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

• electronics and optical devices [6][7]. The controlled growth of single crystalline 1D semiconductor nanostructures (NSs) of various dimensionality with desired chemical composition and precise doping level has offered numerous possibilities for making model devices and integration strategies [6][8

Study of silica-based intrinsically emitting nanoparticles produced by an excimer laser

• Imène Reghioua,
• Mattia Fanetti,
• Sylvain Girard,
• Diego Di Francesca,
• Simonpietro Agnello,
• Layla Martin-Samos,
• Marco Cannas,
• Matjaz Valant,
• Melanie Raine,
• Marc Gaillardin,
• Nicolas Richard,
• Philippe Paillet,
• Aziz Boukenter,
• Youcef Ouerdane and
• Antonino Alessi

Beilstein J. Nanotechnol. 2019, 10, 211–221, doi:10.3762/bjnano.10.19

• , pure silica nanoparticles were produced using a laser pulse energy of 400 mJ on pure silica, whereas Ge-doped nanoparticles were obtained using 33 and 165 mJ per pulse on germanosilicate glass. The difference in the required energy is attributed to the Ge doping, which modifies the optical properties

• low and/or the pulse duration is on the time scale of nanoseconds or longer. The second type of process is responsible for the absorption in transparent medium and is usually active for ultrashort laser pulses characterized by high intensity [14]. It is noteworthy that defects in or doping of a

• fragmentation [4]. Different from other studies [15][20], the purpose of the present investigation is to provide data concerning the production of pure and Ge-doped silica nanoparticles; thus it is worth highlighting some of the effects of the Ge doping of silica. Indeed, the Ge atoms are substitutional to Si

Wet chemistry route for the decoration of carbon nanotubes with iron oxide nanoparticles for gas sensing

• Hussam M. Elnabawy,
• Juan Casanova-Chafer,
• Badawi Anis,
• Mostafa Fedawy,
• Mattia Scardamaglia,
• Carla Bittencourt,
• Ahmed S. G. Khalil,
• Eduard Llobet and
• Xavier Vilanova

Beilstein J. Nanotechnol. 2019, 10, 105–118, doi:10.3762/bjnano.10.10

• with iron oxide nanoparticles substantially ameliorated the response towards nitrogen dioxide. Keywords: benzene detection; doping; gas sensor; metal nanoparticle decoration; multiwalled carbon nanotubes; NO2 detection; room temperature gas sensing; surface modification; Introduction Carbon nanotubes

• results for carbon nanotubes decorated with iron oxide nanoparticles of larger size. This is consistent with the literature, in which heat treatment on sensors doped with an optimum doping ratio can cause both an increase in the size of decorating nanoparticles and an enhancement in the response of the

Threshold voltage decrease in a thermotropic nematic liquid crystal doped with graphene oxide flakes

• Mateusz Mrukiewicz,
• Krystian Kowiorski,
• Paweł Perkowski,
• Rafał Mazur and
• Małgorzata Djas

Beilstein J. Nanotechnol. 2019, 10, 71–78, doi:10.3762/bjnano.10.7

• -optical performance is doping them with nanoparticles. Hsu et al. showed that the small addition of gold nanoparticles decreases Uth due to the increased electric anisotropy and decreased elastic constant [5]. Haraguchi and collaborators doped the twisted nematic liquid crystal cell with inorganic

Amorphous Ni_xCo_yP-supported TiO₂ nanotube arrays as an efficient hydrogen evolution reaction electrocatalyst in acidic solution

• Yong Li,
• Peng Yang,
• Bin Wang and
• Zhongqing Liu

Beilstein J. Nanotechnol. 2019, 10, 62–70, doi:10.3762/bjnano.10.6

• −), suggesting a small electron density transfer from Ni and Co to P [37]. This charged structure is very beneficial for improving surface activity toward HER. A critical means to improve the charge transfer of HER is to enhance the conductivity of the electrocatalysts. Doping or hybridization to form a

• , respectively. It should be noted that the hydrogen doping may occur due to the small radius of the hydrogen atom when measuring the electrocatalytic activity of NixCoyP/TNAs. Generally speaking, hydrogen doping increases electrical conductivity and enhances electron transfer. Thus the electrocatalytic activity

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

• content and crystallite size. The fluorine presence is due to the catalytic partial decomposition of the SF6 laser energy transfer agent. In direct correlation with the increase in the Zn doping level, the bandgap of co-doped nanoparticles shifts to lower energy (from 3.55 to 2.88 eV for the highest Zn

