Structural, optical and photocatalytic properties of flower-like ZnO nanostructures prepared by a facile wet chemical method

• Sini Kuriakose,
• Neha Bhardwaj,
• Jaspal Singh,
• Biswarup Satpati and
• Satyabrata Mohapatra

Beilstein J. Nanotechnol. 2013, 4, 763–770, doi:10.3762/bjnano.4.87

• Flower-like ZnO nanostructures were synthesized by a facile wet chemical method. Structural, optical and photocatalytic properties of these nanostructures have been studied by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), photoluminescence (PL) and

• spectra of the samples were recorded in the range from 400 to 4000 cm−1. The optical properties of the samples were studied by UV–vis absorption spectroscopy and photoluminescence (PL) spectroscopy at room temperature. The powder samples were dispersed in doubly distilled water by sonication and their

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

• obtained from TEM more accurately. The room temperature photoluminescence (PL) spectra of annealed ZnO nanoparticles are shown in Figure 3a. All the nanoparticle samples show a small UV emission at approx. 355 nm, which can be attributed to the near band edge transitions in the ZnO nanoparticles, and a

• observed, which is reduced gradually to 87.25% in the samples annealed at 350 °C, because of the reduction in the surface defects in the nanoparticles. It was observed earlier in the steady-state photoluminescence study of the annealed ZnO nanoparticles (Figure 3a), that the defect mediated green–yellow

• picosecond-resolved TCSPC studies, it was observed that the energy related to the defect-mediated photoluminescence from the ZnO nanoparticles that peaks at about 530 nm resonantly transfers to the BR molecules adsorbed at the surface via the Förster resonance energy transfer (FRET) process: This leads to an

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

• , 19, Raina Blvd., LV 1586, Riga, Latvia 10.3762/bjnano.4.78 Abstract A study of transmittance and photoluminescence spectra on the growth of oxygen-rich ultra-thin ZnO films prepared by atomic layer deposition is reported. The structural transition from an amorphous to a polycrystalline state is

• photoluminescence emissions correspond to transitions near the band-edge and defect-related transitions. Additional emissions were observed from band-tail states near the edge. A high oxygen ratio and variable optical properties could be attractive for an application of atomic layer deposition (ALD) deposited

• ultrathin ZnO films in optical sensors and biosensors. Keywords: atomic layer deposition; optical properties; photoluminescence; thin films; ZnO; Introduction Zinc oxide (ZnO) is an n-type semiconductor and a transparent conductive oxide (TCO) with excellent optoelectronic properties, a wide band gap

Photocatalytic antibacterial performance of TiO₂ and Ag-doped TiO₂ against S. aureus. P. aeruginosa and E. coli

• Kiran Gupta,
• R. P. Singh,
• Ashutosh Pandey and
• Anjana Pandey

Beilstein J. Nanotechnol. 2013, 4, 345–351, doi:10.3762/bjnano.4.40

• bacterial strains under visible-light irradiation. The TiO2 and Ag-doped TiO2 photocatalysts were synthesized by acid catalyzed sol–gel technique and characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), UV–vis spectroscopy and photoluminescence (PL). The XRD pattern revealed

• and transfer behaviour of the photoexcited electron–hole pairs in the semiconductors was recorded by photoluminescence. The antimicrobial activity of TiO2 and Ag-doped TiO2 nanoparticles (3% and 7%) was investigated against both gram positive (Staphylococcus aureus) and gram negative (Pseudomonas

• acid-catalyzed sol–gel technique. The prepared particles were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), ultraviolet visible spectroscopy (UV–vis) and photoluminescence (PL). Furthermore, the antibacterial activity of the TiO2 and Ag-TiO2 nanoparticles were

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

• Ulrich Herr,
• Balati Kuerbanjiang,
• 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

• , whereas for higher Eu concentrations an increasing fraction of rutile is visible. Optical properties of the materials were determined by photoluminescence spectroscopy in a Fluorolog FL3-22 spectrometer (Jobin Yvon) equipped with a Hamamatsu R928P photomultiplier tube. Excitation and emission spectra were

