Photoluminescence of CdSe/ZnS quantum dots in nematic liquid crystals in electric fields

• Margarita A. Kurochkina,
• Elena A. Konshina and
• Daria Khmelevskaia

Beilstein J. Nanotechnol. 2018, 9, 1544–1549, doi:10.3762/bjnano.9.145

• matrix without reorientation of the LC molecules. With increasing electric field strength, the quenching of QDs luminescence occurred in the active LC matrix, while the PL intensity did not change in the passive LC matrix. The change in the decay time with increasing electric field strength was similar

• to the behavior of the PL intensity. The observed buildup in the QDs luminescence can be associated with the transfer of energy from LC molecules to QDs. In a confocal microscope, we observed the increase of particle size and the redistribution of particles in the active LC matrix with the change of

• the electric field strength. At the same time, no significant changes occurred in the passive LC matrix. With the reorientation of LC molecules from the planar in vertical position in the LC active matrix, quenching of QD luminescence and an increase of the ion current took place simultaneously. The

Absence of free carriers in silicon nanocrystals grown from phosphorus- and boron-doped silicon-rich oxide and oxynitride

• Daniel Hiller,
• Julian López-Vidrier,
• Keita Nomoto,
• Michael Wahl,
• Wolfgang Bock,
• Tomáš Chlouba,
• František Trojánek,
• Sebastian Gutsch,
• Margit Zacharias,
• Dirk König,
• Petr Malý and
• Michael Kopnarski

Beilstein J. Nanotechnol. 2018, 9, 1501–1511, doi:10.3762/bjnano.9.141

• samples were annealed for 1 h in ultra-pure N2 in a quartz tube furnace at 1100 °C (SRO) and 1150 °C (SRON). The thicknesses of the Si-rich oxide layers determine the mean size of the Si NCs to be of approximately the size of the initial layer thickness. Samples dedicated to luminescence and electrical

• probabilities, allowing the luminescence quantum yield to reach ≈30% [36][37], or even ≈60% for organically-capped NCs [38]. In the presence of a third charge carrier (a free electron from an ionized P-donor or a hole from an ionized B-acceptor) radiative recombination is very unlikely, since ultra-fast non

Room-temperature single-photon emitters in titanium dioxide optical defects

• Kelvin Chung,
• Yu H. Leung,
• Chap H. To,
• Aleksandra B. Djurišić and
• Snjezana Tomljenovic-Hanic

Beilstein J. Nanotechnol. 2018, 9, 1085–1094, doi:10.3762/bjnano.9.100

• again, works on defects in TiO2 have been scarce. While some works have associated visible luminescence with specific defects [67], the obtained emission spectra are very broad, covering the entire visible spectral range. At this stage, we cannot attribute a particular defect to the three bands observed

Electro-optical interfacial effects on a graphene/π-conjugated organic semiconductor hybrid system

• Karolline A. S. Araujo,
• Luiz A. Cury,
• Matheus J. S. Matos,
• Thales F. D. Fernandes,
• Luiz G. Cançado and
• Bernardo R. A. Neves

Beilstein J. Nanotechnol. 2018, 9, 963–974, doi:10.3762/bjnano.9.90

• packing and/or ordering [7]. Previous works have demonstrated that intermolecular interactions can dramatically reduce the luminescence quantum yield in solid-state devices [8][9][10][11][12][13]. In this context, it is important to control the ordering of π-conjugated organic molecules to make their use

Facile chemical routes to mesoporous silver substrates for SERS analysis

• Elina A. Tastekova,
• Alexander Y. Polyakov,
• Anastasia E. Goldt,
• Alexander V. Sidorov,
• Alexandra A. Oshmyanskaya,
• Irina V. Sukhorukova,
• Dmitry V. Shtansky,
• Wolgang Grünert and
• Anastasia V. Grigorieva

Beilstein J. Nanotechnol. 2018, 9, 880–889, doi:10.3762/bjnano.9.82

• spectroscopy of rhodamine 6G (R6G) was performed using 5 μL droplets and the concentration range of the analyte was 10−8–10−6 M. The corresponding Raman spectra for R6G deposited onto pristine silver oxide samples contained no signal from the model analyte but only noisy background, indicating luminescence

Perfusion double-channel micropipette probes for oxygen flux mapping with single-cell resolution

• Yang Gao,
• Bin Li,
• Riju Singhal,
• Adam Fontecchio,
• Ben Pelleg,
• Zulfiya Orynbayeva,
• Yury Gogotsi and
• Gary Friedman

