Hexagonal boron nitride: a review of the emerging material platform for single-photon sources and the spin–photon interface

• Stefania Castelletto,
• Faraz A. Inam,
• Shin-ichiro Sato and
• Alberto Boretti

Beilstein J. Nanotechnol. 2020, 11, 740–769, doi:10.3762/bjnano.11.61

Comparison of fresh and aged lithium iron phosphate cathodes using a tailored electrochemical strain microscopy technique

• Matthias Simolka,
• Hanno Kaess and
• Kaspar Andreas Friedrich

Beilstein J. Nanotechnol. 2020, 11, 583–596, doi:10.3762/bjnano.11.46

• inactive material traps Li-ions, which reduces the remaining capacity of the cell. Therefore, the presented ESM measurements visualize the reduction of the electrochemical activity and the loss of lithium inventory of the sample due to ageing on the nanometer scale. With that, ESM offers a higher

Implementation of data-cube pump–probe KPFM on organic solar cells

• Benjamin Grévin,
• Olivier Bardagot and
• Renaud Demadrille

Beilstein J. Nanotechnol. 2020, 11, 323–337, doi:10.3762/bjnano.11.24

• exponents lower than 0.7 required for fitting of the spectroscopic curves (with the exception of the data in Figure 6f). These traps can be partially filled by applying a continuous white light background in addition to the pump pulse, which results in a significant reduction of the effective decay-time

• ) indicate that the effective carrier mobility strongly depends on the photocarrier concentration, which is inversely proportional to the optical power. Such a situation has been reported for different organic blends [33][34][35]. In some models, traps are the source of this concentration-dependent mobility

Recent progress in perovskite solar cells: the perovskite layer

• Xianfeng Dai,
• Ke Xu and
• Fanan Wei

Beilstein J. Nanotechnol. 2020, 11, 51–60, doi:10.3762/bjnano.11.5

• the bladed films and can even passivate charge traps to further improve the device performance. Finally, stabilized PCEs of 15.3% and 14.6% were reached for devices with active areas of 33.0 cm2 and 57.2 cm2 at a high coating speed of 180 m·h−1. More importantly, the surfactants could be a kind of

Nontoxic pyrite iron sulfide nanocrystals as second electron acceptor in PTB7:PC₇₁BM-based organic photovoltaic cells

• Olivia Amargós-Reyes,
• José-Luis Maldonado,
• Omar Martínez-Alvarez,
• María-Elena Nicho,
• José Santos-Cruz,
• Juan Nicasio-Collazo,
• Irving Caballero-Quintana and
• Concepción Arenas-Arrocena

Beilstein J. Nanotechnol. 2019, 10, 2238–2250, doi:10.3762/bjnano.10.216

• ) AFM images of the OPVs with different concentrations of FeS2 recorded in the noncontact mode. The roughness of the OPV surface is increased gradually as the FeS2 concentration increases (Table 1 and Figure 7), such that traps for the charge carriers could occur and the leakage current could increase

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

• interface traps (known as Pb-type defects). These interface traps produce scattering centers that can affect the mobility of charge carriers, thus altering the transport properties [11]. Moreover, sharp interfaces with an abrupt change in the dielectric constant or thermal expansion coefficients give rise

A highly efficient porous rod-like Ce-doped ZnO photocatalyst for the degradation of dye contaminants in water

• Binjing Hu,
• Qiang Sun,
• Chengyi Zuo,
• Yunxin Pei,
• Siwei Yang,
• Hui Zheng and
• Fangming Liu

Beilstein J. Nanotechnol. 2019, 10, 1157–1165, doi:10.3762/bjnano.10.115

• levels serve as electron traps for photogenerated electrons. In this way, the recombination of photoinduced holes and electrons is suppressed, which accelerates the transfer of electrons to dissolve oxygen molecules and to produce more superoxide radicals to degrade probe dyes [9][22]. As a result, CZO-4

Advanced scanning probe lithography using anatase-to-rutile transition to create localized TiO₂ nanorods

• Julian Kalb,
• Vanessa Knittel and
• Lukas Schmidt-Mende

Beilstein J. Nanotechnol. 2019, 10, 412–418, doi:10.3762/bjnano.10.40

• charging by trapping of electrons from the electron beam in neutral traps such as OH groups [43]. However, this effect becomes significantly stronger with increasing beam intensity and remains for many days in a humid environment. Hence, it results more likely from electron-beam-induced surface smoothing

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