Hydrothermal synthesis of ZnO quantum dot/KNb₃O₈ nanosheet photocatalysts for reducing carbon dioxide to methanol

• Xiao Shao,
• Weiyue Xin and
• Xiaohong Yin

Beilstein J. Nanotechnol. 2017, 8, 2264–2270, doi:10.3762/bjnano.8.226

• m2/g ) of the nanosheets. Compared with pure KNb3O8 nanosheets, the yield of methanol was improved until a ZnO concentration of 2 wt % was reached. The highest yield of methanol was 1539.77 μmol/g/h for the 2 wt % ZnO quantum dots. This high yield can be ascribed to the heterojunction between the

• quantum dots form a heterojunction with KNb3O8 nanosheets to efficiently separate the photogenerated electron–hole pairs and inhibit their recombination while prolonging the lifetime of free carriers. The 2 wt % ZnO quantum dots loaded onto KNb3O8 nanosheets showed superior photocatalytic activity with

Growth and characterization of textured well-faceted ZnO on planar Si(100), planar Si(111), and textured Si(100) substrates for solar cell applications

• Chin-Yi Tsai,
• Jyong-Di Lai,
• Shih-Wei Feng,
• Chien-Jung Huang,
• Chien-Hsun Chen,
• Fann-Wei Yang,
• Hsiang-Chen Wang and
• Li-Wei Tu

Beilstein J. Nanotechnol. 2017, 8, 1939–1945, doi:10.3762/bjnano.8.194

• work provide important information for optimized growth of textured and well-faceted ZnO grown on wafer-based silicon solar cells and can be utilized for efficiency enhancement and optimization of device materials and structures, such as heterojunction with intrinsic thin layer (HIT) solar cells

• presented in this work have the potential to be a cost-effective alternative material for the substitution of the indium tin oxide (ITO) thin layer in heterojunction with intrinsic thin layer (HIT) solar cells [18]. Nevertheless, the optimization of the LPCVD growth conditions and parameters to increase the

Charge transfer from and to manganese phthalocyanine: bulk materials and interfaces

• Florian Rückerl,
• Daniel Waas,
• Bernd Büchner,
• Martin Knupfer,
• Dietrich R. T. Zahn,
• Francisc Haidu,
• Torsten Hahn and
• Jens Kortus

Beilstein J. Nanotechnol. 2017, 8, 1601–1615, doi:10.3762/bjnano.8.160

• our results in terms of MnPc salts and the related electronic properties. MnPc/F6TCNNQ: charge transfer at an interface The organic heterojunction MnPc/F6TCNNQ represents an example, where MnPc is involved in a charge transfer across an interface. In consideration of the results of the previous

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

• metals, metal oxide semiconductors and other nanomaterials, which can form efficient heterojunction with intimate contact between them, such as, point-to-face contact (0D-2D), line-to-face contact (1D-2D) and face-to-face contact (2D-2D) as presented in Figure 1. This is more beneficial for the rapid

• improve the light absorption of g-C3N4 and retard the recombination of photogenerated charge carriers to improve the photocatalytic efficiency. These strategies involve doping with metal atoms [70], non-metal doping [71], coupling with other carbon-based materials [72], and heterojunction formation by

• coupling with semiconductor materials such as TiO2 [73], ZnO [74], CdS [75], SnO2 [76], CeO2 [77], WO3 [78], Fe2O3 [79], Ag3PO4 [80], Ag3VO4 [81], ZnWO4 [82], SrTiO3 [83], BiVO4 [84], Bi2WO6 [85], BiOX [86][87], etc. These heterojunction formations have proved to be an effective method to improve the

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

• (electron) acceptor, as the photoactive layer. These two materials are combined either as a blend (the resulting architecture is called bulk heterojunction solar cell) or as two adjacent layers, yielding a planar heterojunction solar cell. The key processes for photovoltaic energy conversion in these types

• heterojunction, where an ultrafast electron transfer (et) to the acceptor occurs on the femtosecond time scale with almost unity yield. One reason is that this process is much faster than the intersystem crossing within, for example, the donor from S1 to the triplet state T1. The resulting polaron pair, the

Charge transport in organic nanocrystal diodes based on rolled-up robust nanomembrane contacts

• Vineeth Kumar Bandari,
• Lakshmi Varadharajan,
• Longqian Xu,
• Abdur Rehman Jalil,
• Mirunalini Devarajulu,
• Pablo F. Siles,
• Feng Zhu and
• Oliver G. Schmidt