Beilstein J. Nanotechnol. 2018, 9, 850–860, doi:10.3762/bjnano.9.79

• oxygen concentration over time as various sequences of mitochondrial modulators and substrates are added to the cell suspension [24][25]. Recent work using oxygen sensing, based on quenching of luminescence due to oxygen, has demonstrated the capability to carry out respirometry on single cells in sealed

Synthesis and characterization of two new TiO₂-containing benzothiazole-based imine composites for organic device applications

• Anna Różycka,
• Agnieszka Iwan,
• Krzysztof Artur Bogdanowicz,
• Michal Filapek,
• Natalia Górska,
• Damian Pociecha,
• Marek Malinowski,
• Patryk Fryń,
• Agnieszka Hreniak,
• Jakub Rysz,
• Paweł Dąbczyński and
• Monika Marzec

Beilstein J. Nanotechnol. 2018, 9, 721–739, doi:10.3762/bjnano.9.67

• conversion efficiency, lifetime) and luminescence parameters (e.g., quantum yield, lifetime) [7][8][9][10][11][12][13][14]. In recent years, the efficiency of bulk heterojunction organic solar cells has shown great improvement, from 2.5 to 13%. Such rapid progress brings us closer to actual commercialization

Green synthesis of fluorescent carbon dots from spices for in vitro imaging and tumour cell growth inhibition

• Nagamalai Vasimalai,
• Vânia Vilas-Boas,
• Juan Gallo,
• María de Fátima Cerqueira,
• Mario Menéndez-Miranda,
• José Manuel Costa-Fernández,
• Lorena Diéguez,
• Begoña Espiña and
• María Teresa Fernández-Argüelles

Beilstein J. Nanotechnol. 2018, 9, 530–544, doi:10.3762/bjnano.9.51

• months without any loss of their optical properties. Typically, C-dots exhibit an interesting excitation-dependent photoluminescence, entirely different from other luminescent materials such as semiconductor quantum dots, gold or silver nanoclusters. This luminescence is attributed to defect states of

Influence of the preparation method on the photocatalytic activity of Nd-modified TiO₂

• Patrycja Parnicka,
• Paweł Mazierski,
• Tomasz Grzyb,
• Wojciech Lisowski,
• Ewa Kowalska,
• Bunsho Ohtani,
• Adriana Zaleska-Medynska and
• Joanna Nadolna

Beilstein J. Nanotechnol. 2018, 9, 447–459, doi:10.3762/bjnano.9.43

• (SHT) methods. The as-prepared samples were characterized by X-ray diffraction (XRD), BET surface area measurements, scanning electron microscopy (SEM), diffuse reflectance spectroscopy (DRS), luminescence spectroscopy and X-ray photoelectron spectroscopy (XPS). The photocatalytic activity of the

• , we presented experimental studies concerning the effect of synthesis methods on lanthanide-modified TiO2. In these studies we compared hydrothermal and sol–gel method. The synthesis method significantly affects the structure, optical, luminescence and photocatalytic properties. It was found that all

• samples (TiO2 modified with Y3+, Pr3+, Er3+ and Eu3+) obtained through the hydrothermal method approach exhibited a higher photocatalytic activity, while the samples prepared via the sol–gel method approach yielded more luminescence when irradiated with 980 nm photons [24]. Meanwhile, the hydrothermal

Sugarcane juice derived carbon dot–graphitic carbon nitride composites for bisphenol A degradation under sunlight irradiation

• Lan Ching Sim,
• Jing Lin Wong,
• Chen Hong Hak,
• Jun Yan Tai,
• Kah Hon Leong and
• Pichiah Saravanan

Beilstein J. Nanotechnol. 2018, 9, 353–363, doi:10.3762/bjnano.9.35

• with previous reports [4][56]. Although the origin of the PL luminescence in CDs is not fully elucidated, the excitation-dependent PL behavior of CDs is usually correlated to the size distribution of CDs, the recombination of photogenerated charges at surface-confined defect states and the different

Dopant-stimulated growth of GaN nanotube-like nanostructures on Si(111) by molecular beam epitaxy

• Alexey D. Bolshakov,
• Alexey M. Mozharov,
• Georgiy A. Sapunov,
• Igor V. Shtrom,
• Nickolay V. Sibirev,
• Vladimir V. Fedorov,
• Evgeniy V. Ubyivovk,
• Maria Tchernycheva,
• George E. Cirlin and
• Ivan S. Mukhin