• reduced bandgap of tin oxide nanoparticles by introduction of defects to the crystal lattice is ≈0.7 eV [4]. Generally, the doping of these semiconducting oxides with specific cations or anions is performed in order to increase their electrical conductivity while maintaining a high optical transparency in

• promising, lower cost, but good performing material alternatives to ITO for these types of applications is fluorine-doped tin oxide (FTO) [8]. Regarding the cation doping for the synthesis of tin-based transparent and conductive oxidic (TCO) materials, the literature has been focused on doping with i

Ternary nanocomposites of reduced graphene oxide, polyaniline and hexaniobate: hierarchical architecture and high polaron formation

• Claudio H. B. Silva,
• Maria Iliut,
• Christopher Muryn,
• Christian Berger,
• Zachary Coldrick,
• Vera R. L. Constantino,
• Marcia L. A. Temperini and
• Aravind Vijayaraghavan

Beilstein J. Nanotechnol. 2018, 9, 2936–2946, doi:10.3762/bjnano.9.272

• room temperature. Detailed characterisation by X-ray photoelectron and Raman spectroscopies indicates an intermediate reduction degree for the rGO component and high doping degree of the PANI chains compared to the neat polymer. The latter feature can be attributed to cooperative effects of PANI chains

• with rGO flakes and hexNb nanoscrolls, which promote conformational changes of the polymer backbone (secondary doping). Spectroscopic and electrochemistry data indicate a synergetic effect on the ternary nanocomposite, which is attributed to interactions between the components resulting from the

• morphological aspects. Therefore, the new nanocomposite presents promising properties for development of new materials in the film form on substrates for sensing or corrosion protection for example. Keywords: graphene oxide; hexaniobate; polyaniline; Raman spectroscopy; secondary doping; Introduction

Graphene-enhanced metal oxide gas sensors at room temperature: a review

• Dongjin Sun,
• Yifan Luo,
• Marc Debliquy and
• Chao Zhang

Beilstein J. Nanotechnol. 2018, 9, 2832–2844, doi:10.3762/bjnano.9.264

• heterojunctions are responsible for the exceptional NO2 sensing performance of CeO2–rGO sensor. Zhang et al. [59] added GO suspension to a Fe(NO3)3·9H2O solution, then synthesized α-Fe2O3–rGO hybrids via hydrothermal method. During the process of testing, the authors found that the doping amount of graphene

• significantly affected the sensing properties of the α-Fe2O3–rGO sensor. The α-Fe2O3–rGO sensor with the optimal doping amount of 12.2% showed the highest sensitivity and rapid response time to NO2 at room temperature. In addition, the sensor exhibited excellent selectivity to NO2 because other interference

• demonstrated that the response and recovery of this sensor were much faster than that of SnO2–rGO sensor, which could only work at 50–55 °C. The doping of Ag nanoparticles not only improved the electron transfer rate of the sensor, but also increased the number of active sites on the surface of the sensor

Variation of the photoluminescence spectrum of InAs/GaAs heterostructures grown by ion-beam deposition

• Alexander S. Pashchenko,
• Leonid S. Lunin,
• Eleonora M. Danilina and
• Sergei N. Chebotarev

Beilstein J. Nanotechnol. 2018, 9, 2794–2801, doi:10.3762/bjnano.9.261

• their isovalent doping with bismuth on the photoluminescence properties of InAs/GaAs heterostructures. The experimental samples were grown by ion-beam deposition. We showed that using three vertically stacked layers of InAs quantum dots separated by thin GaAs barrier layers was accompanied by a red

• -shift of the photoluminescence peak of InAs/GaAs heterostructures. An increase in the thickness of the GaAs barrier layers was accompanied by a blue shift of the photoluminescence peak. The effect of isovalent Bi doping of the GaAs barrier layers on the structural and optical properties of the InAs/GaAs

• . It is shown that isovalent doping of GaAs potential barriers by bismuth was accompanied by a red-shift of the photoluminescence peak of InAs quantum dots of 121 meV. Keywords: infrared photodetectors; ion-beam deposition; nanoheterostructures; photoluminescence; quantum dot; semiconductors

Near-infrared light harvesting of upconverting NaYF₄:Yb³⁺/Er³⁺-based amorphous silicon solar cells investigated by an optical filter

• Daiming Liu,
• Qingkang Wang and
• Qing Wang

Beilstein J. Nanotechnol. 2018, 9, 2788–2793, doi:10.3762/bjnano.9.260

• phase transition is completed after 12 h. In Figure 1c, energy-dispersive X-ray (EDX) analysis confirms the doping with Yb and Er. The molar ratio of Y/Yb/Er in the hexagonal phase NaYF4:Yb3+/Er3+ was determined to be 79.8:18.2:2. It is extremely close to the stoichiometric ratio of 80:18:2 of the most