Beilstein J. Nanotechnol. 2017, 8, 1277–1282, doi:10.3762/bjnano.8.129

• heterojunction nanopyramids, three kinds of organic nanopyramids were grown on well-defined bottom Au finger electrodes (Au mesa), i.e., pure VOPc (10 nm), F16CuPc (1 nm)/VOPc (9 nm) and F16CuPc (1 nm)/VOPc (8 nm)/F16CuPc (1 nm). The thicknesses are the nominal values detected by the thickness monitor. However

• the charge transport properties of the crystalline nanopyramids, an electrical characterization is performed by measuring the current–voltage (I–V) characteristics. As shown in Figure 2a, the strong charge transfer (CT) between VOPc and F16CuPc causes the heterojunction nanopyramids with double

ZnO nanoparticles sensitized by CuInZn_xS_2+x quantum dots as highly efficient solar light driven photocatalysts

• Florian Donat,
• Serge Corbel,
• Halima Alem,
• Steve Pontvianne,
• Lavinia Balan,
• Ghouti Medjahdi and
• Raphaël Schneider

Beilstein J. Nanotechnol. 2017, 8, 1080–1093, doi:10.3762/bjnano.8.110

• nanoparticles exhibit a high photocatalytic activity under simulated solar light irradiation for the degradation of Orange II dye (>95% degradation after 180 min of irradiation at an intensity of 5 mW/cm2). The heterojunction built between the ZnO nanoparticle and ZCIS QDs not only extends the light adsorption

• . The activity of the ZnO/ZCIS composite is retained at over 90% of its original value after ten successive photocatalytic runs, indicating its high stability and its potential for practical photocatalytic applications. Keywords: heterojunction; photocatalysis; quantum dots; reactive oxygen species

• heterojunction between ZnO nanoparticles and ZCIS QDs. Photocatalytic performance test A 100 mL Pyrex glass flask was used as a batch reactor. All experiments were performed at ambient temperature (20 ± 2 °C). In a typical photocatalytic experiment, 30 mg of the ZnO/ZCIS catalyst were added to 50 mL of an

High photocatalytic activity of Fe₂O₃/TiO₂ nanocomposites prepared by photodeposition for degradation of 2,4-dichlorophenoxyacetic acid

• Shu Chin Lee,
• Hendrik O. Lintang and
• Leny Yuliati

Beilstein J. Nanotechnol. 2017, 8, 915–926, doi:10.3762/bjnano.8.93

• photodeposition showed higher photocatalytic activity than the unmodified TiO2. Three times higher photocatalytic activity was obtained on the best photocatalyst, Fe2O3(0.5)/TiO2. The improved activity of TiO2 after photodeposition of Fe2O3 was contributed to the formation of a heterojunction between the Fe2O3

• stability and reusability, suggesting its potential for water purification applications. Keywords: 2,4-dichlorophenoxyacetic acid; Fe2O3/TiO2; herbicide degradation; heterojunction; holes and superoxide radicals; photocatalyst; photodeposition; water purification; Introduction Photocatalytic reactions

• , the possible formation of a heterojunction between Fe2O3 and TiO2 was considered. Such close contact would cause the carrier diffusion length to be short, and in turn, would improve the charge transfer. This would thus suppress charge recombination, which is crucial to enhance the photocatalytic

Analysis and modification of defective surface aggregates on PCDTBT:PCBM solar cell blends using combined Kelvin probe, conductive and bimodal atomic force microscopy

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

Beilstein J. Nanotechnol. 2017, 8, 579–589, doi:10.3762/bjnano.8.62

• the majority of modern PSCs consist of nanoscale bulk heterojunction (BHJ) structures [7], changes in the internal structures, such as local crystallization of polymers or phase separation of donor and acceptor mixtures, greatly affect the device performance [8][9]. Extensive research has been

Role of oxygen in wetting of copper nanoparticles on silicon surfaces at elevated temperature

• Tapas Ghosh and
• Biswarup Satpati

Beilstein J. Nanotechnol. 2017, 8, 425–433, doi:10.3762/bjnano.8.45

• higher theoretical photocurrent density [23]. The practical conversion efficiency for CuO is low, which may be due to its low carrier concentration [24]. Again, the p-type CuO–n-type Si heterojunction is applicable for solar cells due to their similar electron affinity [25]. The reported open circuit

• voltage for a p-CuO/n-Si heterojunction solar cell is 0.33 V [26] and after improving the crystalline quality and the interface quality between the CuO and the Si, an increased open circuit voltage of 0.509 V and a high photocurrent density of 12 mA/cm2 have been achieved [25]. Therefore, it is important

