays [9] due to a double protection given by the extremely small volume of the absorber and decoupling of electron and phonon systems. One of the advantages of

Optimizing PMMA solutions to suppress contamination in the transfer of CVD graphene for batch production

• Chun-Da Liao,
• Andrea Capasso,
• Tiago Queirós,
• Telma Domingues,
• Fatima Cerqueira,
• Nicoleta Nicoara,
• Jérôme Borme,
• Paulo Freitas and
• Pedro Alpuim

Beilstein J. Nanotechnol. 2022, 13, 796–806, doi:10.3762/bjnano.13.70

• ± 3.0 cm−1 (Figure 2f,i), implying high-quality monolayer graphene. Together, the data further support uniformity and crystallinity of the sample. The G phonon band arises from double degeneracy of iTO and iLO phonon modes (E2g symmetry) at the Brillouin zone center, which is an in-plane vibration of

• the PMMA mixture, we consider that the differences in Raman spectra between the different samples can be attributed to adsorbed PMMA residues. Such residues could absorb water and oxygen molecules, conferring p-type doping to graphene [29]. Conversely, by tracking the G phonon band features in Raman

• ). The broader G phonon band observed for the B2 samples reveals that a significantly higher number of inter-band decay pathways are available due to a lower Pauli blocking threshold [23] (equivalent to twice |EF|), further indicating that the p-type doping caused by adsorbed PMMA is less intense for the

Efficient liquid exfoliation of KP₁₅ nanowires aided by Hansen's empirical theory

• Zhaoxuan Huang,
• Zhikang Jiang,
• Nan Tian,
• Disheng Yao,
• Fei Long,
• Yanhan Yang and
• Danmin Liu

Beilstein J. Nanotechnol. 2022, 13, 788–795, doi:10.3762/bjnano.13.69

• value below 100 nm. The thinnest KP15 nanowires reached 5.1 nm and had smooth boundaries. Meanwhile, strong temperature-dependent Raman response in exfoliated KP15 nanowires has been observed, which indicates a strong phonon–phonon coupling in those nanowires. This is helpful for non-invasive

• reached 5.1 nm and had smooth boundaries. Meanwhile, a strong temperature-dependent Raman response was found in exfoliated KP15 nanowires. This indicates a strong phonon–phonon coupling in KP15 nanowires, which favors non-invasive temperature measurements of KP15 nanodevices. Methods Synthesis of KP15

Experimental and theoretical study of field-dependent spin splitting at ferromagnetic insulator–superconductor interfaces

• Peter Machon,
• Michael J. Wolf,
• Detlef Beckmann and
• Wolfgang Belzig

Beilstein J. Nanotechnol. 2022, 13, 682–688, doi:10.3762/bjnano.13.60

• relation is given by: We defined the cutoff energy ΩBCS related to the upper limit of the phonon spectrum. In the following, we use ΩBCS = 100kBTc, and the coupling constant λ, which can be eliminated for the bulk superconductor in favor of the critical temperature Tc. After solving the fully self

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

• contribute actively to electron–phonon coupling [36]. With a face-on orientation of the CuPc molecules at the MoSe2 monolayer, the delocalized π electrons of CuPc overlap efficiently with the electron cloud of the MoSe2 monolayer. As the HOMO of CuPc is close to the valence band of the MoSe2 monolayer as

• , the electron transition probability can be increased by increasing the density of states, which plays a significant role in the ground-state charge-transfer process, further leading to an enhancement of electron–phonon coupling and, consequently, an increase of the Raman scattering intensity [39

Effect of lubricants on the rotational transmission between solid-state gears

• Huang-Hsiang Lin,
• Jonathan Heinze,
• Alexander Croy,
• Rafael Gutiérrez and
• Gianaurelio Cuniberti

Beilstein J. Nanotechnol. 2022, 13, 54–62, doi:10.3762/bjnano.13.3

• multiscale simulation involving continuum modelling in combination with MD simulations would be helpful to connect the atomistic description with macroscopic behavior, for example, as given by the Stribeck curve [5]. A substrate can also provide significant friction due to electron or phonon excitations [65