Oriented zinc oxide nanorods: A novel saturable absorber for lasers in the near-infrared

• Pavel Loiko,
• Tanujjal Bora,
• Josep Maria Serres,
• Haohai Yu,
• Magdalena Aguiló,
• Francesc Díaz,
• Uwe Griebner,
• Valentin Petrov,
• Xavier Mateos and
• Joydeep Dutta

Beilstein J. Nanotechnol. 2018, 9, 2730–2740, doi:10.3762/bjnano.9.255

• under ns-laser excitation [23]. This effect was ascribed to the defects promoted by the Mn2+ doping. Some studies revealed reverse saturable absorption (optical limiting) in ZnO thin films and NRs [24]. Zhu et al. studied ultrafast saturable absorption of multiwalled carbon nanotubes (MWCNTs) on quartz

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

• . Here we explore doping in the very-low-density limit such that electrons can be bound to single donor atoms and pairs of donor atoms in a 2D environment in the context of quantum computation. This manuscript is organized as follows: In the following section, we give general arguments to estimate

• modulation of ionization energy has been studied in the context of achieving p-type/n-type doping for transistor-like devices, but it certainly remains relevant for the donor quantum manipulation proposed here. Another important issue to take into account is the fact that in 2D systems the dielectric

Polarization-dependent strong coupling between silver nanorods and photochromic molecules

• Gwénaëlle Lamri,
• Alessandro Veltri,
• Jean Aubard,
• Pierre-Michel Adam,
• Nordin Felidj and
• Anne-Laure Baudrion

Beilstein J. Nanotechnol. 2018, 9, 2657–2664, doi:10.3762/bjnano.9.247

• change in the refractive index or the doping ability of these materials allows the plasmonic system’s environment to be actively changed and the plasmonic properties to be controlled. Another way to control LSPR is to use photochromic molecules. These molecules can switch their conformation from a

Impact of the anodization time on the photocatalytic activity of TiO₂ nanotubes

• Jesús A. Díaz-Real,
• Geyla C. Dubed-Bandomo,
• Juan Galindo-de-la-Rosa,
• Luis G. Arriaga,
• Janet Ledesma-García and
• Nicolas Alonso-Vante

Beilstein J. Nanotechnol. 2018, 9, 2628–2643, doi:10.3762/bjnano.9.244

• photooxidation of methylene blue. Keywords: fluorine doping; nanotubes; photocatalytic activity; photoelectrochemistry; titanium(IV) oxide (TiO2); Introduction TiO2 started to attract great interest after Fujishima and Honda reported [1] on its photoelectrochemical (PEC) properties in 1972. Numerous features

• ] observed that a water-based electrolyte containing NH4F induced a co-doping with F and N in the TNTs. Their study suggested that a combination of applied potential and annealing temperature were responsible for the high photocatalytic activity (PCA) of their materials in the oxidation of methyl orange. In

• is supported by the fact that atomic radii for O (48 pm) and F (42 pm) are similar enough to allow for the replacement of the former, effectively doping the material by creating oxygen vacancies and different energy states [29]. XPS To characterize the surface chemistry, high-resolution XPS

Improved catalytic combustion of methane using CuO nanobelts with predominantly (001) surfaces

• Qingquan Kong,
• Yichun Yin,
• Bing Xue,
• Yonggang Jin,
• Wei Feng,
• Zhi-Gang Chen,
• Shi Su and
• Chenghua Sun

Beilstein J. Nanotechnol. 2018, 9, 2526–2532, doi:10.3762/bjnano.9.235

• by Hu et al. [22] and Jin et al. [28]. According to this understanding, the catalysis performance may be further improved by adding alloy elements or surface doping to reduce the barrier. Conclusion In summary, Cu(001) was identified as being the most promising among six low-index surfaces tested for

Thickness-dependent photoelectrochemical properties of a semitransparent Co₃O₄ photocathode

• Malkeshkumar Patel and
• Joondong Kim

Beilstein J. Nanotechnol. 2018, 9, 2432–2442, doi:10.3762/bjnano.9.228

• respect to the water redox potential [3][9][10]. The spinel Co3O4 is interesting because of its dual bandgap (1.5 and 2.2 eV), high absorption coefficient, intrinsic p-type doping and chemical stability. It has found application as a light-absorbing entity in all-metal-oxide photovoltaic cells [11][12][13

