Core-level spectra and molecular deformation in adsorption: V-shaped pentacene on Al(001)

• Anu Baby,
• He Lin,
• Gian Paolo Brivio,
• Luca Floreano and
• Guido Fratesi

Beilstein J. Nanotechnol. 2015, 6, 2242–2251, doi:10.3762/bjnano.6.230

• potential candidate in the field of organic electronic devices [1][2][3][4][5]. It acts as a p-type organic semiconductor in its intrinsic state with high hole mobility and exhibits a very high melting point [6]. The pentacene–Al junction is known to exhibit a Schottky barrier and, hence, finds numerous

Possibilities and limitations of advanced transmission electron microscopy for carbon-based nanomaterials

• Xiaoxing Ke,
• Carla Bittencourt and
• Gustaaf Van Tendeloo

Beilstein J. Nanotechnol. 2015, 6, 1541–1557, doi:10.3762/bjnano.6.158

• at the contact is believed to contribute to the already present Schottky barrier in metal–CNT contacts, providing an alternative perspective in studying metal–CNTs contacts. Undoubtedly, advances in TEM have offered unrivaled opportunities in studying carbon nanostructures in both 2D and 3D in a

Palladium nanoparticles anchored to anatase TiO₂ for enhanced surface plasmon resonance-stimulated, visible-light-driven photocatalytic activity

• Kah Hon Leong,
• Hong Ye Chu,
• Shaliza Ibrahim and
• Pichiah Saravanan

Beilstein J. Nanotechnol. 2015, 6, 428–437, doi:10.3762/bjnano.6.43

• Schottky barrier at which an internal electric field close to the interface is generated. Hence, it will drive the electrons and holes to move in different directions and the photon energies of electrons excited upon LSPR excitation is able to cross the energy junction at interface. As a result electrons

• are transferred from Pd NPs to the CB of TiO2 [9][62]. Furthermore with the formation of the Schottky barrier, the lifetime of the charge carriers is increased [63]. This mechanism is illustrated in Figure 10. Meanwhile, the study of the influence of the palladium weight percentage (0.5 wt %, 1.0 wt

• anchoring of Pd NPs onto the surface of TiO2, and the large size of the Pd NPs contributed to the visible-light absorption. Localized surface plasmon resonance (LSPR) and the formation of a Schottky barrier at the TiO2 interface also occured. The prepared heterogeneous photocatalysts exhibited superior

Electrical contacts to individual SWCNTs: A review

• Wei Liu,
• Christofer Hierold and
• Miroslav Haluska

Beilstein J. Nanotechnol. 2014, 5, 2202–2215, doi:10.3762/bjnano.5.229

• connected to electrical circuitry, which is typically achieved by contacting the SWCNTs with metal. Due to possible low channel resistance (or even ballistic conduction), the metal–nanotube contact resistance can dominate the performance of these transistors. Devices with a low Schottky barrier height (SBH

• of the Schottky barrier should depend on the work function of the chosen metals. In fact this rule is commonly violated for bulk semiconductors due to the existence of metal induced gap states (MIGS) at the metal–semiconductor interface [11][12]. For bulk semiconductors, MIGS cause a dipole sheet at

• the metal–semiconductor interface and lead to the so-called Fermi level pinning effect, that is, when the Fermi level tends to be fixed at a constant position in the band gap of the semiconductor [13]. The net result is that the Schottky barrier height is less sensitive to the work function difference

Advances in NO₂ sensing with individual single-walled carbon nanotube transistors

• Kiran Chikkadi,
• Matthias Muoth,
• Cosmin Roman,
• Miroslav Haluska and
• Christofer Hierold

Beilstein J. Nanotechnol. 2014, 5, 2179–2191, doi:10.3762/bjnano.5.227

• work function difference between the metal and the nanotube, a Schottky barrier is commonly formed at both contacts. The channel conductivity is controlled by a gate electrode that is separated from the nanotube channel by a gate dielectric. In Schottky barrier field-effect transistors, the effect of

• the gate voltage is to change the width of the Schottky barrier, which controls the current through the device. Carbon nanotube transistors often operate as Schottky-barrier field-effect transistors because the back-gated architecture that is typically employed for CNFET gas sensors covers the entire

• ultraviolet photoelectron spectroscopy [32] (XPS and UPS) have been used to understand the mechanism of this work function change. For polar molecules such as NO2, a dipole layer is expected to be formed at the surface of the metal, thereby modifying the metal work function [33][34]. In Schottky barrier

Effect of channel length on the electrical response of carbon nanotube field-effect transistors to deoxyribonucleic acid hybridization

• Hari Krishna Salila Vijayalal Mohan,
• Jianing An,
• Yani Zhang,
• Chee How Wong and
• Lianxi Zheng

Beilstein J. Nanotechnol. 2014, 5, 2081–2091, doi:10.3762/bjnano.5.217

• induced surface charges, which in turn, modulates their electrical transport [16][17]. However, most of the previous FET-based investigations for DNA–DNA hybridization detection predominantly used short individual nanotubes or random networks, which revealed Schottky barrier modification as their dominant

• sensing mechanism in a dry back-gated configuration [18][19]. A major issue with the Schottky barrier dependent mechanism is distinguishing hybridization from other biological events in the presence of CNT–metal contact electrodes during detection. These events increase the risk of a false signal arising

• gate voltage), the influence of Schottky barrier reduces, which results in lower contact resistance [35], as compared to the near-threshold regime (lower gate bias). Therefore, the contribution from the contacts to the mobility change at higher gate voltage is greater compared to lower gate voltage

Kelvin probe force microscopy of nanocrystalline TiO₂ photoelectrodes

• Alex Henning,
• Gino Günzburger,
• Res Jöhr,
• Yossi Rosenwaks,
• Biljana Bozic-Weber,
• Catherine E. Housecroft,
• Edwin C. Constable,
• Ernst Meyer and
• Thilo Glatzel

