Variation of the photoluminescence spectrum of InAs/GaAs heterostructures grown by ion-beam deposition

• Alexander S. Pashchenko,
• Leonid S. Lunin,
• Eleonora M. Danilina and
• Sergei N. Chebotarev

Beilstein J. Nanotechnol. 2018, 9, 2794–2801, doi:10.3762/bjnano.9.261

• their isovalent doping with bismuth on the photoluminescence properties of InAs/GaAs heterostructures. The experimental samples were grown by ion-beam deposition. We showed that using three vertically stacked layers of InAs quantum dots separated by thin GaAs barrier layers was accompanied by a red

• -shift of the photoluminescence peak of InAs/GaAs heterostructures. An increase in the thickness of the GaAs barrier layers was accompanied by a blue shift of the photoluminescence peak. The effect of isovalent Bi doping of the GaAs barrier layers on the structural and optical properties of the InAs/GaAs

• . It is shown that isovalent doping of GaAs potential barriers by bismuth was accompanied by a red-shift of the photoluminescence peak of InAs quantum dots of 121 meV. Keywords: infrared photodetectors; ion-beam deposition; nanoheterostructures; photoluminescence; quantum dot; semiconductors

Near-infrared light harvesting of upconverting NaYF₄:Yb³⁺/Er³⁺-based amorphous silicon solar cells investigated by an optical filter

• Daiming Liu,
• Qingkang Wang and
• Qing Wang

Beilstein J. Nanotechnol. 2018, 9, 2788–2793, doi:10.3762/bjnano.9.260

• XRD results revealed the morphology and a phase transition from cubic to hexagonal NaYF4. Photoluminescence spectra indicated that the hexagonal NaYF4:Yb3+/Er3+ nanorods convert near-infrared light of 980 nm to the visible light with wavelength peaks at 654, 541 and 522 nm. Hence, the upconverting

• efficient UC materials [15][16]. Photoluminescence spectra of NaYF4:Yb3+/Er3+ powders from 500 to 700 nm are presented in Figure 2a. Three strong emission peaks at 522, 541, and 654 nm are observed. The intensity of each emission peak increases with increasing reaction time (Figure 2b), which is interpreted

• as an increase in the fraction of the hexagonal phase. The quantum efficiency of the hexagonal nanorods is about an order of magnitude higher than that of the cubic phase counterparts [17]. The photoluminescence of NaYF4:Yb3+/Er3+ is explained by energy transfer between Yb3+ and Er3+. As illustrated

Oriented zinc oxide nanorods: A novel saturable absorber for lasers in the near-infrared

• Pavel Loiko,
• Tanujjal Bora,
• Josep Maria Serres,
• Haohai Yu,
• Magdalena Aguiló,
• Francesc Díaz,
• Uwe Griebner,
• Valentin Petrov,
• Xavier Mateos and
• Joydeep Dutta

Beilstein J. Nanotechnol. 2018, 9, 2730–2740, doi:10.3762/bjnano.9.255

• exciton binding energy (60 meV) [3], allowing for efficient excitonic photoluminescence at room temperature, and due to their good mechanical and thermal stability. Arrays of ZnO NRs can be grown on various substrates (e.g., Si, Al2O3, glass) either by gas phase processes (e.g., by vapor–liquid–solid

• commercial graphene-SA containing several (n = 3) carbon layers, a SA based on randomly oriented SWCNTs in a PMMA film [32], and a few-layer MoS2 SA [31]. One can observe a similar broadband absorption feature for the ZnO NRs as in these reference SAs. The photoluminescence (PL) spectrum of ZnO NRs grown for

• with n = 3 carbon layers, multilayer MoS2 film [31] and SWCNT/PMMA film [32]; (d) room temperature photoluminescence (PL) spectrum of ZnO NRs grown for 15 h, the excitation wavelength is 0.350 µm: grey curve – the measured PL spectrum, color bands – decomposition of the PL spectrum into Gaussian