SERS active Ag–SiO₂ nanoparticles obtained by laser ablation of silver in colloidal silica

• Cristina Gellini,
• Francesco Muniz-Miranda,
• Alfonso Pedone and
• Maurizio Muniz-Miranda

Beilstein J. Nanotechnol. 2018, 9, 2396–2404, doi:10.3762/bjnano.9.224

• calculations, can also explain the SERS effect obtained by NIR excitation, even if the excitation radiation does not match the plasmonic band of the silver nanoparticles. In conclusion, a simple method is proposed to obtain Ag-doping of silica colloidal nanoparticles, avoiding complicated procedures and

Hierarchical heterostructures of Bi₂MoO₆ microflowers decorated with Ag₂CO₃ nanoparticles for efficient visible-light-driven photocatalytic removal of toxic pollutants

• Shijie Li,
• Wei Jiang,
• Shiwei Hu,
• Yu Liu,
• Yanping Liu,
• Kaibing Xu and
• Jianshe Liu

Beilstein J. Nanotechnol. 2018, 9, 2297–2305, doi:10.3762/bjnano.9.214

• obstacle, various methods have been developed, including doping [20][21] and the construction of heterojunctions [22][23][24][25][26][27][28][29][30][31][32][33]. Particularly, the combination of Bi2MoO6 with other semiconductors to construct heterojunction photocatalysts leads to an enhanced activity of

Intrinsic ultrasmall nanoscale silicon turns n-/p-type with SiO₂/Si₃N₄-coating

• Dirk König,
• Daniel Hiller,
• Noël Wilck,
• Birger Berghoff,
• Merlin Müller,
• Sangeeta Thakur,
• Giovanni Di Santo,
• Luca Petaccia,
• Joachim Mayer,
• Sean Smith and
• Joachim Knoch

Beilstein J. Nanotechnol. 2018, 9, 2255–2264, doi:10.3762/bjnano.9.210

• Aachen University, 52074, Germany Elettra Sincrotrone Trieste, Strada Statale 14 km 163.5, 34149 Trieste, Italy National Compute Infrastructure (NCI), The Australian National University, ACT 2601, Australia 10.3762/bjnano.9.210 Abstract Impurity doping of ultrasmall nanoscale (usn) silicon (Si

• doping to fail for Si nano-crystals (NCs) showing quantum confinement. To introduce electron- (n-) or hole- (p-) type conductivity, usn-Si may not require doping, but an energy shift of electronic states with respect to the vacuum energy between different regions of usn-Si. We show in theory and

• doping for ULSI, provide new opportunities for ultralow power electronics and open a whole new vista on the introduction of p- and n-type conductivity into usn-Si. Keywords: energy offset; impurity doping alternative; ultrasmall nanoscale silicon crystals; wires and devices; Introduction Impurity

Lead-free hybrid perovskites for photovoltaics

• Oleksandr Stroyuk

Beilstein J. Nanotechnol. 2018, 9, 2209–2235, doi:10.3762/bjnano.9.207

• this material as compared to planar films of the same composition [122]. It was found that of the three “homologs” of CsSnX3 HPs (X = Cl, Br, I) the bromide-based compound shows an exceptionally high photochemical and chemical stability, which can further be enhanced by doping with SnF2 [110]. The

• stability of MASnI3-based cells can also be strongly enhanced by doping with SnF2 [118][123][124]. The doped materials showed a remarkable stability when illuminated under ambient air conditions without additional encapsulation (Figure 4c). Additionally, the SnF2 doping results in a decrease of the HP

• bandgap down to 1.25 eV, which is highly beneficial for the cell performance. This redshift effect was attributed to the Burstein–Moss effect arising from a significant doping of the absorber material with holes [118]. The SnF2 doping was found to almost double the radiative lifetime of charge carriers

Electrospun one-dimensional nanostructures: a new horizon for gas sensing materials

• Muhammad Imran,
• Nunzio Motta and
• Mahnaz Shafiei

Beilstein J. Nanotechnol. 2018, 9, 2128–2170, doi:10.3762/bjnano.9.202

• and/or calcination temperature [130]. The most effective approach to improve the gas sensing response of pure MOx 1D nanostructures is by functionalizing with different catalytic metals, MOx or noble metals [11][146]. Doping changes the reaction kinetics and electronic characteristics as well as the

• electronic sensitization. Traditionally, the doping is done by noble metals like Au [109][146][153][154][155][156], Ag [157][158][159][160][161], Pt [162][163][164][165][166][167][168], or Pd [75][107][148][169][170][171][172][173][174][175][176]. Moreover, noble metals can catalyse the gas sensing response