Beilstein J. Nanotechnol. 2018, 9, 146–154, doi:10.3762/bjnano.9.17

• a helium closed cycle cryostat. PL was excited using a HeCd laser with a wavelength of 325 nm and detected using a PMI Hamamatsu R298 detector. The power density of the laser excitation was 10 W/cm2. The analysis of the PL spectra shows that no yellow luminescence occurs in our samples, indicating

Co-reductive fabrication of carbon nanodots with high quantum yield for bioimaging of bacteria

• Jiajun Wang,
• Xia Liu,
• Gesmi Milcovich,
• Tzu-Yu Chen,
• Edel Durack,
• Sarah Mallen,
• Yongming Ruan,
• Xuexiang Weng and
• Sarah P. Hudson

Beilstein J. Nanotechnol. 2018, 9, 137–145, doi:10.3762/bjnano.9.16

• and urea during the one-pot synthesis enhances the luminescence of the generated C-dots. Moreover, the prepared C-dots have a high distribution of functional groups on their surface. In this work, C-dots proved to be a suitable nanomaterial for imaging of bacteria and exhibit potential for application

PTFE-based microreactor system for the continuous synthesis of full-visible-spectrum emitting cesium lead halide perovskite nanocrystals

• Chengxi Zhang,
• Weiling Luan,
• Yuhang Yin and
• Fuqian Yang

Beilstein J. Nanotechnol. 2017, 8, 2521–2529, doi:10.3762/bjnano.8.252

• , Lexington, KY 40506, USA 10.3762/bjnano.8.252 Abstract Colloidal perovskite nanocrystals comprised of all inorganic cesium lead halide (CsPbX3, X = Cl, Br, I or a mixture thereof) have potential as optical gain materials due to their high luminescence efficiency. In this work, cesium lead halide

• been reported that colloidal, all-inorganic (CsPbX3, X = Cl, Br, I and their mixture thereof) perovskite QDs possess high luminescence efficiency. Reacting Cs-oleate with a Pb(II)-halide in a high boiling solvent (octadecene) at 140–200 °C, Kovalenko et al. [18] prepared CsPbX3 QDs with four edge

• different shapes: spheres, cubes, and rods. This work describes a new route for the continuous synthesis of CsPbX3 nanocrystals with luminescence over the whole visible spectral region and demonstrates that inorganic perovskite nanocrystals have potential applications that span a wide gamut from displays to

Substrate and Mg doping effects in GaAs nanowires

• Perumal Kannappan,
• Nabiha Ben Sedrine,
• Jennifer P. Teixeira,
• Maria R. Soares,
• Bruno P. Falcão,
• Maria R. Correia,
• Nestor Cifuentes,
• Emilson R. Viana,
• Marcus V. B. Moreira,
• Geraldo M. Ribeiro,
• Alfredo G. de Oliveira,
• Juan C. González and
• Joaquim P. Leitão

Beilstein J. Nanotechnol. 2017, 8, 2126–2138, doi:10.3762/bjnano.8.212

• measurements as a function of excitation power and temperature on a bunch of nanowires. In Supporting Information File 1, we present all PL spectra measured for both samples. It is important to mention that no significant influence from the epilayer is expected on the nanowire related luminescence, because no

• intensities are quite different. However, the peak position of C2 and C3 exhibit a slight blue-shift of ≈20 meV for sample A compared to sample B, showing comparable relative intensities. The luminescence in sample A is dominated by a transition at ≈1.481 eV (C4) whereas the PL spectrum in sample B is

• . On the other hand, the low number of experimental points for C2 and C4 hinders a deep discussion of their behavior. Secondly, the luminescence from samples A and B was observed up to 200 K and to room temperature, respectively. However, the behavior of each component is quite different. In the case

Growth and characterization of textured well-faceted ZnO on planar Si(100), planar Si(111), and textured Si(100) substrates for solar cell applications

• Chin-Yi Tsai,
• Jyong-Di Lai,
• Shih-Wei Feng,
• Chien-Jung Huang,
• Chien-Hsun Chen,
• Fann-Wei Yang,
• Hsiang-Chen Wang and
• Li-Wei Tu

Beilstein J. Nanotechnol. 2017, 8, 1939–1945, doi:10.3762/bjnano.8.194

• (LPCVD) were analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM), and cathode luminescence (CL) measurements. The results show that ZnO grown on planar Si(100), planar Si(111), and textured Si(100) substrates favor the growth of ZnO(110) ridge-like, ZnO