Low cost tips for tip-enhanced Raman spectroscopy fabricated by two-step electrochemical etching of 125 µm diameter gold wires

• Antonino Foti,
• Francesco Barreca,
• Enza Fazio,
• Cristiano D’Andrea,
• Paolo Matteini,
• Onofrio Maria Maragò and
• Pietro Giuseppe Gucciardi

Beilstein J. Nanotechnol. 2018, 9, 2718–2729, doi:10.3762/bjnano.9.254

• nanocube monomers [53] predict a 100-fold smaller light emission with respect to the nanocube-on-surface configuration, and the origin of the signal is attributed to photoluminescence rather than to ERS. Sanders et al. [57], working on Au-coated spherical AFM tips, have shown a remarkable correlation

Silencing the second harmonic generation from plasmonic nanodimers: A comprehensive discussion

• Jérémy Butet,
• Gabriel D. Bernasconi and
• Olivier J. F. Martin

Beilstein J. Nanotechnol. 2018, 9, 2674–2683, doi:10.3762/bjnano.9.250

• optical processes, such as multiphoton photoluminescence [6], third harmonic generation [14][15], and four-wave mixing [16][17]. However, the enhancement of the nonlinear conversion rate for second harmonic generation (SHG) was found to be surprisingly low [18][19]. This is in contrast with the

• been addressed in the case of connected gold nanodimers by comparing the evolution of the SHG with that of the two-photon photoluminescence [21]. It was shown that, although these two nonlinear optical processes involved two fundamental photons, they did not have the same incident polarization

Polarization-dependent strong coupling between silver nanorods and photochromic molecules

• Gwénaëlle Lamri,
• Alessandro Veltri,
• Jean Aubard,
• Pierre-Michel Adam,
• Nordin Felidj and
• Anne-Laure Baudrion

Beilstein J. Nanotechnol. 2018, 9, 2657–2664, doi:10.3762/bjnano.9.247

• on and off, resulting in the controlled enhancement of the photoluminescence produced by the emitter. (a) SEM image of silver nanorods. The 0° and 90° polarization orientations correspond to the nanorod long and short axes, respectively. (b) Extinction spectra of silver nanorods in air. The width is

Au–Si plasmonic platforms: synthesis, structure and FDTD simulations

• Anna Gapska,
• Marcin Łapiński,
• Paweł Syty,
• Wojciech Sadowski,
• Józef E. Sienkiewicz and
• Barbara Kościelska

Beilstein J. Nanotechnol. 2018, 9, 2599–2608, doi:10.3762/bjnano.9.241

• . Of course, this increase was closely related to the development of novel manufacturing technologies. One of the most interesting fields based on metal nanostructures is plasmonics. The use of plasmonic effects opens up many interesting possibilities, as for example photoluminescence intensification

Metal–dielectric hybrid nanoantennas for efficient frequency conversion at the anapole mode

• Valerio F. Gili,
• Lavinia Ghirardini,
• Davide Rocco,
• Giuseppe Marino,
• Ivan Favero,
• Iännis Roland,
• Giovanni Pellegrini,
• Lamberto Duò,
• Marco Finazzi,
• Luca Carletti,
• Andrea Locatelli,
• Aristide Lemaître,
• Dragomir Neshev,
• Costantino De Angelis,
• Giuseppe Leo and
• Michele Celebrano

Beilstein J. Nanotechnol. 2018, 9, 2306–2314, doi:10.3762/bjnano.9.215

• polarization direction with a half-wavelength plate. The nonlinear emission from the antennas is collected in reflection geometry and filtered before detection with a short-pass filter at 1000 nm and with a narrow-band filter at 775 nm to eliminate the residual pump signal and any TH and photoluminescence

Hierarchical heterostructures of Bi₂MoO₆ microflowers decorated with Ag₂CO₃ nanoparticles for efficient visible-light-driven photocatalytic removal of toxic pollutants

