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

• ]. It has been reported that the native defects in the ZnO lattice, mostly the oxygen vacancy sites, play an important role in the photocatalytic activity of the nanostructures [11]. Oxygen vacancies have been reported as the cause of the characteristic green luminescence of ZnO [12][13][14]. These

• deep-level trap state (VO++) as the origin of the green luminescence. Whereas Vanheusden et al. [29] reported that the recombination of an electron from a VO+ state to a valence band hole lead to the green luminescence peak. In contrast, J. D. Ye et al. [27] has reported that both the above assumptions

• are correct and demonstrated that the broad green–yellow luminescence from ZnO is mainly composed of two individual emission bands centered at approx. 520 and approx. 590 nm respectively, as shown in Figure 3b. It was observed that with increasing annealing temperature the green–yellow emission from

Evolution of microstructure and related optical properties of ZnO grown by atomic layer deposition

• Adib Abou Chaaya,
• Roman Viter,
• Mikhael Bechelany,
• Zanda Alute,
• Donats Erts,
• Anastasiya Zalesskaya,
• Kristaps Kovalevskis,
• Vincent Rouessac,
• Valentyn Smyntyna and
• Philippe Miele

Beilstein J. Nanotechnol. 2013, 4, 690–698, doi:10.3762/bjnano.4.78

• 1 nm steps over the 300–1100 nm range, and photoluminescence in the 370–800 nm range. A solid state LCS-DTL-374QT Nd:YAG 355 nm laser source (Russia) at the intensity of 19 mW/cm2 was used to excite the luminescence. Emission spectra were registered by the experimental setup described by Viter et al

Near-field effects and energy transfer in hybrid metal-oxide nanostructures

• Ulrich Herr,
• Barat Achinuq,
• Cahit Benel,
• Giorgos Papageorgiou,
• Manuel Goncalves,
• Johannes Boneberg,
• Paul Leiderer,
• Paul Ziemann,
• Peter Marek and
• Horst Hahn

Beilstein J. Nanotechnol. 2013, 4, 306–317, doi:10.3762/bjnano.4.34

• Eu fluorescence can be suppressed by covering the nanoantennas with a 10 nm thick SiOx layer. Keywords: confocal microscopy; energy transfer; field enhancement; light harvesting; luminescence; nano-antennas; nanosphere lithography; nanostructures; plasmonics; simulation; TiO2 nanoparticles

Selective surface modification of lithographic silicon oxide nanostructures by organofunctional silanes

• Thomas Baumgärtel,
• Christian von Borczyskowski and
• Harald Graaf

Beilstein J. Nanotechnol. 2013, 4, 218–226, doi:10.3762/bjnano.4.22

• the successful binding. Figure 6 shows a typical fluorescence spectrum from the FITC-terminated structure depicted in Figure 5. A confocal microscope image of the whole structure is displayed in the inset. There is a clear luminescence signal, which originates from the nanostructure only. The spectral

Nanoparticles of novel organotin(IV) complexes bearing phosphoric triamide ligands

• Zahra Shariatinia,
• Ebadullah Asadi,
• Vahid Tavasolinasab and
• Khodayar Gholivand

Beilstein J. Nanotechnol. 2013, 4, 94–102, doi:10.3762/bjnano.4.11

• complexation. Keywords: luminescence; nanoparticles; organotin(IV) complexes; phosphoric triamide; ultrasonic; Introduction In recent years, the increasing progress in the preparation of nanomaterials has led to characterization of a great number of nanostructures [1]. Nanoscale materials are of significance

Plasmonic oligomers in cylindrical vector light beams

• Mario Hentschel,
• Jens Dorfmüller,
• Harald Giessen,
• Sebastian Jäger,
• Andreas M. Kern,
• Kai Braun,
• Dai Zhang and
• Alfred J. Meixner

Beilstein J. Nanotechnol. 2013, 4, 57–65, doi:10.3762/bjnano.4.6

• the plasmonic structures. Experiments and simulation of near-field imaging of plasmonic oligomer rings using gold luminescence We excited the plasmonic oligomer rings with radially and azimuthally polarized light at 632.8 nm. The excitation was performed by utilizing a parabolic mirror with an NA

