Optimizing the synthesis of CdS/ZnS core/shell semiconductor nanocrystals for bioimaging applications

• Li-wei Liu,
• Si-yi Hu,
• Ying Pan,
• Jia-qi Zhang,
• Yue-shu Feng and
• Xi-he Zhang

Beilstein J. Nanotechnol. 2014, 5, 919–926, doi:10.3762/bjnano.5.105

• QDs. Photoluminescence (PL) decay is an important parameter for the study of the optical and surface chemical properties of nanoparticles. A multi-exponential decay curve provides evidence for the presence of nonradiative and radiative recombination. If the electron–hole pair recombines through the

Biomolecule-assisted synthesis of carbon nitride and sulfur-doped carbon nitride heterojunction nanosheets: An efficient heterojunction photocatalyst for photoelectrochemical applications

• Hua Bing Tao,
• Hong Bin Yang,
• Jiazang Chen,
• Jianwei Miao and
• Bin Liu

Beilstein J. Nanotechnol. 2014, 5, 770–777, doi:10.3762/bjnano.5.89

• lattice spacing for the dark region and the dim region are 0.328 nm and 0.322 nm respectively, which are consistent with the XRD results. The HRTEM image gives solid evidence towards the formation of heterojunction in CN/CNS. Figure 6a shows the photoluminescence (PL) spectra of CN, CNS and a CN/CNS

• . The photoluminescence (PL) spectra were recorded using an LP920-KS instrument from Edinburgh Instruments, equipped with a photomultiplier tube. Photoelectrochemical measurements The photoelectrochemical properties of as-prepared samples were measured by using an electrochemical workstation (CHI 760E

• heterojunction. (a) FESEM image of CN/CNS heterostructure, (b) XRD and (c) nitrogen adsorption–desorption isotherms and (d) pore size distribution (insert) of CN, CNS and CN/CNS heterostructure. TEM (a) and HRTEM (b) images of a CN/CNS heterostructure. (a) Photoluminescence of CN, CNS and CN/CNS in aqueous

Nanostructure sensitization of transition metal oxides for visible-light photocatalysis

• Hongjun Chen and
• Lianzhou Wang

Beilstein J. Nanotechnol. 2014, 5, 696–710, doi:10.3762/bjnano.5.82

• carriers, quantum dots have a unique photoluminescence (PL). In comparison with organic dyes, quantum dots are characterized by unique optical and electronic properties such as a higher PL quantum efficiency, a wide continuous absorption, a narrower PL band, tunable luminescence depending only on their

Enhanced photocatalytic activity of Ag–ZnO hybrid plasmonic nanostructures prepared by a facile wet chemical method

• Sini Kuriakose,
• Vandana Choudhary,
• Biswarup Satpati and
• Satyabrata Mohapatra

Beilstein J. Nanotechnol. 2014, 5, 639–650, doi:10.3762/bjnano.5.75

• microscopy (FESEM), transmission electron microscopy (TEM), photoluminescence (PL) and UV–visible absorption spectroscopy. The effects of citrate concentration and Ag nanoparticle loading on the photocatalytic activity of Ag–ZnO hybrid nanostructures towards sun-light driven degradation of methylene blue (MB

• the background, with an energy slit of 8 eV for Zn, 30 eV for O and 2 eV for Ag. The observed EFTEM images confirmed the decoration of ZnO nanostructures with Ag nanoparticles. Optical absorption and photoluminescence The UV–visible absorption spectra of samples with varying Ag concentration are shown

• and photoluminescence (PL) spectroscopy at room temperature. The powder samples were dispersed in deionized water by sonication and their optical properties were studied by UV–visible absorption spectroscopy by using a dual beam spectrophotometer HITACHI U3300 in the wavelength range of 200–800 nm

Encapsulation of nanoparticles into single-crystal ZnO nanorods and microrods

• Jinzhang Liu,
• Marco Notarianni,
• Llew Rintoul and
• Nunzio Motta

Beilstein J. Nanotechnol. 2014, 5, 485–493, doi:10.3762/bjnano.5.56

• micro-photoluminescence measurement on a single ZnO nanorod containing luminescent nanodiamonds and the spectrum has a different shape from that of naked nanodiamonds, revealing the cavity effect of ZnO nanorod. Keywords: crystal growth; encapsulation; nanoparticles; photoluminescence; ZnO nanorods

• photoluminescence under UV light excitation. Though ZnO micro/nanorods can be both light emitters and optical cavities, the drawback is that their luminescence is not tunable in terms of wavelength and efficiency. For laser applications, the visible emission of ZnO micro/nanocavities has a broad range which can be

• encapsulated. Complete encapsulation of nanoparticles attached to the side facets into the nanorod can be achieved if the newly-grown layer thickness is beyond the nanoparticle size. Micro-photoluminescence of a single ZnO nanorod containing luminescent nanodiamonds The 40 nm size NDs with NV luminescent

