Experimental determination of the light-trapping-induced absorption enhancement factor in DSSC photoanodes

• Serena Gagliardi and
• Mauro Falconieri

Beilstein J. Nanotechnol. 2015, 6, 886–892, doi:10.3762/bjnano.6.91

• produced by the concurrent phenomena of light absorption by dye molecules and light trapping in the mesoporous, titania photoanode structure. The decoupling of these two phenomena is important for device characterization and the design of novel photoelectrode geometries with increased optical performance

• . In this paper, this task is addressed by introducing a spectral absorption enhancement factor as a parameter to quantify the light trapping effect. The experimental value of this parameter was obtained by comparing the experimentally determined fraction of absorbed light by a dye-sensitized

• extreme cases of the absence of light trapping and maximum light trapping. Accordingly, the photocurrent was calculated under the assumption of solar irradiation, which defined two useful boundaries. Using the experimentally derived values of the spectral absorption enhancement factor in the photoanode

Applications of three-dimensional carbon nanotube networks

• Manuela Scarselli,
• Paola Castrucci,
• Francesco De Nicola,
• Ilaria Cacciotti,
• Francesca Nanni,
• Emanuela Gatto,
• Mariano Venanzi and
• Maurizio De Crescenzi

Beilstein J. Nanotechnol. 2015, 6, 792–798, doi:10.3762/bjnano.6.82

• wettability is well described by a Cassie–Baxter model [20] for which a quite rough surface allows air trapping and ensures the high contact angle measured. In particular, in such a system pores in the random network (i.e., void fraction) favor air trapping due to the strong capillary force that the surface

Statistics of work and orthogonality catastrophe in discrete level systems: an application to fullerene molecules and ultra-cold trapped Fermi gases

• Antonello Sindona,
• Michele Pisarra,
• Mario Gravina,
• Cristian Vacacela Gomez,
• Pierfrancesco Riccardi,
• Giovanni Falcone and
• Francesco Plastina

Beilstein J. Nanotechnol. 2015, 6, 755–766, doi:10.3762/bjnano.6.78

• value of 19.10%. 2.2 The harmonically trapped Fermi gas We now take a spin 1/2 gas of weakly interacting atoms in a parabolic potential of a typical length x0 and trapping frequency ω. Neglecting the inter-particle forces, the one-fermion Hamiltonian is that of a harmonic oscillator with eigenvalues

• efficiently describe an ultra-cold Fermi gas probed by a two-level impurity, with the parabolic potential mimicking the magneto-optical trapping potential, may be found for example in [25][28][31][32][48]. Let us further assume that the perturbation is spatially structure-less and localized at the center of

Simple approach for the fabrication of PEDOT-coated Si nanowires

• Mingxuan Zhu,
• Marielle Eyraud,
• Judikael Le Rouzo,
• Nadia Ait Ahmed,
• Florence Boulc’h,
• Claude Alfonso,
• Philippe Knauth and
• François Flory

Beilstein J. Nanotechnol. 2015, 6, 640–650, doi:10.3762/bjnano.6.65

• spectral range was obtained for these structures, evidencing their excellent antireflective properties. The etched SiNWs nanostructures can be further modified by using a tapering technique, which further preserves the strong light trapping effect. P-type PEDOT was grown on these SiNWs using

• concentration of the AgNO3 solution influences the morphology. However, for this study, only those SiNWs that exhibit good optical performance (low reflection at the surface, i.e., a light trapping effect) which were suitable for PEDOT deposition (using a KOH solution after the EMACE process) were addressed

• strong light trapping effect [1], the SiNWs produced without tapering exhibit a reflection of less than 2% over the entire visible range. The reflection of the tapered samples increases with the tapering duration. After 50 s of tapering, the SiNWs have a reflection greater than 10% due to the reduced

Novel ZnO:Ag nanocomposites induce significant oxidative stress in human fibroblast malignant melanoma (Ht144) cells

• Syeda Arooj,
• Samina Nazir,
• Akhtar Nadhman,
• Nafees Ahmad,
• Bakhtiar Muhammad,
• Ishaq Ahmad,
• Kehkashan Mazhar and
• Rashda Abbasi

Beilstein J. Nanotechnol. 2015, 6, 570–582, doi:10.3762/bjnano.6.59

• nanocomposites were studied regarding their ability to generate ROS and lipid peroxidation by chemical trapping method (DPBF; 1,3-diphenylisobenzofuran) and the thiobarbituric acid-reactive species (TBARs) assay, respectively. Generation of various ROS species was studied by using scavengers such as mannitol