Photoresponse from single upright-standing ZnO nanorods explored by photoconductive AFM

• Igor Beinik,
• Markus Kratzer,
• Astrid Wachauer,
• Lin Wang,
• Yuri P. Piryatinski,
• Gerhard Brauer,
• Xin Yi Chen,
• Yuk Fan Hsu,
• Aleksandra B. Djurišić and
• Christian Teichert

Beilstein J. Nanotechnol. 2013, 4, 208–217, doi:10.3762/bjnano.4.21

• have also performed time-resolved photoluminescence measurements macroscopically. Results: Persistent photoconductivity from single ZnO NRs was observed for about 1800 s and was studied with the help of photocurrent spectroscopy, which was recorded locally. The photocurrent spectra recorded from single

• ZnO NRs revealed that the minimum photon energy sufficient for photocurrent excitation is 3.1 eV. This value is at least 100 meV lower than the band-gap energy determined from the photoluminescence experiments. Conclusion: The obtained results suggest that the photoresponse in ZnO NRs under ambient

• technique to study the electrical transport in individual upright standing ZnO NRs grown by thermal evaporation [41]. The results obtained together with those of time-resolved photoluminescence (PL) suggest that the photoresponse in ZnO NRs originates preferentially from the photoexcitation of charge

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

• or azimuthally polarized focus. A sharp gold tip (tip radius smaller than 15 nm) is used to scan over the structure, collecting the near-field responses. Notably, the sharp gold tip also gives a strong photoluminescence signal, whose intensity is linearly proportional to the local field strength at

• = 0.998. The detection was performed by confocal microscopy and the collected signal is one-photon photoluminescence. Figure 7 depicts examples of these kinds of measurements on closed and open oligomer ring structures. One observes a strong interaction of the light field with the plasmonic nanostructures

• gold structures show substantial photoluminescence [28][29][30]. For some of the conducted experiments, as discussed above, this phenomenon is beneficial, yet, it turned out to be mostly bothersome. In order to circumvent this problem, we designed oligomer structures consisting of aluminium. The new

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

• due to the total internal reflection at the pillar sidewalls [13][14]. Due to the waveguide nature of pillar resonators, the photoluminescence emission is strongly directional, which results in the efficient collection of radiation with a microscope objective. A broadband light transmission

• planar wavefront, light preferably couples to the symmetric fundamental mode. The entire spectrum of cavity modes is clearly visible in the photoluminescence emission with continuous-wave laser excitation of an ensemble of diamond nanocrystals at a wavelength of 532 nm (Figure 8d). The spectral positions

• photoluminescence emission provides us with one-dimensional spatial resolution along the entrance slit of the spectrometer. For this reason a vertical cut through the center of the calculated two-dimensional mode patterns (Figure 8c) can be compared to the CCD image in Figure 8d. In particular, the fundamental mode

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

• patterns (recall Figure 1b,c). In contrast to radial mode, a bright spot in azimuthal mode is actually not located where it appears to be but somewhere in a radius of 530 nm next to it, considering the azimuthal focus has an intensity minimum in the centre. In addition, the average photoluminescence

• Figure 5b). However, the photoluminescence intensity from Fischer patterns on glass is nearly 15 times stronger. Turning to the Mie theory, we note that the dielectric constant of the medium surrounding the metal nano-particles plays a crucial role in describing its plasmonic resonances. In our case, the

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

• Gilad Gotesman Rahamim Guliamov Ron Naaman Department of Chemical Physics, The Weizmann Institute of Science, Rehovot 76100, Israel 10.3762/bjnano.3.72 Abstract We studied the photoluminescence and time-resolved photoluminescence from self-assembled bilayers of donor and acceptor nanoparticles

• films was investigated when the NPs were linked by different linkers [24]. The linker length and the transfer rate were correlated, indicating tunneling charge transfer mechanisms at short distances and dipole–dipole energy transfer mechanisms at longer distances. In other studies, photoluminescence (PL

The oriented and patterned growth of fluorescent metal–organic frameworks onto functionalized surfaces