• formation by the thermal oxidation of Cu nanoparticles on the silicon surface leads to the wetting. Such wetting implies a strong interaction between the CuO and the SiO2/Si surfaces. This study may be useful to understand and improve the efficiency of p-CuO/n-Si heterojunction solar cells. Plan view (a

Nanocrystalline TiO₂/SnO₂ heterostructures for gas sensing

• Barbara Lyson-Sypien,
• Anna Kusior,
• Mieczylaw Rekas,
• Jan Zukrowski,
• Marta Gajewska,
• Katarzyna Michalow-Mauke,
• Thomas Graule,
• Marta Radecka and
• Katarzyna Zakrzewska

Beilstein J. Nanotechnol. 2017, 8, 108–122, doi:10.3762/bjnano.8.12

• an n–n heterojunction, b) electron transfer from a TiO2 to a SnO2 grain providing active gas adsorption sites. EF: Fermi energy, EVB: valence band maximum energy, ECB: conduction band minimum energy, Eg: energy band gap, e−: electron, O−: singly ionized oxygen adatom. Comparison between XRD patterns

Nanostructured TiO₂-based gas sensors with enhanced sensitivity to reducing gases

• Wojciech Maziarz,
• Anna Kusior and
• Anita Trenczek-Zajac

Beilstein J. Nanotechnol. 2016, 7, 1718–1726, doi:10.3762/bjnano.7.164

• electronic structure by improving electron migration from titanium dioxide to tin dioxide and promotes oxygen molecule adsorption at the surface [34]. The as-formed heterojunction (n–n type) affects the response due to the formation of the accumulation/depletion layer and increases the potential barrier at

• carrier transfer occurs and formation of a charge depletion layer. The discrete SnO2 nanoparticle coating acts as an oxygen adsorber, which donates electrons and increases carrier concentration, creating a stronger n–p heterojunction. As a result, tin oxide may become the primary conductive path, which

• sensitive layered sensor to the CO(CH3)2 extremely sensitive flower-like sensor. According to our previous experience in the field of photo-electrochemical properties, the creation of a SnO2–TiO2 heterojunction, whether in the form of SnO2 nanoparticles deposited on the flower-like TiO2 nanostructures

Role of RGO support and irradiation source on the photocatalytic activity of CdS–ZnO semiconductor nanostructures

• Suneel Kumar,
• Rahul Sharma,
• Vipul Sharma,
• Gurunarayanan Harith,
• Vaidyanathan Sivakumar and
• Venkata Krishnan

Beilstein J. Nanotechnol. 2016, 7, 1684–1697, doi:10.3762/bjnano.7.161

• , increasing the photo response range and enhancing the interfacial charge transfer [22]. We have focused our study on the coupling of ZnO nanorods with nanoparticles of CdS, a semiconductor active under visible light, to form coupled CdS–ZnO heterojunction nanostructures. The CdS nanoparticles are an

Scanning probe microscopy studies on the adsorption of selected molecular dyes on titania

• Jakub S. Prauzner-Bechcicki,
• Lukasz Zajac,
• Piotr Olszowski,
• Res Jöhr,
• Antoine Hinaut,
• Thilo Glatzel,
• Bartosz Such,
• Ernst Meyer and
• Marek Szymonski

Beilstein J. Nanotechnol. 2016, 7, 1642–1653, doi:10.3762/bjnano.7.156

• ) islands. Pc molecules There are very few reports available for TiO2 and phthalocyanines in planar heterojunction solar cell applications (see [42] and the references therein). In a few cases among these studies, scanning probe microscopy was used to examine the properties of the Pc/TiO2 interface itself

High-resolution noncontact AFM and Kelvin probe force microscopy investigations of self-assembled photovoltaic donor–acceptor dyads

• Benjamin Grévin,
• Pierre-Olivier Schwartz,
• Laure Biniek,
• Martin Brinkmann,
• Nicolas Leclerc,
• Elena Zaborova and
• Stéphane Méry

Beilstein J. Nanotechnol. 2016, 7, 799–808, doi:10.3762/bjnano.7.71

• elementary building block level. Keywords: donor–acceptor co-oligomers; donor–acceptor lamellae; donor–acceptor-ordered bulk heterojunction; Kelvin probe force microscopy (KPFM); noncontact atomic force microscopy (nc-AFM); organic photovoltaics; surface photo-voltage (SPV); Introduction Nowadays, with

• power conversion efficiency records of over 10% [1][2], solution-processed organic solar cells are regarded as a promising alternative to conventional silicon-based photovoltaic devices. Bulk heterojunction (BHJ) organic solar cells rely on blends of electron-donor (D) and electron-acceptor (A

Synthesis and applications of carbon nanomaterials for energy generation and storage