Beilstein J. Nanotechnol. 2013, 4, 418–428, doi:10.3762/bjnano.4.49

• . The observed logarithmic dependence demonstrates a photodiode behavior according to Equation 5 and is an indication for a built-in (Schottky barrier) potential at the interface. It should be noted that the photocurrent, Jph, in Equation 5 is approximately proportional to the light intensity, I. When

A highly pH-sensitive nanowire field-effect transistor based on silicon on insulator

• Denis E. Presnov,
• Sergey V. Amitonov,
• Pavel A. Krutitskii,
• Valentina V. Kolybasova,
• Igor A. Devyatov,
• Vladimir A. Krupenin and
• Igor I. Soloviev

Beilstein J. Nanotechnol. 2013, 4, 330–335, doi:10.3762/bjnano.4.38

• asymmetric. The hole conductivity of the transistor was very low down to gate voltages of Vg = −10 V. For positive voltages at the gate (when an inverse electron channel formed), typical I–V-curves with ohmic and saturation regions were measured. Such characteristic asymmetry is induced by a Schottky barrier

• the distance between the NW and the Schottky barriers in our design is about several microns, which is far larger than the phase-breaking length [24], current fluctuations in the NW and in the Schottky barrier were uncorrelated. According to this, one can calculate the spectral density of the

• transport-current fluctuations SI by considering an equivalent scheme with a series connection of resistors modelling NW and Schottky barriers with uncorrelated fluctuation generators: Our four-probe measurements of the NW resistance R and Schottky barrier resistance RB at room temperature show that R >> RB

Photoresponse from single upright-standing ZnO nanorods explored by photoconductive AFM

• Igor Beinik,
• Markus Kratzer,
• Astrid Wachauer,
• Lin Wang,
• Yuri P. Piryatinski,
• Gerhard Brauer,
• Xin Yi Chen,
• Yuk Fan Hsu,
• Aleksandra B. Djurišić and
• Christian Teichert

Beilstein J. Nanotechnol. 2013, 4, 208–217, doi:10.3762/bjnano.4.21

• indicates an increase of the charge-carrier concentration. The rectifying I–V characteristics are associated with the Schottky contact between AFM tip and ZnO NR. The Schottky barrier heights (SBHs) were estimated, using the same method as applied in [31], to be 0.22 ± 0.06 eV for the dark and 0.18 ± 0.06

Synthesis and electrical characterization of intrinsic and in situ doped Si nanowires using a novel precursor

• Wolfgang Molnar,
• Alois Lugstein,
• Tomasz Wojcik,
• Peter Pongratz,
• Norbert Auner,
• Christian Bauch and
• Emmerich Bertagnolli

Beilstein J. Nanotechnol. 2012, 3, 564–569, doi:10.3762/bjnano.3.65

• performed with back-gated Schottky-barrier NW-FETs and four-point measurement modules. The results of the four-point measurements and the back-gated measurements are illustrated in Figure 3. The four-point measurements of nominally intrinsic NWs grown with pure OCTS revealed a resistivity of about 5.9 kΩ·cm

• with diffraction images in the inset. Semilogarithmic I/V plot of intrinsic, p- and n-type NWs. The calculated specific resistivity values are shown next to the respective curves. The transfer characteristic of the intrinsic NW integrated into a back-gated Schottky-barrier NW-FET and a SEM image of a

Highly efficient ZnO/Au Schottky barrier dye-sensitized solar cells: Role of gold nanoparticles on the charge-transfer process

• Tanujjal Bora,
• Htet H. Kyaw,
• Soumik Sarkar,
• Samir K. Pal and
• Joydeep Dutta

Beilstein J. Nanotechnol. 2011, 2, 681–690, doi:10.3762/bjnano.2.73

• -photon-count (TCSPC) spectroscopy technique was used to explore the charge-transfer mechanism in the ZnO/Au-nanocomposite DSSC. Due to the formation of the Schottky barrier at the ZnO/Au interface and the higher optical absorptions of the ZnO/Au photoelectrodes arising from the surface plasmon absorption

• both in the presence and absence of Au nanoparticles. A slower fluorescence decay associated with the electron recombination process, observed in the presence of Au nanoparticles, confirmed the blocking of the electron transfer from ZnO back to the dye or electrolyte by the Schottky barrier formed at

• the ZnO/Au interface. For large area DSSC (1 cm2), ~130% enhancement in PCE (from 0.50% to 1.16%) was achieved after incorporation of the Au nanoparticles into the ZnO nanorods. Keywords: dye-sensitized solar cell; gold nanoparticle; picosecond spectroscopy; Schottky barrier; zinc oxide nanorod

Schottky junction/ohmic contact behavior of a nanoporous TiO₂ thin film photoanode in contact with redox electrolyte solutions

• Masao Kaneko,
• Hirohito Ueno and
• Junichi Nemoto

Beilstein J. Nanotechnol. 2011, 2, 127–134, doi:10.3762/bjnano.2.15

• of a Schottky barrier is proved. From the intercept (= E − Efb – (kB T)/q) of the plots on the potential axis, the flat band potential is obtained, and from the slope (= 2/(ε·ε0·q·N)), the carrier density N can be estimated. The flat band potential Efb of a nanoporous TiO2 thin film photoanode soaked

• with MEA-attached Pt (1 cm × 1 cm) as the counter electrode and Ag/AgCl as the reference electrode. The light intensity was 3.5 mW·cm−2 (UV-A region). Scan rate: 100 mV·s−1. Formation of a Schottky barrier (junction) in an n-semiconductor photoanode at the interface with aqueous electron donor