• , resembling a “magnetic focusing”, featuring a central spot of enhanced intensity with a diameter of ca. 340 nm. The reason for this behavior is as follows: The luminescence signal is generated by the individual gold dots, which in turn have been excited by the external light filed. Thus, the signal strength

• optical microscopes. Oligomer rings composed of gold nanodots, SEM images on the left, confocal luminescence images under azimuthally polarized illumination on the right. Lower row: Simulations based on a planar convolution of the exciting light field with the structure geometry. The left image depicts

Diamond nanophotonics

• Katja Beha,
• Helmut Fedder,
• Marco Wolfer,
• Merle C. Becker,
• Petr Siyushev,
• Mohammad Jamali,
• Anton Batalov,
• Christopher Hinz,
• Jakob Hees,
• Lutz Kirste,
• Harald Obloh,
• Etienne Gheeraert,
• Boris Naydenov,
• Ingmar Jakobi,
• Florian Dolde,
• Sébastien Pezzagna,
• Daniel Twittchen,
• Matthew Markham,
• Daniel Dregely,
• Harald Giessen,
• Jan Meijer,
• Fedor Jelezko,
• Christoph E. Nebel,
• Rudolf Bratschitsch,
• Alfred Leitenstorfer and
• Jörg Wrachtrup

Beilstein J. Nanotechnol. 2012, 3, 895–908, doi:10.3762/bjnano.3.100

• already conducted to produce this center [21][22]. However, the yield of nickel–nitrogen-related centers seems to be rather low. Tungsten is known to produce a family of so-called W5-centers with several luminescence lines near 714 nm [23]. Up to now these centers were only produced by chance in

• polycrystalline diamond samples grown by the hot-filament technique. Accordingly, not much is known about their luminescence properties. Our aim was to produce the W-centers in a well-defined way, in order to enable further studies on these color centers. The goal of our work is the fabrication of stable single

• (1.4035 eV) and 885.12 nm (1.4008 eV), which is in accordance with values known for the 1.4 eV center [16]. CL measurements on the same nickel-doped sample revealed further nickel-related lines. As shown in Figure 13b a luminescence line at a wavelength of 794 nm was detected accompanied by two phonon

Assessing the plasmonics of gold nano-triangles with higher order laser modes

• Laura E. Hennemann,
• Andreas Kolloch,
• Andreas Kern,
• Josip Mihaljevic,
• Johannes Boneberg,
• Paul Leiderer,
• Alfred J. Meixner and
• Dai Zhang

Beilstein J. Nanotechnol. 2012, 3, 674–683, doi:10.3762/bjnano.3.77

• (optical axis of the optical microscope) electric field. We collected and evaluated the emitted luminescence and thereby investigated the respectively excited plasmonic modes. These varied considerably: firstly with the light polarisation in the focus, secondly with the aspect ratio of the triangles and

• position of the triangles with the confocally observed luminescence patterns. Ultimately, we also achieved surface-enhanced Raman spectroscopic studies of adenine molecules adsorbed on such gold nano-triangles. Experimental Our custom-built parabolic mirror based near-field optical microscope has been

• the scattered luminescence coming from the sample. This scattered light is separated from the incoming laser beam by a beam splitter. Subsequently, two consecutive notch filters block the laser wavelength in order to select only the inelastically Stokes scattered light. This signal is finally directed

Combining nanoscale manipulation with macroscale relocation of single quantum dots

• Francesca Paola Quacquarelli,
• Richard A. J. Woolley,
• Martin Humphry,
• Jasbiner Chauhan,
• Philip J. Moriarty and
• Ashley Cadby

Beilstein J. Nanotechnol. 2012, 3, 324–328, doi:10.3762/bjnano.3.36

• manipulated QD is centred at 608 nm, and luminescence at this wavelength is completely absent elsewhere in the cell. The full-width at half-maximum (FWHM) of the QD spectra is 108 meV, which corresponds well to the previously studied emission from single colloidal quantum dots, for which PL blinking was

