Study of mesoporous CdS-quantum-dot-sensitized TiO₂ films by using X-ray photoelectron spectroscopy and AFM

• Mohamed N. Ghazzal,
• Robert Wojcieszak,
• Gijo Raj and
• Eric M. Gaigneaux

Beilstein J. Nanotechnol. 2014, 5, 68–76, doi:10.3762/bjnano.5.6

• . Keywords: AFM; CdS; heterojunction; particle size; quantum dots; TiO2; XPS; Introduction To sensitize the photocatalyst TiO2 with cadmium sulfide quantum dots (QDs-CdS) is a well-established concept that is of great relevance in different applications. The most popular of these applications are

Template based precursor route for the synthesis of CuInSe₂ nanorod arrays for potential solar cell applications

• Mikhail Pashchanka,
• Jonas Bang,
• Niklas S. A. Gora,
• Ildiko Balog,
• Rudolf C. Hoffmann and
• Jörg J. Schneider

Beilstein J. Nanotechnol. 2013, 4, 868–874, doi:10.3762/bjnano.4.98

• purity and crystallinity, and a stoichiometric composition of the CISe ternary semiconductor compound. Keywords: CIS; light absorption; nanocasting; nanorod arrays; precursor synthesis; Introduction Polycrystalline heterojunction solar cells with a columnar morphology of the photovoltaic active layer

Optimization of solution-processed oligothiophene:fullerene based organic solar cells by using solvent additives

• Gisela L. Schulz,
• Marta Urdanpilleta,
• Roland Fitzner,
• Eduard Brier,
• Elena Mena-Osteritz,
• Egon Reinold and
• Peter Bäuerle

Beilstein J. Nanotechnol. 2013, 4, 680–689, doi:10.3762/bjnano.4.77

• (UPV/EHU), Plaza de Europa, 1, 20018 Donostia - San Sebastián, Spain 10.3762/bjnano.4.77 Abstract The optimization of solution-processed organic bulk-heterojunction solar cells with the acceptor-substituted quinquethiophene DCV5T-Bu4 as donor in conjunction with PC61BM as acceptor is described. Power

• devices typically display much better performances in photovoltaic cells. Keywords: active layer morphology; comparison vacuum-processed solar cells; maximum solubility; oligothiophene; solar cells; solution-processed bulk heterojunction; solvent additives; Introduction The demand for the development of

• new materials for applications in organic bulk-heterojunction solar cells (BHJSCs) has been growing over the last decade [1][2][3]. In response, the field has been expanding rapidly with the number of new compounds being produced at an increasingly faster rate [3][4][5]. The photoactive layer in

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

• as Ohmic since electrons may tunnel through the ca. 2 nm thin barrier at the interface space charge region [50]. However, the TiO2/SnO2:F contact forms a heterojunction between two wide-bandgap semiconductors, degenerately doped SnO2 and (intrinsic) nc-TiO2. Kron et al. and Levy et al. [51][52

• offset at the heterojunction allows an estimation of the energy barrier. Depending on the front electrode material, this energy barrier varies and consequently the interface contact resistance differs. As a result, the FF of the DSC can be increased with a lower interface energy barrier and a narrower

• , the interface barrier is around 250 mV. Its influence on the DSC performance is not resolved. In the case of dye-sensitized photoelectrodes, three different mechanisms contribute to the measured SPV. First, there is a contribution from the SnO2:F/TiO2 interface, which forms a heterojunction. The band

Photoelectrochemical and Raman characterization of In₂O₃ mesoporous films sensitized by CdS nanoparticles

• Mikalai V. Malashchonak,
• Sergey K. Poznyak,
• Eugene A. Streltsov,
• Anatoly I. Kulak,
• Olga V. Korolik and
• Alexander V. Mazanik

Beilstein J. Nanotechnol. 2013, 4, 255–261, doi:10.3762/bjnano.4.27

• remove surplus Cd2+ and S2− ions from the surface was omitted. When depositing the bulk CdS, the isotype n-In2O3/n-CdS heterojunction with the external narrow-bandgap semiconductor is formed. In contrast to nanoparticles, the space-charge region can be formed in this bulk semiconductor. As can be

• inferred from the photoelectrochemical behaviour of this system (Figure 8, curve 5), its solid-state heterojunction is not a barrier for photogenerated electrons. A distinctive feature of the photocurrent–potential curves of the heterojunction is the sharp shift of the onset potential to a more negative

