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 the active layer, the molecule traps electrons from the active layer, increasing its conductivity, because this increases the concentration of holes, which act as main charge carriers. Comparing the behavior of pristine and decorated CNTs, one can clearly see that the decoration process leads to

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

• nanomaterials are irradiated with light of a certain wavelength, the valence electrons transition back to the conduction band. Most of the conduction band electrons fall back into the deep electron traps and nonradiative transitions take the form of quenching. Semiconductor QDs with relatively shallow surface

• electron traps and holes can easily capture electrons to the conduction band. At the same time, the transition radiation returns to the valence band, emitting a photon. The PL characteristics are, therefore, better than in materials which have deep traps in the bulk semiconductor material. This finding

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

• concentration of surface hydroxy groups is generally observed in doped TiO2 nanostructures, and these are indicated through the asymmetry of the O 1s spectra [32][36]. Ti–OH groups act as electron traps that not only improve the separation efficiency for electron–hole pairs, but also improve the generation of

• . While such behavior is still related to the length of the nanostructures, it could also be associated with an increased number of electron traps since the potential is high enough to overcome recombination [65]. The differences observed in the interfacial PEC behavior suggest that a link between the

Exploring the photoleakage current and photoinduced negative bias instability in amorphous InGaZnO thin-film transistors with various active layer thicknesses

• Dapeng Wang and
• Mamoru Furuta

Beilstein J. Nanotechnol. 2018, 9, 2573–2580, doi:10.3762/bjnano.9.239

• bulk traps because of the identical a-IGZO/GI interfaces. Figure 2a–d shows the variation in the transfer characteristics of a-IGZO TFTs with various TIGZO under monochromatic light irradiation at the excitation wavelengths of 400, 430, 460, 490, and 530 nm. The transfer characteristics measured in the

• though the photon energy is smaller than the band gap of IGZO. In terms of the a-IGZO material, the high-density electron traps exist at (EC − E) of over 2.7 eV [9], which affect the photoleakage current of a-IGZO TFTs. The total amount of trapped electrons increase with an increase in the TIGZO. The

• oxygen-related defects, such as oxygen vacancies (VO), may be the origin of high-density electron traps near the EV in a-IGZO TFTs, which occupy the region near the valence band maximum with an energy width of ≈1.5 eV [26][27]. Figure 3a–d shows the variation in the transfer characteristics of a-IGZO

Lead-free hybrid perovskites for photovoltaics

• Oleksandr Stroyuk

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

• suppressed lattice disorder of this HP results in a low density of traps and sub-bandgap states reflecting in a relatively small Eg–Voc loss of 0.45 eV [70]. The bandgap of alloyed FASnxPb1−xI3 HPs was found to vary in an unexpected way, that is, decreasing upon the introduction of Sn from ≈1.5 eV for MAPI

• ]. Calculations by the density functional theory (DFT) indicated that a partial substitution of Cs+ with Rb+ should considerably increase the stability of CsSnI3 [117]. To avoid a partial conversion of Sn2+ into Sn4+, the latter acting as charge carrier traps in ASnX3 HPs, it was suggested to deposit the

Spin-coated planar Sb₂S₃ hybrid solar cells approaching 5% efficiency

• Pascal Kaienburg,
• Benjamin Klingebiel and
• Thomas Kirchartz

Beilstein J. Nanotechnol. 2018, 9, 2114–2124, doi:10.3762/bjnano.9.200

• formation a short air exposure was shown to increase device performance but longer exposure times deteriorated the solar cell [45]. In another study post-sulfurization reduced the Sb2O3 content and thereby the concentration of deep traps which improved solar cell performance [6]. As an alternative to CBD

Localized photodeposition of catalysts using nanophotonic resonances in silicon photocathodes

• Evgenia Kontoleta,
• Sven H. C. Askes,
• Lai-Hung Lai and
• Erik C. Garnett

Beilstein J. Nanotechnol. 2018, 9, 2097–2105, doi:10.3762/bjnano.9.198

• with higher catalytic activity, leading to preferential deposition, or traps that capture carriers preventing deposition. Conclusion We show that the optical modes of silicon nanostructures can be used for lithography-free patterning of catalytic nanoparticles. Tuning of the photo-electrochemical

Numerical analysis of single-point spectroscopy curves used in photo-carrier dynamics measurements by Kelvin probe force microscopy under frequency-modulated excitation