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

• characteristics of bare ZnO-nanorod and ZnO/Au-nanocomposite DSSCs measured at 1 sun, AM 1.5 G illumination (100 mW/cm2).a Dynamics of picosecond-resolved luminescence transients of C343 dye in the presence and absence of bare ZnO nanorods and ZnO/Au nanocomposites.a J–V characteristics of bare ZnO-nanorod and

Distance dependence of near-field fluorescence enhancement and quenching of single quantum dots

• Volker Walhorn,
• Jan Paskarbeit,
• Heinrich Gotthard Frey,
• Alexander Harder and
• Dario Anselmetti

Beilstein J. Nanotechnol. 2011, 2, 645–652, doi:10.3762/bjnano.2.68

• impact of this relative fluorescence quenching is negligible. Conclusion We presented experimental data and simulations for the fluorescence emission control of single quantum dots by the external intervention of a gold-coated AFM tip. The acquired luminescence data exhibited a nontrivial dependence on

• , respectively. Generally, the shift of the quantum yield can be described in terms of the radiative and nonradiative decay rates (γr, γnr) as follows: The coupling between a dipole emitter and a sharp metallic tip results in an increase of γr [32][35]. Yet, the degree of luminescence enhancement is inherently

• limited by the fluorophore’s intrinsic quantum yield q0, i.e., strong luminescence enhancement can only be observed for low q0 (γnr >> γr). In order to quantify Q, namely the impact of dipolar coupling between the gold tip apex and the fluorophore in the absence of any secondary fields, the detectable

Room temperature excitation spectroscopy of single quantum dots

• Christian Blum,
• Frank Schleifenbaum,
• Martijn Stopel,
• Sébastien Peter,
• Marcus Sackrow,
• Vinod Subramaniam and
• Alfred J. Meixner

Beilstein J. Nanotechnol. 2011, 2, 516–524, doi:10.3762/bjnano.2.56

• molecule detection sensitivity to demonstrate excitation spectra of isolated semiconductor nanocrystals. These fluorophores, often referred to as quantum dots, have unique optical properties [30][31][32][33][34][35], including a narrow and tailored luminescence emission spectrum and significantly enhanced

• than the very photostable quantum dots analyzed in this study. The recorded data further enables the detailed analysis of the influence of the excitation wavelength on the blinking of single quantum dots. Numerous studies on single quantum dots have shown complicated luminescence intermittency, or

Nanophotonics, nano-optics and nanospectroscopy

• Alfred J. Meixner

Beilstein J. Nanotechnol. 2011, 2, 499–500, doi:10.3762/bjnano.2.53

• dimensions much smaller than the wavelength of electromagnetic radiation [7][8][9]. Well-known examples are the negative refractive index created by metamaterials [10][11], the quantum confinement observed in the absorption and luminescence spectra of semiconductor nanoparticles [12], and the plasmon

Fabrication and spectroscopic studies on highly luminescent CdSe/CdS nanorod polymer composites

• Jana Bomm,
• Andreas Büchtemann,
• Angela Fiore,
• Liberato Manna,
• James H. Nelson,
• Diana Hill and
• Wilfried G. J. H. M. van Sark

Beilstein J. Nanotechnol. 2010, 1, 94–100, doi:10.3762/bjnano.1.11

• . Keywords: CdSe; luminescence lifetime; nanocomposites; nanorods; quantum yield; Introduction Semiconductor nanoparticles have attracted great interest in recent years because of their fascinating optical properties. Their emission wavelength can be tuned directly by changing their size and shape as a

• , aggregation of nanoparticles, loss of transparency and luminescence quenching due to exciton energy transfer [2][7]. Several methods have been described to overcome these problems for quantum dot polymer composites. For example, Bawendi and coworkers incorporated trioctylphosphine oxide covered CdSe/ZnS QDs

• thermal polymerization process leads to luminescence quenching and as a result nanocomposites with photoluminescence (PL) quantum efficiency (QE) of less than 40% were obtained [6][7][8]. Here we present two different methods to fabricate nanorod polymer composites: (a) UV-polymerization and (b) a radical