• Jinliang Zhuang,
• Jasmin Friedel and
• Andreas Terfort

Beilstein J. Nanotechnol. 2012, 3, 570–578, doi:10.3762/bjnano.3.66

• [2.2.2]­octane), since anthracene-based compounds show interesting luminescent properties, such as photoluminescence and electroluminescence [36][38][39]. In order to obtain highly orientated SURMOFs, we used two SAMs of very high structural quality: The COOH-terminated SAM was formed from 4

• substrates (gold) a modified smart SAGA unit providing an incidence angle of 80° was utilized. SAMs of perdeuterated hexadecanethiol (C16D33SH) on gold were used as background samples for the thin-film FT-IR measurement. Photoluminescence spectra were recorded on a PerkinElmer LS 50B fluorescence

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

• with a large interface area over which a strong electric field would lead to a high probability of exciton dissociation [16]. However, the lack of control over the selection of the CNTs has made their integration with polymers quite unsuccessful so far [17], as recently suggested by photoluminescence

Ultraviolet photodetection of flexible ZnO nanowire sheets in polydimethylsiloxane polymer

• Jinzhang Liu,
• Nunzio Motta and
• Soonil Lee

Beilstein J. Nanotechnol. 2012, 3, 353–359, doi:10.3762/bjnano.3.41

• , as the distance between the (0001) planes is 0.52 nm. The nanowires are 20–60 nm in thickness and tens of microns in length. The high surface-to-volume ratio ensures a large surface adsorbance of gaseous molecules. Figure 2 shows the room-temperature photoluminescence (PL) spectrum of the ZnO

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

• overlapped with the know position of the manipulated QD. The slit width of the monochromator was reduced to allow only light from the laser spot to enter, and the QD photoluminescence was collected. The sample was then translated by 1 μm to a section of the sample that had been cleaned of QDs, and a second

• spectrum was taken from that area. The two corresponding spectra are shown in Figure 3c. Both spectra contain several sharp features between 650 nm and 750 nm arising from photoluminescence (PL) caused by the sapphire substrate and are likely due to chromium ions [19]. The PL spectrum taken on the

• white-light image of several cells. The laser spot can be seen in cell A2; (b) An AFM image of cell B1. The black circle shows a single isolated QD, while the yellow circle indicates an area that has been cleared of QDs; (c) Photoluminescence spectrum from the areas of the cell highlighted in (b) after

Surface functionalization of aluminosilicate nanotubes with organic molecules

• Wei Ma,
• Weng On Yah,
• Hideyuki Otsuka and
• Atsushi Takahara

Beilstein J. Nanotechnol. 2012, 3, 82–100, doi:10.3762/bjnano.3.10

• spacers consisting of –CH2CH2– and P=O(OH)2 (Scheme 1). Thiophene oligomers have been extensively studied in recent years due to their excellent optic properties. It has been reported that thiophene oligomers exhibit high quantum yields of photoluminescence, both in solution as well as the solid state

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

Template-assisted formation of microsized nanocrystalline CeO₂ tubes and their catalytic performance in the carboxylation of methanol

• Jörg J. Schneider,
• Meike Naumann,
• Christian Schäfer,
• Armin Brandner,
• Heiko J. Hofmann and
• Peter Claus

Beilstein J. Nanotechnol. 2011, 2, 776–784, doi:10.3762/bjnano.2.86

• diameter of ca. 0.75 µm, composed of nanocrystalline agglomerated ceria particles were thus obtained. The 1-D ceramic ceria material was characterized by X-ray diffraction, scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), UV–vis and photoluminescence

• the PMMA polymer template and thus a denser material deposition of the ceria sol. Photoluminescence (PL) measurements (Figure 10, excitation wavelength 325 nm) reveal a maximum at 415 nm [23]. The strong emission of CeO2 at this wavelength is related to abundant defects such as dislocations, which are

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

• experiments, dye N719 was replaced by a fluorescent dye, namely Coumarin 343 (C343). Similar to dye N719, the carboxylic group of C343 binds directly to the Zn atoms on the surface of the ZnO nanorods [28] and has been used in DSSC applications [29][30]. The steady-state photoluminescence (PL) spectra of the

