Tandem polymer solar cells: simulation and optimization through a multiscale scheme

• Fanan Wei,
• Ligang Yao,
• Fei Lan,
• Guangyong Li and
• Lianqing Liu

Beilstein J. Nanotechnol. 2017, 8, 123–133, doi:10.3762/bjnano.8.13

• , donor/acceptor weight ratio as well as the donor–acceptor distribution in both active layers of the two sub-cells. Finally, employing searching algorithms, we optimized the power conversion efficiency of the tandem polymer solar cells and located the optimal device structure parameters. With the

• . Furthermore, existing evidence suggests that the distribution of donor/acceptor (D/A) in the active layer is critical in determining the final device performance [1][6]. What also must be considered is that the weight ratio between donor and acceptor is another important factor impacting the PCE of tandem

• donor–acceptor distribution. Details of the morphology generation process is available in Supporting Information File 1. The simulated morphology agrees well with that acquired from actual experiments (Supporting Information File 1, Figure S1). Then, the distribution of donor and acceptor materials in

Facile fabrication of luminescent organic dots by thermolysis of citric acid in urea melt, and their use for cell staining and polyelectrolyte microcapsule labelling

• Nadezhda M. Zholobak,
• Anton L. Popov,
• Alexander B. Shcherbakov,
• Nelly R. Popova,
• Mykhailo M. Guzyk,
• Valeriy P. Antonovich,
• Alla V. Yegorova,
• Yuliya V. Scrypynets,
• Inna I. Leonenko,
• Alexander Ye. Baranchikov and
• Vladimir K. Ivanov

Beilstein J. Nanotechnol. 2016, 7, 1905–1917, doi:10.3762/bjnano.7.182

• urea thermolysis. Thus, the resulting O-dot is a set of primary fluorophores bound by covalent or intermolecular (coordination, donor–acceptor, hydrogen) bonds, for example, forming a polymer-like structure [47], so that the particles formed can be identified as clusters of independent fluorophores [19

Preparation of alginate–chitosan–cyclodextrin micro- and nanoparticles loaded with anti-tuberculosis compounds

• Albert Ivancic,
• Fliur Macaev,
• Fatma Aksakal,
• Veaceslav Boldescu,
• Serghei Pogrebnoi and
• Gheorghe Duca

Beilstein J. Nanotechnol. 2016, 7, 1208–1218, doi:10.3762/bjnano.7.112

• ) in molecular systems. The electron density distribution in the frontier orbitals of the enzyme–ligand complexes under study provides information about the donor–acceptor character of the interactions inside the complexes. The electronic structure calculations were carried out with Gaussian 09 using

• was significant for the LUMO (Figure 13b). Atoms of both isoconazole and amino acid residues (Met199, Thr196, Ala198, Ile202, Met161, and Tyr158) contributed to the donor–acceptor interaction. Conclusion The obtained microparticulate and nanoparticulate systems of alginate–chitosan–β-cyclodextrin with

The influence of phthalocyanine aggregation in complexes with CdSe/ZnS quantum dots on the photophysical properties of the complexes

• Irina V. Martynenko,
• Anna O. Orlova,
• Vladimir G. Maslov,
• Anatoly V. Fedorov,
• Kevin Berwick and
• Alexander V. Baranov

Beilstein J. Nanotechnol. 2016, 7, 1018–1027, doi:10.3762/bjnano.7.94

• QD. Thus, the conditions necessary for FRET to occur in QD–tetrapyrrole donor–acceptor pairs can be easily fulfilled. To date, several studies have demonstrated photoexcitation energy transfer in a variety of QD–tetrapyrrole systems by FRET, with efficiencies close to the theoretical limit for the

• donor–acceptor pair under consideration [15][16][17]. However, in many other QD–tetrapyrrole systems real FRET efficiency was significantly lower than was predicted by evaluation of donor–acceptor distance and spectral overlap integral between donor emission and acceptor absorption bands [9][18][19][20