• trapping (DPBF) The release of 1O2 into aqueous solution was estimated indirectly by using the DPBF assay. DPBF reacts irreversibly with 1O2 causing a decrease in its absorption intensity at 410 nm. The different NPs (100 µg/mL) were mixed in DPBF solution and upon irradiation absorption was measured over

• generated and their IC50 values were calculated. The IC50 value for the nanoparticles represents the concentration that inhibits 50% of cell growth. The experiments were performed twice with triplicates for each sample. Detection of singlet oxygen by chemical trapping 1,3-Diphenylisobenzofuran (DPBF) was

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

• indicates a lower recombination rate due to more electrons being transferred or trapped. The emission peak of Pd/TiO2 is obviously quenched as compared to that TiO2. This further revealed that the deposition of Pd NPs has enhanced the trapping or transfer of electrons thereby suppressing the recombination

Influence of size, shape and core–shell interface on surface plasmon resonance in Ag and Ag@MgO nanoparticle films deposited on Si/SiO_x

• Sergio D’Addato,
• Daniele Pinotti,
• Maria Chiara Spadaro,
• Guido Paolicelli,
• Vincenzo Grillo,
• Sergio Valeri,
• Luca Pasquali,
• Luca Bergamini and
• Stefano Corni

Beilstein J. Nanotechnol. 2015, 6, 404–413, doi:10.3762/bjnano.6.40

• , it was found that Au NPs [5] and Ag NPs [6] deposited on thin film- and wafer-based Si solar cells can enhance their photon absorption due to the occurrence of surface plasmon resonance (SPR), which serves to scatter the incident radiation in the UV–vis region and to increase the light trapping

Exploiting the hierarchical morphology of single-walled and multi-walled carbon nanotube films for highly hydrophobic coatings

• Francesco De Nicola,
• Paola Castrucci,
• Manuela Scarselli,
• Francesca Nanni,
• Ilaria Cacciotti and
• Maurizio De Crescenzi

Beilstein J. Nanotechnol. 2015, 6, 353–360, doi:10.3762/bjnano.6.34

• wettability. It is indeed well-established [12][13] that on composite rough surfaces a hierarchical morphology may induce a wetting transition from Wenzel [1] to Cassie–Baxter [9] state owing to air trapping. Moreover, this transition may occur by passing through thermodynamically metastable states [13][14

Synthesis, characterization, monolayer assembly and 2D lanthanide coordination of a linear terphenyl-di(propiolonitrile) linker on Ag(111)

• Zhi Chen,
• Svetlana Klyatskaya,
• José I. Urgel,
• David Écija,
• Olaf Fuhr,
• Willi Auwärter,
• Johannes V. Barth and
• Mario Ruben

Beilstein J. Nanotechnol. 2015, 6, 327–335, doi:10.3762/bjnano.6.31

• diiodoterphenyl 4 was subjected to a cross-coupling reaction with propargyl alcohol in the presence of catalytic amounts of Pd(II) salts, leading to the formation of the intermediary compound 5. This compound was subsequently reacted by a tandem manganese dioxide-mediated alcohol oxidation with in situ trapping

Synthesis of boron nitride nanotubes and their applications

• Saban Kalay,
• Zehra Yilmaz,
• Ozlem Sen,
• Melis Emanet,
• Emine Kazanc and
• Mustafa Çulha

Beilstein J. Nanotechnol. 2015, 6, 84–102, doi:10.3762/bjnano.6.9

• placed into a quartz tube with one end closed. The quartz tube was placed in a tube furnace for the growth of high yield BNNTs at 1100–1200 °C based on the growth vapor trapping (GVT) mechanism as seen in the SEM image in Figure 1. The latest BOCVD method was studied by Nithya et al. [57]. They claim

Low-cost plasmonic solar cells prepared by chemical spray pyrolysis

• Erki Kärber,
• Atanas Katerski,
• Ilona Oja Acik,
• Valdek Mikli,
• Arvo Mere,
• Ilmo Sildos and
• Malle Krunks

Beilstein J. Nanotechnol. 2014, 5, 2398–2402, doi:10.3762/bjnano.5.249

• of solar cells scales with the complexity of the technology involved as well as the price and volume of the semiconductors used (but in particular, the absorber material). The use of very thin absorber layers in solar cells requires adoption of various light trapping techniques to take advantage of

Liquid-phase exfoliated graphene: functionalization, characterization, and applications