• USB4000 detector. Steady-state emission spectra were measured with a Jobin Yvon Fluoromax-3 fluorimeter (pump power at 320 nm is ~22 μW/cm2). Each of the photoluminescence transients was measured by the picosecond-resolved time-correlated single-photon counting (TCSPC) technique, with a commercially

• (MCP-PMT, Hammamatsu) was used to detect the photoluminescence from the sample after dispersion through a monochromator. For all transients, the polarizer on the emission side was adjusted to be at 55° (the “magic angle”) with respect to the polarization axis of the excitation beam. Measurements of the

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

• Abstract We report a single molecule detection scheme to investigate excitation spectra of single emitters at room temperature. We demonstrate the potential of single emitter photoluminescence excitation spectroscopy by recording excitation spectra of single CdSe nanocrystals over a wide spectral range of

• molecule absorbance spectrum at room temperature has not yet been reported. A complementary approach to access the frequency dependent coupling of an emitter to an external electromagnetic field is based on photoluminescence excitation spectroscopy. Single emitter photoluminescence excitation microscopy

• wavelength over a broad range. Hence, increased photoluminescence intermittency for certain excitation wavelengths will result in systematically reduced emission intensity for this wavelength in our study. We therefore calculated the sum of the photoluminescence excitation spectra from all single quantum

Dense lying self-organized GaAsSb quantum dots on GaAs for efficient lasers

• Thomas H. Loeber,
• Dirk Hoffmann and
• Henning Fouckhardt

Beilstein J. Nanotechnol. 2011, 2, 333–338, doi:10.3762/bjnano.2.39

• the growth of dense lying dots with a density at least up to 6.5 × 1010 cm−2 and a diameter and height of 20 and 4 nm, respectively. The photoluminescence (PL) spectra revealed a QD peak at an emission wavelength between λ = 0.876 and 1.035 μm, depending on the exact conditions. Using a stack of such

• ]. These samples were grown at a temperature of T ≈ 500 °C. So far, photoluminescence (PL) signals of SK-grown GaSb QDs on GaAs have emerged at a wavelength between 1.0 and 1.3 µm [7][9]. The interface between the GaAs buffer and the GaSb QDs can cause a wetting layer, which will lead to an additional PL

Room temperature synthesis of indium tin oxide nanotubes with high precision wall thickness by electroless deposition

• Mario Boehme,
• Emanuel Ionescu,
• Ganhua Fu and
• Wolfgang Ensinger

Beilstein J. Nanotechnol. 2011, 2, 119–126, doi:10.3762/bjnano.2.14

• dichloromethane. Energy dispersive X-ray (EDX) analysis was performed to determine the elemental composition. The chemical composition of the ITO-NTs was analyzed by X-ray photoelectron spectroscopy (XPS) using monochromatic Al Kα radiation (hν = 1486.6 eV). In addition to the XPS analysis, photoluminescence was

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

• resulting nanocomposites show high transparency of up to 93%. A photoluminescence quantum efficiency of 70% was obtained, with an optimum combination of nanorod (0.05 wt %) and at a UV-initiator concentration of 0.1 wt % for poly(lauryl methacrylate). Nanorods tend to agglomerate in cellulose triacetate

• 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

• have fabricated highly transparent nanocomposites. The PL spectra in Figure 6b show an increase of emission intensity as a function of NR concentration, and a small red shift of ~3 nm from 632 nm for low to 635 nm for high NR concentrations. From photoluminescence (PL) quantum efficiency (QE

Enhanced visible light photocatalysis through fast crystallization of zinc oxide nanorods

• Sunandan Baruah,
• Mohammad Abbas Mahmood,
• Myo Tay Zar Myint,
• Tanujjal Bora and
• Joydeep Dutta

Beilstein J. Nanotechnol. 2010, 1, 14–20, doi:10.3762/bjnano.1.3

• in the molecules adsorbed on the surface of defect engineered nanoparticles [21]. Upon excitation of ZnO nanoparticles with high-energy laser pulses at 375 nm in the presence of MB molecules, a quick decay in photoluminescence in the fast-crystallized particulate samples as compared to the