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

• du Loess, BP 84047, 67034 Strasbourg Cedex 2, France, Institut de Chimie et Procédés pour l’Energie, l’Environnement et la santé (ICPEES), Université de Strasbourg, CNRS UMR 7515, ECPM, 25 rue Becquerel, 67087 Strasbourg Cedex 2, France 10.3762/bjnano.7.71 Abstract Self-assembled donor–acceptor

• images with a very high lateral resolution are achieved, which allows for the resolution of local photo-charging contrasts at the scale of single edge-on lamella. This work paves the way for local investigations of the optoelectronic properties of donor–acceptor supramolecular architectures down to the

• 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

Rigid multipodal platforms for metal surfaces

• Michal Valášek,
• Marcin Lindner and
• Marcel Mayor

Beilstein J. Nanotechnol. 2016, 7, 374–405, doi:10.3762/bjnano.7.34

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

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

• through multiple defect levels or because of the optical excitation of materials by the ultraviolet source [21]. Blue light has been previously observed from ZnO-based homojunction LEDs, where it is attributed to donor–acceptor pair recombination in the p-type ZnO layer [10] and also from n-ZnO/p-GaN

Nanostructured surfaces by supramolecular self-assembly of linear oligosilsesquioxanes with biocompatible side groups

• Maria Nowacka,
• Anna Kowalewska and
• Tomasz Makowski

Beilstein J. Nanotechnol. 2015, 6, 2377–2387, doi:10.3762/bjnano.6.244

• observed due to the donor–acceptor character of the functional groups. The texture of supramolecular nanostructures formed by the studied materials on mica was analysed with atomic force microscopy and their specific surface energy was estimated by contact angle measurements. Significant differences in the

• hydrogen bonds (linear catemeric structures) it adheres to mica as clusters of polymeric chains cross-linked by –COOH···HOOC– dimers or amine salts (–COO−NH2+– and –COO−NH3+–). Species P2, P3 and P4, having donor/acceptor NH/NH2 units, can adsorb on mica-CA via formation of complementary hydrogen bonds

• with COOH groups, which results in a change of the surface morphology (Figure 5). P3 bearing GSH units forms different structures than P2 and P4, which can be explained by better accessibility of donor/acceptor units in GSH molecules. Cys-HCl and NAC in P2 and P4 are more hindered by the polymer matrix

A single-source precursor route to anisotropic halogen-doped zinc oxide particles as a promising candidate for new transparent conducting oxide materials

• Daniela Lehr,
• Markus R. Wagner,
• Johanna Flock,
• Julian S. Reparaz,
• Clivia M. Sotomayor Torres,
• Alexander Klaiber,
• Thomas Dekorsy and
• Sebastian Polarz

Beilstein J. Nanotechnol. 2015, 6, 2161–2172, doi:10.3762/bjnano.6.222

• is dominated by a transition at 3.32 eV. This zero-phonon line is repeated by longitudinal optical phonon replicas with an energy spacing of 72 meV. The high intensity of the phonon replicas is characteristic for a strong electron–phonon coupling as it is typically observed for donor acceptor pairs

Thermoelectricity in molecular junctions with harmonic and anharmonic modes

• Bijay Kumar Agarwalla,
• Jian-Hua Jiang and
• Dvira Segal

Beilstein J. Nanotechnol. 2015, 6, 2129–2139, doi:10.3762/bjnano.6.218

• original Aviram–Ratner construction for a donor–acceptor molecular rectifier [5]. Thus, we identify the two states here as “D” and “A”, see Figure 1, and refer to the model as the “D–A junction”. More recently, this construction was employed for exploring vibrational heating and instability under a large

• , represented by a two-state system. The molecular mode may further relax its energy to a phononic thermal reservoir (not depicted here), maintained at temperature Tph. Linear response behavior of the donor–acceptor junction as a function of molecule–metal hybridization with a harmonic mode (full) and an

• temperature T = 300 K. We assumed flat bands with a constant density of states. Linear response behavior of the donor–acceptor junction as a function of gate voltage. (a) Electrical conductance, (b) Seebeck coefficient, (c) electronic thermal conductance, and (d) figure of merit ZT. Parameters are the same as

Electrical characterization of single molecule and Langmuir–Blodgett monomolecular films of a pyridine-terminated oligo(phenylene-ethynylene) derivative