• Mildred Quintana,
• Jesús Iván Tapia and
• Maurizio Prato

Beilstein J. Nanotechnol. 2014, 5, 2328–2338, doi:10.3762/bjnano.5.242

• and damage of graphene layers, (3) the Fc–CHO adsorption at the edges of graphene layers inducing the rolling up of a sheet to form a nanoscroll (schematically indicated in Figure 4), (4) the trapping of Fc–CHO into the scroll, and (5) finally, Fc–CHO accepts and donates unpaired electrons to the

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

• trapping in the oxide and the dielectrics surrounding the nanotube. Robert-Peillard et al. [61] developed a model to qualitatively describe this phenomenon by using Fowler–Nordheim-type behavior for charge trapping by tunneling through the oxide layer. Although this model qualitatively describes the

• the gate voltage, the duration in which trapping can occur is reduced, and the charges have time to de-trap in the time between gate pulses, thereby reducing the induced screening. Building on this idea, Mattmann et al. [64][65] showed that by applying alternating gate pulses, i.e, every positive gate

• readout electronics. If charge trapping in the nanotube surroundings is the primary cause of hysteresis, eliminating these sources, for example by using a protective layer to avoid resist contamination on the SWNT, could be effective in reducing hysteresis [17][66]. By using a protective layer that can

Sequence-dependent electrical response of ssDNA-decorated carbon nanotube, field-effect transistors to dopamine

• Hari Krishna Salila Vijayalal Mohan,
• Jianing An and
• Lianxi Zheng

Beilstein J. Nanotechnol. 2014, 5, 2113–2121, doi:10.3762/bjnano.5.220

• increase in H indicates the contribution of carrier scattering, charge transfer and charge trapping mechanisms, respectively [17]. From the above results, three important points are noteworthy. First, the absence of the response to UA in the ssDNA-decorated device suggests the lack of interaction between

• voltage (−∆Vth) [25]. The electron donation to the SWCNT reduces the charge carrier concentration inside the nanotubes resulting in the formation of static charges, which reduces the slope of the transfer curve by generation of carrier scattering (−∆gmp/gmp) [17]. Furthermore, the charge trapping ability

• gap, which indicates the combination of carrier scattering, charge transfer and charge trapping mechanisms. In addition, ssDNA decoration of the SWCNT improved DA recognition even in the presence of the interferent, UA, which highlights the enhancement in molecular selectivity. The devices exhibited a

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

• contribution of charge-trapping mechanism to the observed behavior [27][28]. Similar DNA detection studies using CNTs based on the principle of impedance exhibited detection limits as low as 100 aM [29]. To verify whether the source of the signal is from the CNT channel, ID–VG curves of FETs with only the

• threshold voltage shift for forward (ΔVfth) and reverse (ΔVrth) gate voltage sweeps, and the change in hysteresis gap (ΔH) with L increased from about −0.5 to −2.5 V, 1 to 3 V and 1.5 to 5 V, respectively. The shift in Vth to more negative values for the forward sweep indicates electron trapping by the

• guanine and adenine bases [28][31]. Similarly, the shift in Vth to more positive values for the reverse sweep is an indicator of hole trapping by the cytosine and thymine bases [28][31]. Thus, the increase in charge traps in the channel region leads to an overall shift in Vth for forward and reverse

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

• enhancement. This is only valid for small NCs, while the enhancement diminishes as the density of larger NCs increases. As already mentioned, one of the main applications of the embedded NCs is in memory devices. To check the charge trapping properties of the embedded NCs, different electrical

• characterization techniques could be applied. The most common is the capacitance-voltage (C–V) technique that gives information about the memory window. Moreover, C–V gives valuable information as far as interface-defects and oxide defects are concerned. There are numerous studies on the charge-trapping properties

• of embedded NCs. However, it should be noted that in a significant number of those, the effects of defects (either interface-related or in the oxide) have been completely neglected, and the observed memory window (the flat band voltage shift ΔVFB) has been unconditionally ascribed to the NCs trapping

Magnesium batteries: Current state of the art, issues and future perspectives

• Rana Mohtadi and
• Fuminori Mizuno

Beilstein J. Nanotechnol. 2014, 5, 1291–1311, doi:10.3762/bjnano.5.143

• deposition/stripping are volatile as they are ether-based. To overcome this challenge, one strategy would be trapping the solvent, used to solvate the magnesium ions, within a polymeric matrix. The electrolyte formed in this case is referred to as a gel electrolyte. This concept was previously applied to Li

