Evaluation of gas-sensing properties of ZnO nanostructures electrochemically doped with Au nanophases

• Elena Dilonardo,
• Michele Penza,
• Marco Alvisi,
• Cinzia Di Franco,
• Francesco Palmisano,
• Luisa Torsi and
• Nicola Cioffi

Beilstein J. Nanotechnol. 2016, 7, 22–31, doi:10.3762/bjnano.7.3

• operating temperature of the sensors [32], cycled temperature operation, and the use of nanotechnology. Among these, the use of dopants and/or catalytic elements has been considered an effective way to improve the sensor performance [33]. Specifically, the loading of MOS with noble metals (e.g., Au, Pt, and

• affects the ZnO morphology and crystallinity, the distribution of Au dopants on the ZnO nanostructures, and the chemical composition at the interface between the two systems; therefore, it should strongly influence the ZnO properties concerning the gas adsorption and reactivity, as discussed in the next

Large area scanning probe microscope in ultra-high vacuum demonstrated for electrostatic force measurements on high-voltage devices

• Urs Gysin,
• Thilo Glatzel,
• Thomas Schmölzer,
• Adolf Schöner,
• Sergey Reshanov,
• Holger Bartolf and
• Ernst Meyer

Beilstein J. Nanotechnol. 2015, 6, 2485–2497, doi:10.3762/bjnano.6.258

• (JBS) rectifier-architecture, where highly doped p+-regions are embedded into the active device area to shield the Schottky contact from high electric fields and to handle surge-current events at the same time [59][60]. The implantation of dopants as well as the electronic properties of these embedded

Kelvin probe force microscopy for local characterisation of active nanoelectronic devices

• Tino Wagner,
• Hannes Beyer,
• Patrick Reissner,
• Philipp Mensch,
• Heike Riel,
• Bernd Gotsmann and
• Andreas Stemmer

Beilstein J. Nanotechnol. 2015, 6, 2193–2206, doi:10.3762/bjnano.6.225

• electric field by adjusting a bias voltage between tip and sample. Hence, Kelvin probe force microscopy is able to quantify the local contact potential difference (CPD), Ulcpd, which contains contributions, e.g., from the difference in work function between the AFM tip and structures on the sample, dopants

Nanostructured superhydrophobic films synthesized by electrodeposition of fluorinated polyindoles

• Gabriela Ramos Chagas,
• Thierry Darmanin and
• Frédéric Guittard

Beilstein J. Nanotechnol. 2015, 6, 2078–2087, doi:10.3762/bjnano.6.212

• advantages such as an easiness to functionalize and opto-electronic properties [16] with the possibility to introduce various dopants (smart materials) [17][18]. Conducting polymers are also exceptional materials for the control of surface nanostructures and wettability. First of all, nanostructures of

Addition of Zn during the phosphine-based synthesis of indium phospide quantum dots: doping and surface passivation

• Natalia E. Mordvinova,
• Alexander A. Vinokurov,
• Oleg I. Lebedev,
• Tatiana A. Kuznetsova and
• Sergey G. Dorofeev

Beilstein J. Nanotechnol. 2015, 6, 1237–1246, doi:10.3762/bjnano.6.127

• that the doping of III–V QDs creates an opportunity to produce materials with new optical properties that vary depending on the dopant type. This opportunity has promoted the development of synthetic methods for incorporating dopants into InP QDs. There are some efforts focused on the incorporation of

• ionic radii of In3+ and Zn2+ have very close values (0.080 nm and 0.074 nm, respectively) [15]. Thus, Zn is one of the most important p-type dopants in volume InP. The presence of Zn in InP QDs is usually regarded in the context of being covered with ZnSe [16] or ZnS [17] shells, which drastically

Pt- and Pd-decorated MWCNTs for vapour and gas detection at room temperature

• Hamdi Baccar,
• Atef Thamri,
• Pierrick Clément,
• Eduard Llobet and
• Adnane Abdelghani

Beilstein J. Nanotechnol. 2015, 6, 919–927, doi:10.3762/bjnano.6.95

• electrons to pass easily between the metal nanoparticles and CNTs. The direction of the charge transfer depends on the composition of the surrounding gas. Furthermore, the electronegativity values for Pt and Pd are quite similar and so is the relative weight (in atom %) of the metal dopants in both types of

Morphology control of zinc oxide films via polysaccharide-mediated, low temperature, chemical bath deposition

• Florian Waltz,
• Hans-Christoph Schwarz,
• Andreas M. Schneider,
• Stefanie Eiden and
• Peter Behrens

Beilstein J. Nanotechnol. 2015, 6, 799–808, doi:10.3762/bjnano.6.83

• where highly conductive materials are required (e.g., solar cells and light emitting diodes (LEDs)), ZnO must be doped. Several groups have reported the successful doping of ZnO films with dopants such as magnesium [21], iodine [22], boron [23][24], titanium [25], manganese [26], and aluminium [27][28