• Henrry M. Osorio,
• Santiago Martín,
• María Carmen López,
• Santiago Marqués-González,
• Simon J. Higgins,
• Richard J. Nichols,
• Paul J. Low and
• Pilar Cea

Beilstein J. Nanotechnol. 2015, 6, 1145–1157, doi:10.3762/bjnano.6.116

• to draw comparisons with the single molecule conductance as well as with other monolayers containing phenylene-ethynylene derivatives incorporating different terminal groups. The results presented here reveal that the strong Au–N donor–acceptor (D–A) bond results in metal–monolayer–metal devices

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

• positively charged, it is attracted towards the ssDNA main chain resulting in strong electrostatic attractive forces between ssDNA phosphate group and DA. Moreover, the two –OH groups in DA possess hydrogen donor/acceptor ability, and hence, compete with the positively charged region of DA for the ssDNA

• detection, except for the absence of T22. Thus, the strength of SWCNT–ssDNA interaction determines the magnitude of the electrical response to the DA and DA–UA mixtures. In addition, the presence of fewer hydrogen donor/acceptor sites in bases C and T could also contribute to the lower magnitude response of

Non-covalent and reversible functionalization of carbon nanotubes

• Antonello Di Crescenzo,
• Valeria Ettorre and
• Antonella Fontana

Beilstein J. Nanotechnol. 2014, 5, 1675–1690, doi:10.3762/bjnano.5.178

• interactions that nanotubes establish with the surrounding medium with semiconducting tubes favoring donor-acceptor interactions [36][37]. Non-covalent interactions and hydrophobicity of CNTs Despite pristine carbon nanotubes possess a π-conjugative structure with a highly hydrophobic surface, they are

Donor–acceptor graphene-based hybrid materials facilitating photo-induced electron-transfer reactions

• Anastasios Stergiou,
• Georgia Pagona and
• Nikos Tagmatarchis

Beilstein J. Nanotechnol. 2014, 5, 1580–1589, doi:10.3762/bjnano.5.170

• readily utilized in applications that are governed by charge-transfer processes, for example, in solar cells. Alternatively, exfoliated graphene has been applied toward the realization of some donor–acceptor hybrid materials with photo- and/or electro-active components. The main body of research regarding

• obtaining donor–acceptor hybrid materials based on graphene to facilitate charge-transfer phenomena, which is reviewed here, concerns the incorporation of porphyrins and phthalocyanines onto graphene sheets. Through illustrative schemes, the preparation and most importantly the photophysical properties of

• some donor–acceptor graphene-based hybrids, will be discussed. Keywords: donor–acceptor; electron-transfer; functionalization; graphene; photophysical properties; Introduction Among the outstanding forms of carbon nanostructures, graphene, a single layer of carbon, is a newly available material

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

• transition between donor–acceptor pairs. In the Pd/ZnO sample, the excitonic band-edge emission completely vanished or was indistinct, while the structured green luminescence band and the transition shift of the emission maximum to higher energies was clearly visible. The second peak at 517 nm increased and

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

• donor and the charge separation mechanism across the donor–acceptor interface from the extent of crystallinity of the chalcopyrite semiconductors (CISe/CIGSe/CZTSe). Quaternary CZTSe chalcopyrites with their high crystallinity and controlled morphology in conjunction with regioregular P3HT polymer is an

• , a charge-separation at donor–acceptor heterojunctions is a key process, which takes center stage in determining the energy conversion efficiency of hybrid photovoltaics. Hybrid solar cells enjoy an advantage of intrinsically high carrier mobility, which is caused by inorganic materials dispersed in

• across the donor–acceptor interface another possible mechanism of charge transportation could be energy transfer, i.e., the Forster resonance energy transfer (FRET) from the donor to the acceptor after excitation, which results in the generation of an exciton in the acceptor. This mechanism, however, can

Morphological characterization of fullerene–androsterone conjugates

• Alberto Ruiz,
• Margarita Suárez,
• Nazario Martin,
• Fernando Albericio and
• Hortensia Rodríguez