• Pablo A. Fernández Garrillo,
• Benjamin Grévin and
• Łukasz Borowik

Beilstein J. Nanotechnol. 2018, 9, 1834–1843, doi:10.3762/bjnano.9.175

• the effective time needed for exciton generation, dissociation and carrier separation. On the other hand, in the case of some organic photovoltaic (OPV) samples, the SPV built-up time can be attributed to the effective time needed to fill lower energy states (traps). In a more general way, it can be

• dynamics are governing the SPV behavior of the sample, as it is the case for instance for OPV samples exhibiting a high density of low-energy states (traps). Nonetheless, we stress that even if the calculated photo-carrier lifetime values do not fully agree with those reported in [4], the ratio between the

Multimodal noncontact atomic force microscopy and Kelvin probe force microscopy investigations of organolead tribromide perovskite single crystals

• Yann Almadori,
• David Moerman,
• Jaume Llacer Martinez,
• Philippe Leclère and
• Benjamin Grévin

Beilstein J. Nanotechnol. 2018, 9, 1695–1704, doi:10.3762/bjnano.9.161

• the surface potential probed by KPFM. It is now clear that a complex interplay exists between the charge carrier populations, traps, and mobile ions. Despite all the progress made, interpreting the surface potential (SP) and surface photovoltage (SPV) contrasts recorded by KPFM on polycrystalline lead

Electro-optical interfacial effects on a graphene/π-conjugated organic semiconductor hybrid system

• Karolline A. S. Araujo,
• Luiz A. Cury,
• Matheus J. S. Matos,
• Thales F. D. Fernandes,
• Luiz G. Cançado and
• Bernardo R. A. Neves

Beilstein J. Nanotechnol. 2018, 9, 963–974, doi:10.3762/bjnano.9.90

• migration [28]. At low temperatures, the volume probed by an exciton is reduced, which reduces the interaction probability with nonradiative traps or defects, reflecting an increase in the emission efficiency of the organic compound [29]. Moreover, the increase in emission efficiency with decreasing

Noble metal-modified titania with visible-light activity for the decomposition of microorganisms

• Maya Endo,
• Zhishun Wei,
• Kunlei Wang,
• Baris Karabiyik,
• Kenta Yoshiiri,
• Paulina Rokicka,
• Bunsho Ohtani,
• Agata Markowska-Szczupak and
• Ewa Kowalska

Beilstein J. Nanotechnol. 2018, 9, 829–841, doi:10.3762/bjnano.9.77

• clusters were preferentially deposited on surface defects of the support [55]. Therefore, fine titania with a high number of defects (electron traps, ETs) induced the formation of fine and well-dispersed NMNPs on titania surface, as shown in Figure 1 (top). In contrast, titania with large crystals (low

Mechanistic insights into plasmonic photocatalysts in utilizing visible light

• Kah Hon Leong,
• Azrina Abd Aziz,
• Lan Ching Sim,
• Pichiah Saravanan,
• Min Jang and
• Detlef Bahnemann

Beilstein J. Nanotechnol. 2018, 9, 628–648, doi:10.3762/bjnano.9.59

• Au and Ag, conducting oxides and semiconductor nanomaterials possess lower carrier concentrations that are useful for their resonance in the NIR range [16]. For example, when coupled with Pd, copper chalcogenide (Cu7S4) utilizes NIR range photons through LSPR, and Pd traps the hot-holes for

Combined scanning probe electronic and thermal characterization of an indium arsenide nanowire

• Tino Wagner,
• Fabian Menges,
• Heike Riel,
• Bernd Gotsmann and
• Andreas Stemmer

Beilstein J. Nanotechnol. 2018, 9, 129–136, doi:10.3762/bjnano.9.15

• , we separate a bias-independent offset, , from the raw measurements. A good first-order approximation to this offset is the zero-bias profile, Ulcpd(x, I = 0) [26]. However, the offset can depend weakly also on bias, since the population and depletion of traps is bias-dependent [27]. Furthermore

Atomic layer deposition and properties of ZrO₂/Fe₂O₃ thin films

• Kristjan Kalam,
• Helina Seemen,
• Peeter Ritslaid,
• Mihkel Rähn,
• Aile Tamm,
• Kaupo Kukli,
• Aarne Kasikov,
• Joosep Link,
• Raivo Stern,
• Salvador Dueñas,
• Helena Castán and
• Héctor García