Tm-doped TiO₂ and Tm₂Ti₂O₇ pyrochlore nanoparticles: enhancing the photocatalytic activity of rutile with a pyrochlore phase

• Desiré M. De los Santos,
• Javier Navas,
• Teresa Aguilar,
• Antonio Sánchez-Coronilla,
• Concha Fernández-Lorenzo,
• Rodrigo Alcántara,
• Jose Carlos Piñero,
• Ginesa Blanco and
• Joaquín Martín-Calleja

Beilstein J. Nanotechnol. 2015, 6, 605–616, doi:10.3762/bjnano.6.62

• [5]. TiO2 doping with metallic elements has also been reported, using for example niobium [6], silver [7] or copper [8] as dopants. Many pyrochlore-type compounds (A2B2O7) have been studied to evaluate their semiconductor properties for photocatalytic applications. For example, it is possible to find

Overview of nanoscale NEXAFS performed with soft X-ray microscopes

• Peter Guttmann and
• Carla Bittencourt

Beilstein J. Nanotechnol. 2015, 6, 595–604, doi:10.3762/bjnano.6.61

• NEXAFS-TXM. As a result of this investigation it was found that neither Cd nor S diffuse into the CuO phase after the deposition of CdS on the CuO nanowires [60][61]. The possibility to study the oxidation state of Mn dopants in titanate nanostructures was reported in [62]. Additionally, using the

Chains of carbon atoms: A vision or a new nanomaterial?

• Florian Banhart

Beilstein J. Nanotechnol. 2015, 6, 559–569, doi:10.3762/bjnano.6.58

• to electron localization. It is well known that the electrical properties of graphene depend strongly on adsorbed species that might even act as dopants. A similar influence of attached atoms or molecules might occur in carbon chains since their conductivity is also carried by the π-electron system

Synergic combination of the sol–gel method with dip coating for plasmonic devices

• Cristiana Figus,
• Maddalena Patrini,
• Francesco Floris,
• Lucia Fornasari,
• Paola Pellacani,
• Gerardo Marchesini,
• Andrea Valsesia,
• Flavia Artizzu,
• Daniela Marongiu,
• Michele Saba,
• Franco Marabelli,
• Andrea Mura,
• Giovanni Bongiovanni and
• Francesco Quochi

Beilstein J. Nanotechnol. 2015, 6, 500–507, doi:10.3762/bjnano.6.52

• sol–gel thin film behaved as a host matrix in which suitable vis or NIR fluorophore dopants could be dispersed. This is useful to couple the plasmonic and the emission signals, thus preventing undesirable metal-induced radiative emission quenching [17]. Finally, using organically modified alkoxides

Nanoporous Ge thin film production combining Ge sputtering and dopant implantation

• Jacques Perrin Toinin,
• Alain Portavoce,
• Khalid Hoummada,
• Michaël Texier,
• Maxime Bertoglio,
• Sandrine Bernardini,
• Marco Abbarchi and
• Lee Chow

Beilstein J. Nanotechnol. 2015, 6, 336–342, doi:10.3762/bjnano.6.32

• morphology of the Ge film at different process steps under different postannealing conditions. For the same postannealing conditions, the Ge film topology was shown to be similar for different implantation doses and different dopants. However, the film topology can be controlled by adjusting the

• of the Ge film up to a depth of 140 nm. One can observe in Figure 1 that no dopants and no vacancies are expected to be found at a depth larger than 220 nm. Consequently, the implantation-induced defects should be confined in the Ge layer thickness. Figure 2 presents scanning electron microscopy (SEM

• during annealing of implanted films. However, the structure obtained with the as-deposited Ge films (Figure 5.1) is quite different from the structure obtained with implanted films (Figure 3 and Figure 5.2). Consequently, the implantation process, and possibly the nature of the implanted dopants (Ge

Tunable white light emission by variation of composition and defects of electrospun Al₂O₃–SiO₂ nanofibers

• Jinyuan Zhou,
• Gengzhi Sun,
• Hao Zhao,
• Xiaojun Pan,
• Zhenxing Zhang,
• Yujun Fu,
• Yanzhe Mao and
• Erqing Xie

Beilstein J. Nanotechnol. 2015, 6, 313–320, doi:10.3762/bjnano.6.29

• that the blue light centers, such as O defects (420 nm), first slightly decrease with the increasing Al/(Al–Si) ratio, and then increase, and reach their minimum value at an Al content of 60 mol % with further increase in Al content. This result indicates that suitable dopants of Si or Al are

X-ray photoelectron spectroscopy of graphitic carbon nanomaterials doped with heteroatoms