Preparation of poly(N-vinylpyrrolidone)-stabilized ZnO colloid nanoparticles

• Tatyana Gutul,
• Emil Rusu,
• Nadejda Condur,
• Veaceslav Ursaki,
• Evgenii Goncearenco and
• Paulina Vlazan

Beilstein J. Nanotechnol. 2014, 5, 402–406, doi:10.3762/bjnano.5.47

• photoluminescence intensity was increased because of the passivation of surface defects in the nanoparticles [7]. Nanohybrid films with resistivity of 108 Ω·cm were obtained by using PVP with molar mass of 400,000 at various Zn2+/PVP ratios [8]. Colloidal solutions of ZnO are obtained by different methods. For

• = 1.5418 Å) in the range of 2θ = 10–80° at room temperature. FTIR absorption spectra were measured with a PerkinElmer Spectrum100 FTIR spectrometer in the spectral range of 650–4000 cm−1 with a resolution of 2 cm−1 at a close-to-normal light incidence on the substrate at room temperature. Photoluminescence

• indicative of high-quality of ZnO nanoparticles in this sample, i.e., the PPV shell effectively passivates the surface defects of ZnO nanoparticles. The photoluminescence spectra of the components of a colloidal ZnO/PVP/methanol solution are shown in Figure 3. The methanol exhibits a broad luminescence

Photoactivation of luminescence in CdS nanocrystals

• Valentyn Smyntyna,
• Bogdan Semenenko,
• Valentyna Skobeeva and
• Nikolay Malushin

Beilstein J. Nanotechnol. 2014, 5, 355–359, doi:10.3762/bjnano.5.40

• are an important class of materials due to the direct connection of their optical and electronic properties with the size of the particles. In particular the photoluminescence spectrum of high-quality nanocrystals extends from the UV to the IR spectral region due to the size-dependence of the energy

• fluorescence enhancement (PFE) [1][2][3][4][5], intermittency or blinking of photoluminescence [6][7][8], and a blue- or red-shift of the exciton PL of nanocrystals [5][9]. Despite the large number of works devoted to the surface interactions in II–IV QDs [2][3][4][5][10] the mechanisms responsible for the

• photoinduced edge photoluminescence. In order to study the conditions that result in a photostimulation of the band radiation with λmax = 480 nm we performed luminescence studies of the samples in vacuum. It has been found that the process observed in vacuum is reversed compared to the process observed in air

Effect of contaminations and surface preparation on the work function of single layer MoS₂

• Oliver Ochedowski,
• Kolyo Marinov,
• Nils Scheuschner,
• Artur Poloczek,
• Benedict Kleine Bussmann,
• Janina Maultzsch and
• Marika Schleberger

Beilstein J. Nanotechnol. 2014, 5, 291–297, doi:10.3762/bjnano.5.32

• plane of molybdenum atoms that are sandwiched between sulfur atoms. The main reason for this is the transition from an indirect (bulk MoS2) to a direct (single layer MoS2) band gap semi-conductor [5]. Single layer MoS2 has a strong photoluminescence signal [5][6][7][8][9] and other interesting

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

• extinction coefficient and high quantum yield of photoluminescence with the wavelength controlled by the QD size. It is very attractive to use QDs as an energy donor in complexes with organic molecules since the conditions for an effective FRET can be quite easily satisfied. For effective functioning of

• example, the photoinduced reversible electron transfer between QD and molecule, and the formation of QD photoluminescence deactivation centers at the place where the molecule is attached to the QD. Chlorin e6 (Ce6) is one of the tetrapyrrole compounds widely used as a photosensitizer. Photophysical

• properties of complexes between QDs and chlorin e6 were discussed in [6][7]. For example, FRET in covalently linked QD-Ce6 conjugates in aqueous solution was demonstrated [6]. A strong quenching of the photoluminescence (PL) of Ce6 was also observed together with significant changes of the PL and absorption

Controlled synthesis and tunable properties of ultrathin silica nanotubes through spontaneous polycondensation on polyamine fibrils

• Jian-Jun Yuan,
• Pei-Xin Zhu,
• Daisuke Noda and
• Ren-Hua Jin

Beilstein J. Nanotechnol. 2013, 4, 793–804, doi:10.3762/bjnano.4.90

• calcination of hybrid nanotubes of LPEI@silica in an N2 atmosphere showed a distinct photoluminescence centered at 540 nm with a maximum excitation wavelength of 320 nm. Furthermore, LPEI@silica hybrid nanotubes were applied to create silica–carbon composite nanotubes by alternative adsorption of ionic

• ammonia under the comparative conditions with using NaOH [37]. This could be attributed to the extreme excess of ammonia relative to the trace of LPEI–H+ adsorbed on substrate, which enables a rapid deprotonation reaction of LPEI–H+ on the substrate. Photoluminescence. It has been known that silica with a

• porous structure can be, after annealing, used as material, which emits visible light [41][42][43][44]. Although the reason of the silica photoluminescence is not clear, it is mainly attributed to the formation of oxygen defects on the SiO2 framework [44]. To examine the photoluminescence properties, the

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,
• 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

• , 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