• ]. Doping with Ae metals exhibits an advantage in grain growth control [86]. For example, after thermal treatment, nanoparticle/nanograins show necked connections for each type of Ae-doped SnO2 NF. Therefore, a conduction channel can be established within each aggregate due to the space-charge layer region

Phosphorus monolayer doping (MLD) of silicon on insulator (SOI) substrates

• Noel Kennedy,
• Ray Duffy,
• Luke Eaton,
• Dan O’Connell,
• Scott Monaghan,
• Shane Garvey,
• James Connolly,
• Chris Hatem,
• Justin D. Holmes and
• Brenda Long

Beilstein J. Nanotechnol. 2018, 9, 2106–2113, doi:10.3762/bjnano.9.199

• Applied Materials, Gloucester, Massachusetts, USA CRANN@AMBER, Trinity College Dublin, Dublin 2, Ireland 10.3762/bjnano.9.199 Abstract This paper details the application of phosphorus monolayer doping of silicon on insulator substrates. There have been no previous publications dedicated to the topic of

• MLD on SOI, which allows for the impact of reduced substrate dimensions to be probed. The doping was done through functionalization of the substrates with chemically bound allyldiphenylphosphine dopant molecules. Following functionalization, the samples were capped and annealed to enable the diffusion

• of dopant atoms into the substrate and their activation. Electrical and material characterisation was carried out to determine the impact of MLD on surface quality and activation results produced by the process. MLD has proven to be highly applicable to SOI substrates producing doping levels in

Metal-free catalysis based on nitrogen-doped carbon nanomaterials: a photoelectron spectroscopy point of view

• Mattia Scardamaglia and
• Carla Bittencourt

Beilstein J. Nanotechnol. 2018, 9, 2015–2031, doi:10.3762/bjnano.9.191

• have addressed in the last decades are described, in particular the enduring debate on the role of the different nitrogen functionalities in the catalytic activity of nitrogen-doped carbon nanotubes and graphene. Keywords: catalysis; carbon nanotubes; graphene; metal-free; nitrogen doping

• system. The most common nitrogen doping techniques and how the doping activates the surface are described, and the spectroscopic differences regarding the nitrogen incorporation in graphene and CNTs are discussed. Review Heteroatom-doped carbon nanostructures Carbon nanotubes and graphene share many

• zero-gap semiconductor). This peculiarity represents one of the biggest challenges for its use in concrete applications, because it results in a very low density of states (DOS) at the Fermi level for typical doping levels, making graphene an intrinsically inert material. To overcome these issues

A differential Hall effect measurement method with sub-nanometre resolution for active dopant concentration profiling in ultrathin doped Si_1−xGe_x and Si layers

• Richard Daubriac,
• Emmanuel Scheid,
• Hiba Rizk,
• Richard Monflier,
• Sylvain Joblot,
• Rémi Beneyton,
• Pablo Acosta Alba,
• Sébastien Kerdilès and
• Filadelfo Cristiano

Beilstein J. Nanotechnol. 2018, 9, 1926–1939, doi:10.3762/bjnano.9.184

• %. Scattering correction must be accounted for when extracting Hall effect parameters. The measured values of Hall carrier concentration and Hall mobility are therefore corrected by using the Hall scattering factor, rH, [33][34][35] which depends on the studied material, i.e., on Ge content, doping type and

• -uniform doping profiles, the depletion width (and the related correction) will vary with depth. For example, in the particular case discussed in this section, the investigated 20 nm thick SiGe layer is uniformly doped at 1019 cm−3. For typical silicon-dioxide charge densities of 1012 cm−2·eV−1, simple

• calculations provide a depletion width of about 2 nm. Consequently, in this case, a depth-scale translation is necessary. However, for the higher carrier concentrations typically investigated in source/drain doping studies, such as those discussed in the next section (1020 cm−3 and above), and considering the

Nonlinear effect of carrier drift on the performance of an n-type ZnO nanowire nanogenerator by coupling piezoelectric effect and semiconduction

• Yuxing Liang,
• Shuaiqi Fan,
• Xuedong Chen and
• Yuantai Hu

Beilstein J. Nanotechnol. 2018, 9, 1917–1925, doi:10.3762/bjnano.9.183

• center of the forbidden band. Hence, the electric field E2 induced only by the piezoelectric characteristics is symmetrical with regard to the neutral axis, as shown in Figure 5. After n-type doping, the Fermi level moves upwards from the center of the forbidden band. The deformation-induced electric