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

• -temperature wet-chemical process. Photoluminescence (PL) measurements at room temperature are then carried out in order to determine the role of vacancies, trapping levels, and the transition shift of the PL emission maximum in these samples. In order to study and optimize the four main factors affecting the

Organic and inorganic–organic thin film structures by molecular layer deposition: A review

• Pia Sundberg and
• Maarit Karppinen

Beilstein J. Nanotechnol. 2014, 5, 1104–1136, doi:10.3762/bjnano.5.123

Dry friction of microstructured polymer surfaces inspired by snake skin

• Martina J. Baum,
• Lars Heepe,
• Elena Fadeeva and
• Stanislav N. Gorb

Beilstein J. Nanotechnol. 2014, 5, 1091–1103, doi:10.3762/bjnano.5.122

• that a decrease in frictional coefficient is due to the reduction of adhesive components of the frictional mechanisms [51][52]. Another approach to explain the reduction in frictional coefficient on many microstructured surfaces could be the possibility of trapping of loose wear particles within the

Functionalized nanostructures for enhanced photocatalytic performance under solar light

• Liejin Guo,
• Dengwei Jing,
• Maochang Liu,
• Yubin Chen,
• Shaohua Shen,
• Jinwen Shi and
• Kai Zhang

Beilstein J. Nanotechnol. 2014, 5, 994–1004, doi:10.3762/bjnano.5.113

• found to have a close relationship with the doping amount of Ni ions and the highest activity was obtained when the amount of Ni doping was 1%. Here, the enhanced photocatalytic activity was attributed to doped Ni2+ ions which served as shallow trapping sites, preferentially trapping photoexcited holes

• . The assumption of the role of Ni2+ as shallow trapping sites could be rationalized by considering that the energy level of Ni2+ is located very close to the valence band edge of TiO2 [16]. After trapping a hole, Ni2+ will be oxidized to Ni3+. However, due to the instability of Ni3+, it will quickly

• return to Ni2+ again. The shallow trapping can therefore separate the arrival of photogenerated charges at the surface, so the recombination at the channel surface of mesopores could be greatly reduced. However, when the doping concentration is higher than the optimal level, or for too large particles

Optimizing the synthesis of CdS/ZnS core/shell semiconductor nanocrystals for bioimaging applications

• Li-wei Liu,
• Si-yi Hu,
• Ying Pan,
• Jia-qi Zhang,
• Yue-shu Feng and
• Xi-he Zhang

Beilstein J. Nanotechnol. 2014, 5, 919–926, doi:10.3762/bjnano.5.105

• QDs, and 38 ns for CdS QDs. ZnS has a major influence on the lifetime decay profile of CdS/ZnS QDs. Trapping states are caused by surface defects located within the bandgap, which lead to the rise of nonradiative recombination. Emission spectra The emission spectra were collected by using a Fluorolog

Optical modeling-assisted characterization of dye-sensitized solar cells using TiO₂ nanotube arrays as photoanodes

• Jung-Ho Yun,
• Il Ku Kim,
• Yun Hau Ng,
• Lianzhou Wang and
• Rose Amal

Beilstein J. Nanotechnol. 2014, 5, 895–902, doi:10.3762/bjnano.5.102

• TiO2 nanoparticles, vertically well-ordered TNT-based DSSCs presented an enhanced electron transport by efficiently reducing the recombination possibility of photogenerated charge carriers through minimizing the trapping sites that normally exist in the grain boundaries of randomly oriented TiO2

Fibrillar adhesion with no clusterisation: Functional significance of material gradient along adhesive setae of insects

• Stanislav N. Gorb and
• Alexander E. Filippov

Beilstein J. Nanotechnol. 2014, 5, 837–845, doi:10.3762/bjnano.5.95

• contact may be increased due to the presence of specific micro- and nanostructures [1][2][3][4][5]. Crack trapping mechanisms in adhesive systems with multiple contacts provide advantages in attachment on rough substrates [6]. Also hierarchical organization of insect pad structures enables formation of

Measuring air layer volumes retained by submerged floating-ferns Salvinia and biomimetic superhydrophobic surfaces

• Matthias J. Mayser,
• Holger F. Bohn,
• Meike Reker and
• Wilhelm Barthlott

Beilstein J. Nanotechnol. 2014, 5, 812–821, doi:10.3762/bjnano.5.93

• the Cassie wetting state the solid–water interface is strongly reduced while the majority of the interface is between water and air, thereby trapping an air layer between water and surface. As a result the adhesion of the water to the surface is minimised and individual droplets often roll off at very