Unveiling the nature of atomic defects in graphene on a metal surface

• Karl Rothe,
• Nicolas Néel and
• Jörg Kröger

Beilstein J. Nanotechnol. 2024, 15, 416–425, doi:10.3762/bjnano.15.37

• ; scanning tunneling microscopy and spectroscopy; Introduction Defects in lattices of two-dimensional (2D) materials are considered as promising building blocks for tailoring electronic and phononic band structures, magnetic texture, photon emission, and charge carrier concentration [1]. In addition

SERS performance of GaN/Ag substrates fabricated by Ag coating of GaN platforms

• Magdalena A. Zając,
• Bogusław Budner,
• Malwina Liszewska,
• Bartosz Bartosewicz,
• Łukasz Gutowski,
• Jan L. Weyher and
• Bartłomiej J. Jankiewicz

Beilstein J. Nanotechnol. 2023, 14, 552–564, doi:10.3762/bjnano.14.46

• , nanostructured GaN platforms were prepared from commercial MOCVD-grown GaN on sapphire wafers by photoetching [45]. The 5 μm thick GaN layers were n-type with a carrier concentration n = 1 × 1018 cm−3 and a dislocation density of about 8 × 108 cm−2. The 5 × 5 mm samples were cut from 3″ MOCVD-grown GaN on

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

• lack of the required free carrier concentration. Similar to how the free carrier density of metals can be tuned by size, morphology, and refractive index of the nanomaterial, the free carrier density of semiconductors can be easily tuned by doping, temperature variations, or by phase transitions. LSPR

Photoelectrochemical water oxidation over TiO₂ nanotubes modified with MoS₂ and g-C₃N₄

• Phuong Hoang Nguyen,
• Thi Minh Cao,
• Tho Truong Nguyen,
• Hien Duy Tong and
• Viet Van Pham

Beilstein J. Nanotechnol. 2022, 13, 1541–1550, doi:10.3762/bjnano.13.127

• carrier concentration in MoS2/TNAs sample such in Figure 4. The mechanism for the enhanced activity of the heterojunctions can be explained by the Mott–Schottky results in Figure 5b,c. Generally, all samples show positive slopes, which proves that they are n-type semiconductors [53]. Equation 2 shows the

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

• sp2 carbon atoms [23], and its position displays a blueshift as the charge carrier concentration rises. That is, the frequency shift of the G band is proportional to |EF|, which sets the carrier concentration. Due to the method and materials employed for the graphene transfer being the same except for

• Figure 3b, respectively. The comparison of Figure 3c and Figure 3d shows that the G peak position is blueshifted in C4 samples compared to B2 samples (from an average of 1587 to 1593 cm−1), indicating that the charge carrier concentration did not rise as much when using B2 PMMA. This shows that B2 leaves

Assessment of the optical and electrical properties of light-emitting diodes containing carbon-based nanostructures and plasmonic nanoparticles: a review

• Keshav Nagpal,
• Erwan Rauwel,
• Frédérique Ducroquet and
• Protima Rauwel

Beilstein J. Nanotechnol. 2021, 12, 1078–1092, doi:10.3762/bjnano.12.80

• balances out the charge carrier concentration in the EML. InGaN-based LED have also benefited from the incorporation of AgNP in the EML. Consequently, a 14-fold PL enhancement and a seven-fold internal quantum efficiency have been reported [101]. A similar work reported an increase in the optical output

9.1% efficient zinc oxide/silicon solar cells on a 50 μm thick Si absorber

• Rafal Pietruszka,
• Bartlomiej S. Witkowski,
• Monika Ozga,
• Katarzyna Gwozdz,
• Ewa Placzek-Popko and
• Marek Godlewski

Beilstein J. Nanotechnol. 2021, 12, 766–774, doi:10.3762/bjnano.12.60

• was used as absorber of the solar spectrum. Carrier concentration, mobility, and resistivity were 4.3 × 1015 cm−3, 270 cm2·V−1·s−1, and 5.3 Ω·cm, respectively. The silicon wafer was cut into small square pieces, ca. 1.5 × 1.5 cm2 in size. Samples were cleaned in acetone, iso-propanol, and twice in

High-yield synthesis of silver nanowires for transparent conducting PET films

• Gul Naz,
• Hafsa Asghar,
• Muhammad Ramzan,
• Muhammad Arshad,
• Rashid Ahmed,
• Muhammad Bilal Tahir,
• Bakhtiar Ul Haq,
• Nadeem Baig and
• Junaid Jalil

Beilstein J. Nanotechnol. 2021, 12, 624–632, doi:10.3762/bjnano.12.51

• to their greater tube–tube resistance and lower inherent carrier concentration [10]. Today, noble metal nanomaterials are extensively employed owing to their superior conduction properties [11]. Among them only silver nanowires (AgNWs) films outperform ITO films in term of transmittance and