• Marco Notarianni,
• Jinzhang Liu,
• Kristy Vernon and
• Nunzio Motta

Beilstein J. Nanotechnol. 2016, 7, 149–196, doi:10.3762/bjnano.7.17

• the device. The active layer can be a double layer (one has a stronger affinity for electrons (donor) and the other has a stronger affinity for holes (acceptor)) or a bulk heterojunction (mixture of a donor and acceptor material in bulk). The bulk heterojunction (BHJ) provides a larger volume of paths

Blue and white light emission from zinc oxide nanoforests

• Nafisa Noor,
• Luca Lucera,
• Thomas Capuano,
• Venkata Manthina,
• Alexander G. Agrios,
• Helena Silva and
• Ali Gokirmak

Beilstein J. Nanotechnol. 2015, 6, 2463–2469, doi:10.3762/bjnano.6.255

• heterojunction LEDs [22]. The superposition of electroluminescence and Fabry–Pérot oscillations has also been suggested as the possible mechanism for blue–white emission from ZnO-based homojunction LEDs [23]. The spectra obtained in this work (from a large number of measurements with DC, AC and pulse analyses

• that could be tailored for various applications. Even though many reports on light emission from ZnO refer to solid-state electroluminescence from homojunction or heterojunction structures, our results show that plasma formation can also take place with comparable electric fields and currents and can

Current–voltage characteristics of manganite–titanite perovskite junctions

• Benedikt Ifland,
• Patrick Peretzki,
• Birte Kressdorf,
• Philipp Saring,
• Andreas Kelling,
• Michael Seibt and
• Christian Jooss

Beilstein J. Nanotechnol. 2015, 6, 1467–1484, doi:10.3762/bjnano.6.152

• colossal electro-resistance (CER). For the perovskite heterojunction La0.32Pr0.33Ca0.33MnO3 with 0.5 wt % Nb-doped SrTiO3, the influence of a magnetic field on the temperature-dependent photovoltaic effect was reported [5]. In contrast, STNO has a band gap of around Eg = 3.2 eV [25] and the reported type

• and valence band, respectively, and J0 is nearly independent of the temperature. Heterojunction If two different semiconducting materials are used, for example, a junction made of Ge and GaAs, the device is called a p–n heterostructure. One of the main differences is the presence of discontinuities in

• can be written as Here the partial voltage decrease over semiconductor 1 and 2 is given by V1 and V2. If we consider a p–n heterojunction, where Vbi,1 > ΔEC, there is no barrier for the charge carriers in semiconductor 1 to reach the semiconductor 2 and the equation can be reformulated as with Here

Observation of a photoinduced, resonant tunneling effect in a carbon nanotube–silicon heterojunction

• Carla Aramo,
• Antonio Ambrosio,
• Michelangelo Ambrosio,
• Maurizio Boscardin,
• Paola Castrucci,
• Michele Crivellari,
• Marco Cilmo,
• Maurizio De Crescenzi,
• Francesco De Nicola,
• Emanuele Fiandrini,
• Valentina Grossi,
• Pasqualino Maddalena,
• Maurizio Passacantando,
• Sandro Santucci,
• Manuela Scarselli and
• Antonio Valentini

Beilstein J. Nanotechnol. 2015, 6, 704–710, doi:10.3762/bjnano.6.71

• , Sezione di Bari and Dipartimento di Fisica, Università degli Studi di Bari, Via Amendola 173, 70126 Bari, Italy 10.3762/bjnano.6.71 Abstract A significant resonant tunneling effect has been observed under the 2.4 V junction threshold in a large area, carbon nanotube–silicon (CNT–Si) heterojunction

• obtained by growing a continuous layer of multiwall carbon nanotubes on an n-doped silicon substrate. The multiwall carbon nanostructures were grown by a chemical vapor deposition (CVD) technique on a 60 nm thick, silicon nitride layer, deposited on an n-type Si substrate. The heterojunction

• characteristics were intensively studied on different substrates, resulting in high photoresponsivity with a large reverse photocurrent plateau. In this paper, we report on the photoresponsivity characteristics of the device, the heterojunction threshold and the tunnel-like effect observed as a function 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

• electrochemical methods. Since the polymerization reaction is a very fast process with regards to monomer diffusion along the SiNW, the conformal deposition by classical, fixed potential deposition was not favored. Instead, the core–shell heterojunction structure was finally achieved by a pulsed deposition method

• poly(3,4-ethylenedioxythiophene)/polystyrene sulfonate (PEDOT/PSS) (a successful, commercial, conducting polymer) onto a SiNW array. This gave very promising results for photovoltaic cells based on this heterojunction, with a photon capture efficiency (PCE) of 6.72% [15]. The resulting SiNW/PEDOT/PSS