• . Keywords: atomic force microscopy; cathode luminescence; scanning electron microscopy; silicon solar cells; transparent conducting oxide; X-ray diffraction; ZnO; Introduction Transparent conductive oxides (TCOs), with both high electrical conductivity and optical transparency, could be used as a

• by LPCVD. These three samples are characterized and analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM), and cathode luminescence (CL) measurements. The grain structure, average grain size, and associated strains are shown to agree well with the

Synthesis and functionalization of NaGdF₄:Yb,Er@NaGdF₄ core–shell nanoparticles for possible application as multimodal contrast agents

• Dovile Baziulyte-Paulaviciene,
• Vitalijus Karabanovas,
• Marius Stasys,
• Greta Jarockyte,
• Vilius Poderys,
• Simas Sakirzanovas and
• Ricardas Rotomskis

Beilstein J. Nanotechnol. 2017, 8, 1815–1824, doi:10.3762/bjnano.8.183

• contrast probe for in vivo bioimaging. Keywords: cancer theranostics; core–shell structure; luminescence; multimodal; nanoparticles; upconverting nanoparticles; upconversion; Introduction Lanthanide-doped multimodal upconverting nanoparticles (UCNPs), which can convert near-infrared (NIR) radiation into

• . Hexagonal phase sodium gadolinium fluoride β-NaGdF4 is an ideal matrix for the creation optical/magnetic dual-modal bioprobes, but upconversion luminescence (UCL) efficiency of this host material is still low and needs to be improved. A major method to enhance the UCL intensity is to use a core–shell

• phase NaGdF4 (a host material exhibiting about an order of magnitude higher upconversion luminescence efficiency compared to cubic ones) with great optical and magnetic properties while maintaining a small size (<20 nm). The next problem is that those nanoparticles are often synthesized in an organic

Collembola cuticles and the three-phase line tension

• Håkon Gundersen,
• Hans Petter Leinaas and
• Christian Thaulow

Beilstein J. Nanotechnol. 2017, 8, 1714–1722, doi:10.3762/bjnano.8.172

• . Setae, rings in the cuticle around the base of setae, primary and secondary granules were imaged in fluorescent lighting on unstained samples (not all features were equally autofluorescent on all studied species). This autofluorescence effect can easily be distinguished by its weaker luminescence. On

Luminescent supramolecular hydrogels from a tripeptide and nitrogen-doped carbon nanodots

• Maria C. Cringoli,
• Slavko Kralj,
• Marina Kurbasic,
• Massimo Urban and
• Silvia Marchesan

Beilstein J. Nanotechnol. 2017, 8, 1553–1562, doi:10.3762/bjnano.8.157

• system could be valuable for the development of wound healing applications [28], whereby luminescence could be advantageous to visually track the presence of the hydrogel and the ability of its components to penetrate through the derma [29]. In addition, peptide hydrogels based on the Phe-Phe motif [30

• observations discussed above. Importantly, NCND addition not only provided luminescence to the hydrogels, but also allowed control over the well-known issue of heterogeneous thickness of supramolecular peptide fibers, resulting in improved viscoelastic properties of the final materials. Experimental All

Calcium fluoride based multifunctional nanoparticles for multimodal imaging

• Marion Straßer,
• Joachim H. X. Schrauth,
• Sofia Dembski,
• Daniel Haddad,
• Bernd Ahrens,
• Stefan Schweizer,
• Bastian Christ,
• Alevtina Cubukova,
• Marco Metzger,
• Heike Walles,
• Peter M. Jakob and
• Gerhard Sextl

Beilstein J. Nanotechnol. 2017, 8, 1484–1493, doi:10.3762/bjnano.8.148

• 100 μL of basal medium and 100 μL of CellTiter-Glo reagent and luminescence was measured after two minutes of shaking and ten minutes incubation at room temperature in a TECAN plate reader (infinite M200, TECAN, Maennedorf, Switzerland). According to DIN EN ISO 10993-5, a more than 20% deviation of

• green luminescence matches the maximum of the emission spectrum. a) T1-weighted MR image of the CaF2:(Tb3+,Gd3+) NPs with different concentrations in the range from 0.4 to 18.2 mg·mL−1 (1–10). I–III are reference samples of water and two concentrations of Magnevist. The different concentrations result

Spin-chemistry concepts for spintronics scientists

• Konstantin L. Ivanov,
• Alexander Wagenpfahl,
• Carsten Deibel and
• Jörg Matysik