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

• nanowires impact graphene properties such as roughness, strain, and carrier concentration as well as density and type of induced defects. Tracing the manifestation of those interactions is important for the application of novel heterostructures. A detailed analysis of Raman spectra of graphene deposited on

• different nanowire substrates shows that bigger differences in nanowires height increase graphene strain, while a higher number of nanowires in contact with graphene locally reduces the strain. Moreover, the value of graphene carrier concentration is found to be correlated with the density of nanowires in

• graphene on rarely distributed nanowires. Our results also show modification of graphene carrier concentration and strain by different types of defects present in graphene. Therefore, the nanowire substrate is promising not only for strain and carrier concentration engineering but also for defect

Interface interaction of transition metal phthalocyanines with strontium titanate (100)

• Reimer Karstens,
• Thomas Chassé and
• Heiko Peisert

Beilstein J. Nanotechnol. 2021, 12, 485–496, doi:10.3762/bjnano.12.39

• semiconducting substrates, such a charge transfer would result in an interface doping of the substrate. Depending on the charge carrier concentration, the doping is accompanied by a shift of the Fermi level, visible as rigid energy shifts of all substrate-related core level spectra in photoemission. As an

Mapping of integrated PIN diodes with a 3D architecture by scanning microwave impedance microscopy and dynamic spectroscopy

• Rosine Coq Germanicus,
• Peter De Wolf,
• Florent Lallemand,
• Catherine Bunel,
• Serge Bardy,
• Hugues Murray and
• Ulrike Lüders

Beilstein J. Nanotechnol. 2020, 11, 1764–1775, doi:10.3762/bjnano.11.159

• majority carrier concentration and carrier types in semiconductors. In SCM, an electrically conductive tip scans in contact with the analysed sample surface. The tip and the probed sample volume, during contact, represent a metal–insulator–semiconductor (MIS) structure at the nanoscale [4][16][17]. A low

• detected phase sign indicates the majority carrier type and, hereby, enables the distinction between n-type and p-type semiconductor regions. In this way, SCM is applied to map the local carrier concentration and carrier type in semiconductor materials with a sensitivity between 1015 and 1020 atoms·cm−3

• and with the spatial resolution of AFM [17][19]. However, there are limits to the SCM and SSRM techniques. For example, for SCM, when the local carrier concentration is extremely low, the SCM signal may be undetectable and close to zero. For SSRM, a very good control of the applied force is necessary

Seebeck coefficient of silicon nanowire forests doped by thermal diffusion

• Shaimaa Elyamny,
• Elisabetta Dimaggio and
• Giovanni Pennelli

Beilstein J. Nanotechnol. 2020, 11, 1707–1713, doi:10.3762/bjnano.11.153

• 800 °C for 10 min. In the case of undoped samples, it is very difficult to establish the final charge carrier concentration, because it is strongly affected by the surface states of the nanostructures. In the case of doped samples, it is presumable that the doping concentration inside the nanowires is

Structural and electronic properties of SnO₂ doped with non-metal elements

• Jianyuan Yu,
• Yingeng Wang,
• Yan Huang,
• Xiuwen Wang,
• Jing Guo,
• Jingkai Yang and
• Hongli Zhao

Beilstein J. Nanotechnol. 2020, 11, 1321–1328, doi:10.3762/bjnano.11.116

• (substituting O) can effectively increase the carrier concentration and improve the conductivity. Majumder successfully prepared SnO2:F thin films using spray pyrolysis with SnF2 as the precursor. By adjusting the concentration of the precursor solution, doped SnO2 films with different properties were obtained

Electrochemical nanostructuring of (111) oriented GaAs crystals: from porous structures to nanowires

• Elena I. Monaico,
• Eduard V. Monaico,
• Veaceslav V. Ursaki,
• Shashank Honnali,
• Vitalie Postolache,
• Karin Leistner,
• Kornelius Nielsch and
• Ion M. Tiginyanu

Beilstein J. Nanotechnol. 2020, 11, 966–975, doi:10.3762/bjnano.11.81

• produced by GaAs anodization in NaCl electrolyte are similar to those previously observed in GaAs samples with the same carrier concentration anodized in HCl electrolyte [1]. This observation corroborates the results obtained from other III–V semiconductors, which state that the etching behavior depends

• ). According to Li and co-workers [17], the anodization of GaAs with a carrier concentration of about 1018 cm−3 in a KOH electrolyte can be categorized into three etching modes, deduced from the analysis of the current–voltage plot at a scan rate of 5 mV·s−1. Practically no etching occurs when the applied