• heterojunction with external narrow band-gap component. The generation and separation of photoelectrons and photoholes in this case occur primarily in the CdS at the interface with the electrolyte, and the value of the onset potential is determined by the energy position of the conduction-band edge of bulk CdS

Horizontal versus vertical charge and energy transfer in hybrid assemblies of semiconductor nanoparticles

• Gilad Gotesman,
• Rahamim Guliamov and
• Ron Naaman

Beilstein J. Nanotechnol. 2012, 3, 629–636, doi:10.3762/bjnano.3.72

• type of transfer process. Wu et al. studied charge separation in type-II heterojunction assemblies of CdSe–CdTe NPs as a function of linker length [23]. They found that for longer linkers, the charge transfer efficiency is smaller. In another study, photogenerated exciton dissociation in PbS NP thin

Low-temperature synthesis of carbon nanotubes on indium tin oxide electrodes for organic solar cells

• Andrea Capasso,
• Luigi Salamandra,
• Aldo Di Carlo,
• John M. Bell and
• Nunzio Motta

Beilstein J. Nanotechnol. 2012, 3, 524–532, doi:10.3762/bjnano.3.60

• motivation for the replacement of PCBM with CNTs was an expected increase in electron mobility due to ballistic transport in the CNT phase. Besides, microscopic studies proved that in a mixture of P3HT and CNTs, the polymer self-assembles and wraps the carbon nanostructure, generating a bulk heterojunction

• and semiconducting CNTs [21], suggesting that both kinds of nanotubes could ultimately act as hole acceptors. Whatever the solution to this puzzle is, including MWCNTs in a blend of P3HT and PCBM matches the key objective of achieving large interfacial areas within a bulk donor–acceptor heterojunction

• interface. Besides, by taking into consideration an equivalent-circuit diagram for a bulk heterojunction solar cell (Figure 6), we highlight that the CNTs could be also responsible of a quenched recombination both at the dissociation sites (e.g., donor/acceptor interfaces) and near the anode (as a result of

Structural, electronic and photovoltaic characterization of multiwalled carbon nanotubes grown directly on stainless steel

• Luca Camilli,
• Manuela Scarselli,
• Silvano Del Gobbo,
• Paola Castrucci,
• Eric Gautron and
• Maurizio De Crescenzi

Beilstein J. Nanotechnol. 2012, 3, 360–367, doi:10.3762/bjnano.3.42

• silicon substrate plays an important role in the production of electron–hole pairs. Keywords: carbon nanotubes; electronic properties; heterojunction; photovoltaic; stainless steel; Introduction Carbon nanotubes (CNTs) possess unique electronic, mechanical and optical properties that make them

• activity when they are deposited on a crystalline silicon substrate by the airbrush method. We recall that, while several efforts have been devoted to the build-up of photovoltaic devices based on a SWCNT–Si heterojunction, achieving a surprising efficiency of up to 11% [8], just a few works reported the

• ability of MWCNTs to serve as an energy-conversion material [9][10]. In this paper, we build up a simple photovoltaic device based on MWCNT–Si Schottky heterojunction. Photovoltaic measurements for the in-plane and top-down geometries of the device were performed. In particular, we find that the top-down

Junction formation of Cu₃BiS₃ investigated by Kelvin probe force microscopy and surface photovoltage measurements

• Fredy Mesa,
• William Chamorro,
• William Vallejo,
• Robert Baier,
• Thomas Dittrich,
• Alexander Grimm,
• Martha C. Lux-Steiner and
• Sascha Sadewasser

Beilstein J. Nanotechnol. 2012, 3, 277–284, doi:10.3762/bjnano.3.31

• good structural and optical properties [5][6]. Recently, the potential of the Cu3BiS3/In2S3 heterojunction was investigated by surface photovoltage (SPV) and Hall-effect measurements, showing a passivation of surface defect states in the Cu3BiS3 by the In2S3 buffer layer and the formation of a

Self-assembled monolayers and titanium dioxide: From surface patterning to potential applications

• Yaron Paz

Beilstein J. Nanotechnol. 2011, 2, 845–861, doi:10.3762/bjnano.2.94

• ) heterojunction nanowires by a “bottom-up” approach [96]. Here, Au–TiO2–Au nanowires were prepared within nanoholes of anodic aluminum oxide templates. The preparation procedure included the deposition of gold by electroplating, chemisorption of 1,8-octanedithiol (HS–(CH2)8–SH), oxidation of the terminal thiol