Beilstein J. Nanotechnol. 2017, 8, 1427–1445, doi:10.3762/bjnano.8.143

• the sum of the radical radii. MFEs can be studied using different techniques. The concentration of radicals, as well as the radical pair recombination yield can be traced by detecting optical absorption, luminescence, photocurrent, etc. These quantities can be monitored either in steady-state

• RYDMR technique, which can be used for two purposes: (i) controlling the reactivity of radical pairs by using spin degrees of freedom and (ii) obtaining EPR parameters of short-lived radicals and radical pairs. RYDMR spectra can be obtained [95] by monitoring optical absorption, luminescence of the

AgCl-doped CdSe quantum dots with near-IR photoluminescence

• Pavel A. Kotin,
• Sergey S. Bubenov,
• Natalia E. Mordvinova and
• Sergey G. Dorofeev

Beilstein J. Nanotechnol. 2017, 8, 1156–1166, doi:10.3762/bjnano.8.117

• practical interest. In our case EPs play the major role in the formation of near-IR PL. To find the optimal conditions for obtaining near-IR luminescence we compare PL data of EPs from heavy fractions of samples AgCl_1 to AgCl_8 and of samples AgCl_10 to AgCl_40 (see Supporting Information File 1, Table S1

Nitrogen-doped twisted graphene grown on copper by atmospheric pressure CVD from a decane precursor

• Ivan V. Komissarov,
• Nikolai G. Kovalchuk,
• Vladimir A. Labunov,
• Ksenia V. Girel,
• Olga V. Korolik,
• Mikhail S. Tivanov,
• Algirdas Lazauskas,
• Mindaugas Andrulevičius,
• Tomas Tamulevičius,
• Viktoras Grigaliūnas,
• Šarunas Meškinis,
• Sigitas Tamulevičius and
• Serghej L. Prischepa

Beilstein J. Nanotechnol. 2017, 8, 145–158, doi:10.3762/bjnano.8.15

• ) sample A, (b) sample B on copper foil. The luminescence background from copper is subtracted. Insets: Measured 2D peak (symbols) with the Lorentz fit (line). (a) The Rayleigh image. (b) I2D/IG ratio map. (c) FWHM map of the 2D band. (d) 2D band position map. All data are for sample A on SiO2/Si substrate

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

• . The influence of the ratio of the precursors and the duration of the process on the properties of the O-dots was established and a mechanism of their formation was hypothesized. The multicolour luminescence tunability and toxicity of synthesized O-dots were extensively studied. The possible

• applications of O-dots for alive/fixed cell staining and labelling of layer-by-layer polyelectrolyte microcapsules were evaluated. Keywords: cell culture; citric acid; layer-by-layer (LbL)-microcapsules; luminescence; organic dots (O-dots); staining; toxicity; Introduction Luminescent nanosized semiconductor

• distinctive feature of type-II dots is that their emission wavelength depends on the excitation wavelength. In contrast, type-I O-dots obey Kasha's rule; the excitation wavelength affects the intensity of the luminescence only, but not the wavelength (colour) of the emitted light (see Supporting Information

Active and fast charge-state switching of single NV centres in diamond by in-plane Al-Schottky junctions

• Christoph Schreyvogel,
• Vladimir Polyakov,
• Sina Burk,
• Helmut Fedder,
• Andrej Denisenko,
• Felipe Fávaro de Oliveira,
• Ralf Wunderlich,
• Jan Meijer,
• Verena Zuerbig,
• Jörg Wrachtrup and
• Christoph E. Nebel

Beilstein J. Nanotechnol. 2016, 7, 1727–1735, doi:10.3762/bjnano.7.165

• show fluorescence upon optical excitation, whereas NV0 and NV− show a zero phonon line at 575 nm at 637 nm, respectively, with their corresponding phonon side bands [8]. A PL-intensity mapping performed on the surface shows bright spots originating from NV luminescence (Figure 1a). An analysing of PL

High performance Ce-doped ZnO nanorods for sunlight-driven photocatalysis

• Bilel Chouchene,
• Tahar Ben Chaabane,
• Lavinia Balan,
• Emilien Girot,
• Kevin Mozet,
• Ghouti Medjahdi and
• Raphaël Schneider

Beilstein J. Nanotechnol. 2016, 7, 1338–1349, doi:10.3762/bjnano.7.125

• significant attention, especially with cerium. Ce3+ possesses shielded 4f levels, which allow various well-defined narrow optical transitions between the spin-orbit levels and thus split the bandgap of ZnO into sub-gaps. For this reason, Ce3+ is generally doped or associated to ZnO to improve the luminescence