• 400 nm can be produced by electrochemical etching of GaAs(100) wafers with a carrier concentration of the order of 1018 cm−3 in KOH electrolyte, or by etching of GaAs(111)B substrates in HNO3 electrolyte. However, the bundles of GaAs nanowires are formed only in some regions of the surface anodized in

Band tail state related photoluminescence and photoresponse of ZnMgO solid solution nanostructured films

• Vadim Morari,
• Aida Pantazi,
• Nicolai Curmei,
• Vitalie Postolache,
• Emil V. Rusu,
• Marius Enachescu,
• Ion M. Tiginyanu and
• Veaceslav V. Ursaki

Beilstein J. Nanotechnol. 2020, 11, 899–910, doi:10.3762/bjnano.11.75

• the PL band in ZnO with carrier concentration in the range of 1018 cm−3 to 1019 cm−3 is less than 50 meV. The concentration should be in the range of 1020 cm−3 to 1021 cm−3 to reach a FWHM value of 200 meV, i.e., the material should be highly conductive. On the other hand, the FWHM of PL bands in

Effect of Ag loading position on the photocatalytic performance of TiO₂ nanocolumn arrays

• Jinghan Xu,
• Yanqi Liu and
• Yan Zhao

Beilstein J. Nanotechnol. 2020, 11, 717–728, doi:10.3762/bjnano.11.59

• of photo-generated carriers, reducing the recombination of carriers [41]. The carriers can oxidize dissolved oxygen, H+ and H2O to active free radicals, and active free radicals can mineralize pollutants [42], where the chemical reaction is described as follows. Therefore, the increase of carrier

• concentration promotes the generation of active radicals, which increases the catalytic reaction rate and the catalytic efficiency [41][43]. In Figure 9b and 9d, a schematic diagram of the energy conversion of the two different nanocolumn structures is shown. In the AFT structure, the good transmittance of TiO2

Structural optical and electrical properties of a transparent conductive ITO/Al–Ag/ITO multilayer contact

• Aliyu Kabiru Isiyaku,
• Ahmad Hadi Ali and
• Nafarizal Nayan

Beilstein J. Nanotechnol. 2020, 11, 695–702, doi:10.3762/bjnano.11.57

• transmittance (86.1%) with a very low sheet resistance of 2.93 Ω/sq. The carrier concentration increased more than twice when the Al–Ag layer was inserted between the ITO layers. The figure of merit of the IAAI multilayer contact has been found to be high at 76.4 × 10−3 Ω−1 compared to a pure ITO contact (69.4

• carrier concentration in the ITO film is responsible for the blue shift and this can be clearly explained by the Burstein–Moss shift model [9][38]. Electrical properties of IAAI and ITO films obtained from four-point probe and Hall effect measurements are given in Table 2. Sheet resistance and resistivity

• works of Roh et al. [30] and Ding et al. [39] who used aluminum/palladium and copper interlayers, respectively. Carrier concentration and mobility of the IAAI films are higher than those of the ITO films. The IAAI carrier concentration increased from 6.2 × 10−21 to 8.9 × 10−21 cm−3 after annealing

Mobility of charge carriers in self-assembled monolayers

• Zhihua Fu,
• Tatjana Ladnorg,
• Hartmut Gliemann,
• Alexander Welle,
• Asif Bashir,
• Michael Rohwerder,
• Qiang Zhang,
• Björn Schüpbach,
• Andreas Terfort and
• Christof Wöll

Beilstein J. Nanotechnol. 2019, 10, 2449–2458, doi:10.3762/bjnano.10.235

• yield a charge carrier concentration of ≈1 × 1019 cm−3. Using a molecular volume of about 1 nm3, this value corresponds to about 0.01 electrons per molecule. This rather low value is fully consistent with the fact that the I–V curves (see Supporting Information File 1, Figure S5) reveal that we are

• mobility of anthracene and a charge carrier concentration of 1 × 1019 cm−3. Conclusion In conclusion, we demonstrate a novel approach for measuring charge transport in well-defined self-assembled monolayers, SAMs, containing aromatic cores. Using AFM-based lithography, islands of regular shape are carved

Improved adsorption and degradation performance by S-doping of (001)-TiO₂

• Xiao-Yu Sun,
• Xian Zhang,
• Xiao Sun,
• Ni-Xian Qian,
• Min Wang and
• Yong-Qing Ma

Beilstein J. Nanotechnol. 2019, 10, 2116–2127, doi:10.3762/bjnano.10.206

• −, it is neither a donor nor an acceptor and has no influence on the carrier concentration in TiO2. This is because S and O have the same number of outmost electrons. When RS/Ti is 2, S6+ begins to replace Ti4+ in the 2-S2 sample, whereupon the electron concentration becomes higher than the hole

Improvement of the thermoelectric properties of a MoO₃ monolayer through oxygen vacancies