• heterojunction showed rectification behavior with a large saturation current density. A relatively low shunt resistance and a high saturation current are displayed by devices produced using the spin coating method. This is because the PEDOT:PSS only partially covers the SiNWs array, leaving most of the SiNW

Tm-doped TiO₂ and Tm₂Ti₂O₇ pyrochlore nanoparticles: enhancing the photocatalytic activity of rutile with a pyrochlore phase

• Desiré M. De los Santos,
• Javier Navas,
• Teresa Aguilar,
• Antonio Sánchez-Coronilla,
• Concha Fernández-Lorenzo,
• Rodrigo Alcántara,
• Jose Carlos Piñero,
• Ginesa Blanco and
• Joaquín Martín-Calleja

Beilstein J. Nanotechnol. 2015, 6, 605–616, doi:10.3762/bjnano.6.62

• the recombination of the electron–hole pairs, because the recombination is usually much easier than the subsequent steps required for organic degradation [10]. In our case, the heterojunction that exists at the interface of the mixed phases in the doped samples promotes charge separation, that is, the

Low cost, p-ZnO/n-Si, rectifying, nano heterojunction diode: Fabrication and electrical characterization

• Vinay Kabra,
• Lubna Aamir and
• M. M. Malik

Beilstein J. Nanotechnol. 2014, 5, 2216–2221, doi:10.3762/bjnano.5.230

• Vinay Kabra Lubna Aamir M. M. Malik Nanotechnology Research Laboratory, Centre of Nanoscience and Engineering, Maulana Azad National Institute of Technology, Bhopal 462051, India 10.3762/bjnano.5.230 Abstract A low cost, highly rectifying, nano heterojunction (p-ZnO/n-Si) diode was fabricated

• an n-Si substrate using a dip coating technique. The device was then characterized by current–voltage (I–V) and capacitance–voltage (C–V) measurements. The effect of UV illumination on the I–V characteristics was also explored and indicated the formation of a highly rectifying, nano heterojunction

• other electronic circuitry. Keywords: capacitance–voltage measurements; current–voltage measurement; solution-processed rectifying p-ZnO/n-Si heterojunction diode; UV illumination; Introduction The fabrication of homo- and hetero-junction diodes based on nanomaterials is an emerging field that could

Optical properties and electrical transport of thin films of terbium(III) bis(phthalocyanine) on cobalt

• Peter Robaschik,
• Pablo F. Siles,
• Daniel Bülz,
• Peter Richter,
• Manuel Monecke,
• Michael Fronk,
• Svetlana Klyatskaya,
• Daniel Grimm,
• Oliver G. Schmidt,
• Mario Ruben,
• Dietrich R. T. Zahn and
• Georgeta Salvan

Beilstein J. Nanotechnol. 2014, 5, 2070–2078, doi:10.3762/bjnano.5.215

• TbPc2/Co heterojunction was already proposed to serve as a model system for a SMM semiconducting layer on top of a ferromagnetic electrode for a future spintronic device. The chemical and magnetic properties of this interface were investigated by Klar et al. and it was found that the magnetic moment of

An insight into the mechanism of charge-transfer of hybrid polymer:ternary/quaternary chalcopyrite colloidal nanocrystals

• Parul Chawla,
• Son Singh and
• Shailesh Narain Sharma

Beilstein J. Nanotechnol. 2014, 5, 1235–1244, doi:10.3762/bjnano.5.137

• notable study reports on a combination of poly(2-methoxy-5-(3,7-dimethyloctyloxy)-1,4-phenylene vinylene) (MDMO-PPV) and poly(3-hexylthiophene) (P3HT) with (CISe) and copper indium disulfide (CIS) nanocrystals involving a bulk heterojunction device prepared from copper indium disulfide and p-doped poly

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

• the overall photocatalytic activity. Our work demonstrates that efficient and low cost photocatalytic hydrogen production can be achieved through the substitution of noble metal cocatalyst with a properly engineered surface heterojunction [29]. In addition to the screening for a noble-metal free

• capable of splitting pure water, which provides a new route to the development of nanosized photocatalysts for water splitting [64]. From single heterojunction to long range ordered homojunction Semiconductor heterostructures can be engineered to combine functionalities that result from the bulk

• different sides of the heterojunction. Most type-II heterojunctions have been obtained from two different semiconductors [68][69]. Matching of two semiconductor materials with both their band positions and crystal lattices is the key challenge of this strategy. Most recently, successful efforts have been