Beilstein J. Nanotechnol. 2014, 5, 374–379, doi:10.3762/bjnano.5.43

• stacking interactions, and donor–acceptor interactions. The aggregation behavior of these compounds was associated to the hydrophobic nature of the C60 core as the main attractive force, furthermore, the presence of different polar groups, carbonyl and acetoxy group for Ia,b and IIa,b respectively, in the

Energy transfer in complexes of water-soluble quantum dots and chlorin e6 molecules in different environments

• Irina V. Martynenko,
• Anna O. Orlova,
• Vladimir G. Maslov,
• Alexander V. Baranov,
• Anatoly V. Fedorov and
• Mikhail Artemyev

Beilstein J. Nanotechnol. 2013, 4, 895–902, doi:10.3762/bjnano.4.101

• In the Förster formalism, a distance dependence of the efficiency of FRET between the donor–acceptor (D–A) pair, QFRET, is given with [13]: where R0 (Förster radius) is the D–A distance at which the transfer efficiency is 50%, and R is the D–A distance. R0 can be calculated using the following

• upper limit of the FRET efficiency for the donor–acceptor pair in the complexes. The energy transfer efficiency from donor to acceptor, , can be correctly estimated from the experimental data on the sensitized acceptor emission intensity [14][15], or the PL QY by using the following equation: where ΦDA

Spin relaxation in antiferromagnetic Fe–Fe dimers slowed down by anisotropic Dy^III ions

• Valeriu Mereacre,
• Frederik Klöwer,
• Yanhua Lan,
• Rodolphe Clérac,
• Juliusz A. Wolny,
• Volker Schünemann,
• Christopher E. Anson and
• Annie K. Powell

Beilstein J. Nanotechnol. 2013, 4, 807–814, doi:10.3762/bjnano.4.92

• experimentally. By using Mössbauer spectroscopy we have shown how minor changes in the electronegativity of the atoms in the ligand sphere and in the donor–acceptor nature of the substituents, and their position on the aromatic ring, can control the shape anisotropy of the DyIII ions and, thus, their interaction

Modulation of defect-mediated energy transfer from ZnO nanoparticles for the photocatalytic degradation of bilirubin

• Tanujjal Bora,
• Karthik K. Lakshman,
• Soumik Sarkar,
• Abhinandan Makhal,
• Samim Sardar,
• Samir K. Pal and
• Joydeep Dutta

Beilstein J. Nanotechnol. 2013, 4, 714–725, doi:10.3762/bjnano.4.81

• smaller than 1 nm. On the other hand, the energy transfer of the Förster mechanism is highly influenced by the Förster distance (R0) and the relative orientation of the transition dipoles of the donor and acceptor in space. Furthermore, the energy exchange occurs within a minimal donor–acceptor distance

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

• efficient electron transfer at the donor–acceptor interface in the photoactive blend layer [36][37]. Moreover, the deep HOMO level, which is typically observed for acceptor-substituted oligothiophenes [32], implied that the Voc of the solar cell device should be quite high. Using the following empirical

• the solar cell performance dependence on the donor–acceptor ratio is summarized in Table S2 in Supporting Information File 1. Figure 4 demonstrates the dependence of the power conversion efficiency on the CN content in CB. From 0 to 0.375% CN, the PCE increased from 2.1% to a maximum value of 3.0

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

• result, surprising distance-dependent transfer rates from the donors to the acceptors were observed, in which the transfer rate increases with the donor–acceptor distance. The electron-transfer process in such hybrid organic–inorganic devices depends of course on the NPs, but also on the linker molecules

• ) and PL-lifetime measurements of donor–acceptor NP bilayers, separated by polyelectrolyte layers, revealed that the energy transfer rate is inversely related to the distance. This is consistent with Förster’s theory for the dipole–dipole energy transfer mechanism in the donor–acceptor bilayers [25][26

• observed linker-length dependency is counterintuitive. The theoretical distance (r)-dependent transfer rates for energy and charge transfer, in donor–acceptor systems, are well known [19][35][36][37][38]. The energy transfer rate, kET, in the case of the Förster mechanism (also referred to as FRET-dipole

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

• 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