• Wenwen Zheng,
• Wei Cao,
• Ziyu Wang,
• Huixiong Deng,
• Jing Shi and
• Rui Xiong

Beilstein J. Nanotechnol. 2019, 10, 2031–2038, doi:10.3762/bjnano.10.199

• to obtain converged results. Based on the framework of Boltzmann transport theory, the electrical conductivity, σ, and the Seebeck coefficient, S, can be expressed as: where the u is the chemical potential (corresponding to the carrier concentration), kB is the Boltzmann constant, e is the electron

• carrier concentration at three typical temperatures (T = 300, 500 and 700 K). Note that the n-type and p-type transport properties of MoO3 monolayer are uniform. Therefore, only p-type cases are shown here. As shown in Figure 2a, the Seebeck coefficient S of the MoO3 monolayer has the same value along the

• of the carrier concentration, as presented in Figure 2d. It is found that the ZT value is much higher along the x-axis than along the y-axis. The maximum ZT value along the x-axis reaches 0.84 at 700 K which is nearly four times larger than the corresponding value along the y-axis. The carrier

Prestress-loading effect on the current–voltage characteristics of a piezoelectric p–n junction together with the corresponding mechanical tuning laws

• Wanli Yang,
• Shuaiqi Fan,
• Yuxing Liang and
• Yuantai Hu

Beilstein J. Nanotechnol. 2019, 10, 1833–1843, doi:10.3762/bjnano.10.178

• -electrostatic solutions [32]. Distributions of electric potential, electric field and carrier concentration are quasi-electrostatically solved in section “Quasi-electrostatic analysis of a mechanically loaded piezoelectric p–n junction under a bias voltage” for a piezoelectric p–n junction exposed to mechanical

• concentrations in the p-zone and n-zone, respectively. ni stands for the intrinsic carrier concentration in the thermal equilibrium state. Based on the depletion layer hypothesis, we obtain the charge balance condition In addition, the contact potential difference of SCZ under nonzero σ can be solved as It

A carrier velocity model for electrical detection of gas molecules

• Ali Hosseingholi Pourasl,
• Sharifah Hafizah Syed Ariffin,
• Mohammad Taghi Ahmadi,
• Razali Ismail and
• Niayesh Gharaei

Beilstein J. Nanotechnol. 2019, 10, 644–653, doi:10.3762/bjnano.10.64

• . Thus, the energy dispersion relation of AGNR is developed considering the molecular adsorption effect using a tight binding (TB) method. The carrier velocity is calculated based on the density of states (DOS) and carrier concentration (n) to obtain I–V characteristics and to monitor its variation in

• path forward to overcome the constraints of experimental approaches. The adsorption of gas molecules can modulate different electrical and physical properties of the GNRs, such as density of states (DOS), carrier concentration, carrier velocity, I–V characteristics, and energy band structure. On the

• theoretical studies have confirmed that the velocity of the electrons is a function of carrier concentration (n) and density of states (DOS). The electron’s velocity is directly proportional to the DOS at any instance. The carrier velocity in the AGNR can be obtained by the accumulative velocity of all the

Enhancement in thermoelectric properties due to Ag nanoparticles incorporated in Bi₂Te₃ matrix

• Srashti Gupta,
• Dinesh Chandra Agarwal,
• Bathula Sivaiah,
• Sankarakumar Amrithpandian,
• Kandasami Asokan,
• Ajay Dhar,
• Binaya Kumar Panigrahi,
• Devesh Kumar Avasthi and
• Vinay Gupta

Beilstein J. Nanotechnol. 2019, 10, 634–643, doi:10.3762/bjnano.10.63

• enhancement of the Seebeck coefficient for a given carrier concentration. Several groups have used this approach using different metal–semiconductor combinations to improve thermoelectric properties [13][14]. One group has reported the synthesis of bismuth metal nanoparticles (NPs) were through a solvothermal

Geometrical optimisation of core–shell nanowire arrays for enhanced absorption in thin crystalline silicon heterojunction solar cells

• Robin Vismara,
• Olindo Isabella,
• Andrea Ingenito,
• Fai Tong Si and
• Miro Zeman

Beilstein J. Nanotechnol. 2019, 10, 322–331, doi:10.3762/bjnano.10.31

• taking place in less material. The higher carrier concentration results in a performance closer to the radiative limit, which is evidenced by the higher IQE observed at both short and long wavelengths. On the other hand, the lower EQE in the spectral region of 450–950 nm can be ascribed to a higher

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

• change in graphene resistance via altering the local carrier concentration. After that, a wave of research regarding graphene has been set off. The mass production of single-layered graphene is difficult. Another problem is that pristine graphene does not have a bandgap, which means it is not suitable