Plasmon-enhanced photoluminescence from TiO₂ and TeO₂ thin films doped by Eu³⁺ for optoelectronic applications

• Marcin Łapiński,
• Jakub Czubek,
• Katarzyna Drozdowska,
• Anna Synak,
• Wojciech Sadowski and
• Barbara Kościelska

Beilstein J. Nanotechnol. 2021, 12, 1271–1278, doi:10.3762/bjnano.12.94

• popular and widely used oxide material as matrix for rare-earth ions [9][10][11][12][13]. Tellurium dioxide can be also considered as excellent in hosting rare-earth ions because of its low phonon energy (ca. 700–800 cm−1), which allows to minimize non-radiative losses [14][15][16]. Modification of oxide

Impact of electron–phonon coupling on electron transport through T-shaped arrangements of quantum dots in the Kondo regime

• Patryk Florków and
• Stanisław Lipiński

Beilstein J. Nanotechnol. 2021, 12, 1209–1225, doi:10.3762/bjnano.12.89

• strength of electron–phonon interaction, the system is occupied by a different number of electrons that effectively interact with each other repulsively or attractively. This leads, together with the interference effects, to different spin or charge Fano–Kondo effects. Keywords: Fano effect; Kondo effect

• ultrafast sensors, actuators, and signal processing components. Of special interest are molecular systems because molecules due to their softness easily deform during tunneling processes, giving rise to excitation of local phonon modes. The polaronic transport through molecular systems has been recently

• studied in a number of papers [39][40][41][42][43][44]. Due to participation of localized phonons in single electron tunneling the phonon side bands appear in the spectral function of the dot. Interestingly, similar effects have been also observed in the rigid structures of semiconductor quantum dots

First-principles study of the structural, optoelectronic and thermophysical properties of the π-SnSe for thermoelectric applications

• Muhammad Atif Sattar,
• Najwa Al Bouzieh,
• Maamar Benkraouda and
• Noureddine Amrane

Beilstein J. Nanotechnol. 2021, 12, 1101–1114, doi:10.3762/bjnano.12.82

• from Figure 6a that for a fixed pressure, the CV curve grows sharply up to 300 K then the value of CV gradually raises. Afterward, at a higher temperature range, the CV curve keeps a continuing pace and tends to reach the Dulong–Petit limit, revealing that at a high-temperature range all the phonon

• large entropy impact which accelerates the phonon–phonon scattering process. The total thermal conductivity (κtot) for the π-SnSe alloy is also plotted and presented in Figure 9c. It can be noted that initially, by the increase in temperature, κtot decreases and reaches its minimum value of 1.089 W·m−1

A review of defect engineering, ion implantation, and nanofabrication using the helium ion microscope

• Frances I. Allen

Beilstein J. Nanotechnol. 2021, 12, 633–664, doi:10.3762/bjnano.12.52

• phonon scattering effect from the few point defects introduced. For higher doses above ca. 2 × 1016 ions/cm2, complete amorphization of the material occurred, although it was noted that the overall morphology of the structure was unaffected. This ability to locally tune the thermal conductivity by

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

• a deep understanding of the phenomena occurring on such interface. One of the most common experimental techniques for studying properties of graphene is Raman spectroscopy [10]. Non-invasive measurements of inelastic light scattering give an insight into the phonon structure of graphene. The

• of strain, and the value of 2D band energy for unstrained graphene was reported to be 2677.6 cm−1 [14]. Positive values of Δε correspond to tensile strain while negative values correspond to compressive strain. The Grüneisen parameter determines the change rate of a given phonon frequency in a

• equal to 1583.5 cm–1 [14]. The sensitivity of the G band energy on the carrier concentration is caused by the presence of a Kohn anomaly near the Γ point in the phonon band structure of graphene [15]. Consequently, the G band energy significantly increases with an increasing concentration of both