Beilstein J. Nanotechnol. 2018, 9, 119–128, doi:10.3762/bjnano.9.14

• layer under certain polarity, and an opposite polarity with increasing, oppositely directed field is required to release the charge from the traps for the subsequent drift towards the counterelectrode. The current density to applied electric field curves are shown in Figure 7 to support the given

Nematic topological defects positionally controlled by geometry and external fields

• Pavlo Kurioz,
• Marko Kralj,
• Bryce S. Murray,
• Charles Rosenblatt and
• Samo Kralj

Beilstein J. Nanotechnol. 2018, 9, 109–118, doi:10.3762/bjnano.9.13

• rotation of an assembly of TDs. Finally, we show that an external electric field could be used to drag the boojum fingertip towards the interior of the confinement cell. Assemblies of TDs could be exploited as traps for appropriate nanoparticles, opening several opportunities for the development of

Fabrication of CeO₂–MO_x (M = Cu, Co, Ni) composite yolk–shell nanospheres with enhanced catalytic properties for CO oxidation

• Ling Liu,
• Jingjing Shi,
• Hongxia Cao,
• Ruiyu Wang and
• Ziwu Liu

Beilstein J. Nanotechnol. 2017, 8, 2425–2437, doi:10.3762/bjnano.8.241

• [40]. Therefore, the molecular oxygen activation and extraction preferentially takes place at the interface site between MOx and CeO2. During CO oxidation over the CeO2–MOx catalyst, MOx provides chemisorption sites for CO molecules, while CeO2 traps oxygen molecules with oxygen vacancies and

Substrate and Mg doping effects in GaAs nanowires

• Perumal Kannappan,
• Nabiha Ben Sedrine,
• Jennifer P. Teixeira,
• Maria R. Soares,
• Bruno P. Falcão,
• Maria R. Correia,
• Nestor Cifuentes,
• Emilson R. Viana,
• Marcus V. B. Moreira,
• Geraldo M. Ribeiro,
• Alfredo G. de Oliveira,
• Juan C. González and
• Joaquim P. Leitão

Beilstein J. Nanotechnol. 2017, 8, 2126–2138, doi:10.3762/bjnano.8.212

• surface charge traps that induce a pinning of the Fermi level at the surface, especially for diameters below 100 nm [68]. However, if we compare the diameter of the three studied nanowires #1, #2 and #3, which were 190, 187 and 179 nm, respectively, the effect of surface scattering should be similar

High-stress study of bioinspired multifunctional PEDOT:PSS/nanoclay nanocomposites using AFM, SEM and numerical simulation

• Alfredo J. Diaz,
• Hanaul Noh,
• Tobias Meier and
• Santiago D. Solares

Beilstein J. Nanotechnol. 2017, 8, 2069–2082, doi:10.3762/bjnano.8.207

• ][36][37]. Only at low voltages, transport follows a linear, ohmic behavior [36]. From moderate to high voltages, non-linear behavior is expected and is controlled by distributed carrier traps within the organic layer. In order to use Ohm’s law to analyze the data, the measurements should be performed

Two-dimensional carbon-based nanocomposites for photocatalytic energy generation and environmental remediation applications

• Suneel Kumar,
• Ashish Kumar,
• Ashish Bahuguna,
• Vipul Sharma and
• Venkata Krishnan

Beilstein J. Nanotechnol. 2017, 8, 1571–1600, doi:10.3762/bjnano.8.159

• level, which traps holes and hence the photoinduced electrons were transferred from the CB of g-C3N4 to the CB of TiO2 as per their band potentials (Figure 10), which further leads to the photocatalytic reaction for fuel production. Hence the synergetic effect of boron doping and heterojunction

Parylene C as a versatile dielectric material for organic field-effect transistors

• Tomasz Marszalek,
• Maciej Gazicki-Lipman and
• Jacek Ulanski

Beilstein J. Nanotechnol. 2017, 8, 1532–1545, doi:10.3762/bjnano.8.155

• traps but they cannot entirely eliminate surface SiOH groups [39]. When polyethylene was used as a buffer dielectric, unhindered charge transport was observed [40], suggesting that thin polymer layers could play the same role as SAMs do. For this reason, polymers are often used as a part of twin