• Toma Susi,
• Thomas Pichler and
• Paola Ayala

Beilstein J. Nanotechnol. 2015, 6, 177–192, doi:10.3762/bjnano.6.17

• distribution and bonding of heteroatom dopants in carbon nanomaterials such as graphene and carbon nanotubes. Although these materials have superb intrinsic properties, these often need to be modified in a controlled way for specific applications. Towards this aim, the most studied dopants are neighbors to

• carbon in the periodic table, nitrogen and boron, with phosphorus starting to emerge as an interesting new alternative. Hundreds of studies have used XPS for analyzing the concentration and bonding of dopants in various materials. Although the majority of works has concentrated on nitrogen, important

• in their properties or in the distribution of dopants poses additional challenges for characterization. Furthermore, although local methods such as scanning tunneling microscopy (STM) [24][25] and transmission electron microscopy based electron energy loss spectroscopy (TEM/EELS) [23][26] can these

Influence of stabilising agents and pH on the size of SnO₂ nanoparticles

• Olga Rac,
• Patrycja Suchorska-Woźniak,
• Marta Fiedot and
• Helena Teterycz

Beilstein J. Nanotechnol. 2014, 5, 2192–2201, doi:10.3762/bjnano.5.228

• of dopants. For this reason, the electrical properties of oxide nanomaterials strongly depend on the kinetics of the processes occurring on its surface, which is extremely important during operation of chemical gas sensors [7][8]. Although the number of publications on the synthesis of oxide

Carbon-based smart nanomaterials in biomedicine and neuroengineering

• Antonina M. Monaco and
• Michele Giugliano

Beilstein J. Nanotechnol. 2014, 5, 1849–1863, doi:10.3762/bjnano.5.196

• make them suitable for biological applications [14]. The optical properties of NDs are remarkable: highly pure diamond is fully transparent and colourless, whereas the presence of lattice impurities and dopants render diamond coloured [15]. When NDs are excited by UV light [16], they display

Electronic and electrochemical doping of graphene by surface adsorbates

• Hugo Pinto and
• Alexander Markevich

Beilstein J. Nanotechnol. 2014, 5, 1842–1848, doi:10.3762/bjnano.5.195

• atomic and molecular dopants. Review Mechanisms of doping Charge carriers, either electrons or holes, can be induced in graphene by the application of an electric field or by chemical doping. The electric field effect doping is usually performed in graphene-based field effect transistors (FET), in which

• , Figure 1b, act as donors and dope graphene n-type. Although surface transfer doping is an effective method to control the concentration of charge carriers in graphene the ionized dopants can act as an additional source of scattering for charge carriers and reduce their mobility. The electrochemical

• case the reaction or diffusion rates are slower than the rate of change of gate voltage electrochemical doping can lead to hysteresis effects which are often observed in graphene-based FET devices [21][22][23][24]. Electronic dopants The ability to dope graphene either n- or p-type has been

Silicon and germanium nanocrystals: properties and characterization

• Ivana Capan,
• Alexandra Carvalho and
• José Coutinho

Beilstein J. Nanotechnol. 2014, 5, 1787–1794, doi:10.3762/bjnano.5.189

• each other, and one-particle calculations actually give accurate values for the excitonic gap(s). III.2.2 Doping of Si nanocrystals: The deliberate introduction of dopants into materials lies at the heart of microelectronics. A prototypical example is the replacement of a few lattice sites in a billion

• applications of Si NCs rely on the possibility to tune their electronic states by exploring surface effects, the fact is that this is only possible in ultra-small NCs in which effective electrical doping, which leads to a spontaneous ionization of dopants at room-temperature, is yet to be demonstrated

• . Notwithstanding, the introduction of dopants in Si NCs has been unequivocally demonstrated, for instance by monitoring the 31P hyperfine splitting of the phosphorous donor state during electron paramagnetic resonance experiments [56], or from photoluminescent transitions of bound excitons to boron [57]. In small

Numerical investigation of the effect of substrate surface roughness on the performance of zigzag graphene nanoribbon field effect transistors symmetrically doped with BN

• Majid Sanaeepur,
• Arash Yazdanpanah Goharrizi and
• Mohammad Javad Sharifi

Beilstein J. Nanotechnol. 2014, 5, 1569–1574, doi:10.3762/bjnano.5.168

• tight-binding Hamiltonian. Because of the statistical nature of SR an ensemble average is taken over a large number of devices to obtain averaged device characteristics. Model and Methods The sp2 hybridization of carbon atoms in the GNR lattice is preserved in the presence of B or N dopants [34

• of Figure 2a shows that by increasing the roughness amplitude from 100 to 350 pm, the BN-doping induced transport gap decreases from 1.19 to 0.99 eV due to decreased average hopping between edge atoms of ZGNR and BN dopants. The average transmission of a 10 nm length 4h-2BN-ZGNR with 200 pm SR

• , ZGNRFETs can meet the required on/off-current ratio for future digital electronics. Top view of a 5h-2BN-ZGNR (left panel) and the same GNR with surface roughness (right panel). The blue circles represent carbon atoms while boron and nitrogen dopants are shown in green and red, respectively. (a) Averaged

Effects of palladium on the optical and hydrogen sensing characteristics of Pd-doped ZnO nanoparticles

• Anh-Thu Thi Do,
• Hong Thai Giang,
• Thu Thi Do,
• Ngan Quang Pham and
• Giang Truong Ho

Beilstein J. Nanotechnol. 2014, 5, 1261–1267, doi:10.3762/bjnano.5.140

• ], compatibility with other nanodevices, and are potentially the best gas sensors. Oxides cannot easily distinguish between different types of gases, but the addition of certain noble metals as dopants can promote the gas-sensing performance [9][10][11]. Noble metal dopants in ZnO can modify the optical and

Sublattice asymmetry of impurity doping in graphene: A review

• James A. Lawlor and
• Mauro S. Ferreira

Beilstein J. Nanotechnol. 2014, 5, 1210–1217, doi:10.3762/bjnano.5.133

• graphene, with a focus on substitutional nitrogen dopants. It is well known that one current limitation of graphene in regards to its use in electronics is that in its ordinary state it exhibits no band gap. By doping one of its two sublattices preferentially it is possible to not only open such a gap

• semiconductor technology, which is characterised by a current on/off ratio of roughly 104–107 and a band gap of at least 340 meV whilst maintaining high carrier mobility [5][13][14]. Alteration of the crystal structure through the introduction of foreign dopants is one of the more realistic avenues of approach

• in realising this goal. Atomic dopants like boron (B) or nitrogen (N) are a similar size to carbon and can be introduced easily in a variety of graphene growth processes, typically replacing carbon sites and forming substitutional impurities in the lattice, positively (p-) and negatively (n-) doping

Highly NO₂ sensitive caesium doped graphene oxide conductometric sensors

• Carlo Piloto,
• Marco Notarianni,
• Mahnaz Shafiei,
• Elena Taran,
• Dilini Galpaya,
• Cheng Yan and
• Nunzio Motta

Beilstein J. Nanotechnol. 2014, 5, 1073–1081, doi:10.3762/bjnano.5.120

• and environmental monitoring [12]. Theoretical [13][14] and experimental [15][16][17][18][19] studies have revealed that functionalization of graphene can improve significantly its gas sensing performance [20]. The presence of dopants or defects in the graphene lattice can increase the adsorption

• of oxygen groups. However, the sensor shows very long recovery, making GO-Cs a good candidate for applications requiring high sensitivities, but not fast response. Future works will focus on investigating the effect of different species and concentration of dopants on improving the selectivity

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

• drain, respectively. A scanning electron microscope (SEM) image of the device is shown in Figure 5. The source and drain regions are heavily doped with boron, while the nanowire channel has a low-doping concentration of phosphorous. The contacts were doped by different dopants in order to form an off

Resonance of graphene nanoribbons doped with nitrogen and boron: a molecular dynamics study

• Ye Wei,
• Haifei Zhan,
• Kang Xia,
• Wendong Zhang,
• Shengbo Sang and
• Yuantong Gu

Beilstein J. Nanotechnol. 2014, 5, 717–725, doi:10.3762/bjnano.5.84

• discussed. A systematic study of the vibrational properties of graphene doped with nitrogen and boron is performed by means of a molecular dynamics simulation. The influence from different density or species of dopants has been assessed. It is found that the impacts on the quality factor, Q, resulting from

• different densities of dopants vary greatly, while the influence on the resonance frequency is insignificant. The reduction of the resonance frequency caused by doping with boron only is larger than the reduction caused by doping with both boron and nitrogen. This study gives a fundamental understanding of

• the resonance of graphene with different dopants, which may benefit their application as resonators. Keywords: dopant; graphene; molecular dynamics simulation; natural frequency; quality factor; resonance; Introduction Graphene has drawn intensive interest since its discovery in 2005 [1]. It has

Towards precise defect control in layered oxide structures by using oxide molecular beam epitaxy

• Federico Baiutti,
• Georg Christiani and
• Gennady Logvenov

Beilstein J. Nanotechnol. 2014, 5, 596–602, doi:10.3762/bjnano.5.70

• sequence of the atomic layers. In semiconductors MBE, the ALL-MBE method is used to deposit so called “delta doped” structures [18], where the dopants are confined to a single atomic plane. Extending this approach to the field of oxide MBE, one can do “single atomic layer engineering”, precisely defining