• demonstrate how important it is to select a compatible dielectric material with reduced number of charge traps [2]. The effect of the gate dielectric material on charge-carrier transport in single-crystal transistors was also discussed in the case of devices based on TTF derivatives, also characterized as a

• summarize, it can be concluded that by optimizing the process of Parylene C deposition no defects in the semiconductor layer and at semiconductor/encapsulation layer interface are formed and, therefore, no additional charge traps are created at that interface. It should be pointed out that the results

Spin-chemistry concepts for spintronics scientists

• Konstantin L. Ivanov,
• Alexander Wagenpfahl,
• Carsten Deibel and
• Jörg Matysik

Beilstein J. Nanotechnol. 2017, 8, 1427–1445, doi:10.3762/bjnano.8.143

• -called spin blocking can be cancelled by the magnetic field. The spin mixing seems to be most pronounced in the slow hopping regime [84], for instance, when deep traps reduce the charge carrier mobility [85]. Oppositely charged polaron pairs [16] (or correlated radical ion pairs) can show a bipolar OMAR

AgCl-doped CdSe quantum dots with near-IR photoluminescence

• Pavel A. Kotin,
• Sergey S. Bubenov,
• Natalia E. Mordvinova and
• Sergey G. Dorofeev

Beilstein J. Nanotechnol. 2017, 8, 1156–1166, doi:10.3762/bjnano.8.117

• . Halide ions have their own hole traps [26], which can reduce the energy of PL. They also play an important role in the surface passivation, which can lead to higher QYs and result in anisotropic growth of nanoparticles [27]. Herein, we explore the combined influence of both Ag and Cl ions in the modified

• obtained directly after the synthesis were lower than 10%. The possible explanation of poor exciton intensity could be the presence of a large number of volume Ag exciton traps. After a long time Ag leaves the NPs and the number of Ag exciton traps is greatly reduced. At the same time the intensity of the

Biological and biomimetic materials and surfaces

• Stanislav Gorb and
• Thomas Speck

Beilstein J. Nanotechnol. 2017, 8, 403–407, doi:10.3762/bjnano.8.42

• [12]. Plant systems Poppinga et al. conducted snap–trap closure experiments in air and under water and presented strong evidence that adult snaps of the Venus flytrap (Dionaea muscipula) are similarly fast in aerial and submersed states. The authors showed that minute seedling traps are much slower

Impact of contact resistance on the electrical properties of MoS₂ transistors at practical operating temperatures

• Filippo Giannazzo,
• Gabriele Fisichella,
• Aurora Piazza,
• Salvatore Di Franco,
• Giuseppe Greco,
• Simonpietro Agnello and
• Fabrizio Roccaforte

Beilstein J. Nanotechnol. 2017, 8, 254–263, doi:10.3762/bjnano.8.28

• ≈ 9.1 × 10−5 F/m2 (ε0 is the vacuum dielectric constant, εox = 3.9, tox = 380 nm, the permittivity and the thickness of the SiO2 film, respectively), on the capacitance of the MoS2 depletion region, Cs, as well as on the capacitance associated with MoS2/SiO2 interface traps, Cit [5]. In the depletion

• Vth with temperature, the role of interface states at SiO2/MoS2 interface must be considered. The difference between the experimental Vth−VFB and theoretical Vth,id−VFB,id can be described by a term ΔVit = qNit/Cox, where Nit is the density of trapped/detrapped electrons by SiO2 interface traps. These

• interface traps exhibit a donor like behavior, i.e., they are positively charged above the Fermi level (when they are empty) and neutral below the Fermi level (when they are filled by electrons) [13]. Hence, electron trapping results in a neutralization of the interface states, resulting in a positive shift

Tandem polymer solar cells: simulation and optimization through a multiscale scheme

• Fanan Wei,
• Ligang Yao,
• Fei Lan,
• Guangyong Li and
• Lianqing Liu

Beilstein J. Nanotechnol. 2017, 8, 123–133, doi:10.3762/bjnano.8.13

• recombination between one free carrier and one carrier stuck in traps or dead ends in the active layer, while other recombination events were classified as bimolecular. Then, we varied the D/A weight ratios in the P3HT/PCBM active layer and repeated the mesoscale simulations. For more details of the MC

• explanation is that many of the carriers can be captured in dead ends or traps because of the complex inner structures in the blend. In such a case, the high electric field will reduce the possibility for the trapped carriers to jump out from the traps, which leads to a lower effective carrier mobility