• Shijie Li,
• Wei Jiang,
• Shiwei Hu,
• Yu Liu,
• Yanping Liu,
• Kaibing Xu and
• Jianshe Liu

Beilstein J. Nanotechnol. 2018, 9, 2297–2305, doi:10.3762/bjnano.9.214

• D8 Advance) with a scanning range of 2θ from 20° to 80°. The UV–vis spectra were recorded using an UV-2600 UV–vis spectrophotometer (Shimadzu). The photoluminescence (PL) emission spectra of the samples were recorded on a Hitachi F-7000 spectrophotometer, employing an excitation wavelength of 300 nm

Two-dimensional photonic crystals increasing vertical light emission from Si nanocrystal-rich thin layers

• Lukáš Ondič,
• Marian Varga,
• Ivan Pelant,
• Alexander Kromka,
• Karel Hruška and
• Robert G. Elliman

Beilstein J. Nanotechnol. 2018, 9, 2287–2296, doi:10.3762/bjnano.9.213

• , Australia 10.3762/bjnano.9.213 Abstract We have fabricated two-dimensional photonic crystals (PhCs) on the surface of Si nanocrystal-rich SiO2 layers with the goal to maximize the photoluminescence extraction efficiency in the normal direction. The fabricated periodic structures consist of columns ordered

• into square and hexagonal pattern with lattice constants computed such that the red photoluminescence of Si nanocrystals (SiNCs) could couple to leaky modes of the PhCs and could be efficiently extracted to surrounding air. Samples having different lattice constants and heights of columns were

• reflectance spectra. The extraction enhancement within different spatial angles was evaluated by means of micro-photoluminescence spectroscopy. More than 18-fold extraction enhancement was achieved for light propagating in the normal direction and up to 22% increase in overall intensity was obtained at the

Lead-free hybrid perovskites for photovoltaics

• Oleksandr Stroyuk

Beilstein J. Nanotechnol. 2018, 9, 2209–2235, doi:10.3762/bjnano.9.207

• structure up to 90% Mn [99]. Up to 46% Pb2+ ions can be exchanged with Mn2+ in CsPbCl3 NCs produced by hot-injection, resulting in a highly increased photoluminescence (PL) efficiency [100]. Mixed MAPbxMn1−xI1+2xCl2−2x (x = 0.1–1.0) synthesized by a solid-state reaction displayed an unprecedentedly high

Electrospun one-dimensional nanostructures: a new horizon for gas sensing materials

• Muhammad Imran,
• Nunzio Motta and
• Mahnaz Shafiei

Beilstein J. Nanotechnol. 2018, 9, 2128–2170, doi:10.3762/bjnano.9.202

Multimodal noncontact atomic force microscopy and Kelvin probe force microscopy investigations of organolead tribromide perovskite single crystals

• Yann Almadori,
• David Moerman,
• Jaume Llacer Martinez,
• Philippe Leclère and
• Benjamin Grévin

Beilstein J. Nanotechnol. 2018, 9, 1695–1704, doi:10.3762/bjnano.9.161

• , including a direct band gap, high absorption coefficient, large and balanced carrier mobility, high diffusion length, long carrier lifetime and high photoluminescence quantum yield. Within a few years of their discovery, these materials were successfully used to develop photovoltaic cells [2] with power

Sheet-on-belt branched TiO₂(B)/rGO powders with enhanced photocatalytic activity

• Huan Xing,
• Wei Wen and
• Jin-Ming Wu

Beilstein J. Nanotechnol. 2018, 9, 1550–1557, doi:10.3762/bjnano.9.146

• )/rGO powders. Figure 8 shows photoluminescence (PL) spectra of TGN and TGN-branch 4 h samples. The PL intensity of TGN is stronger than that of TGN-branch 4 h, indicating a faster recombination of carriers in TGN. This result demonstrates that growing branches on TGN contributes to the separation of

• photocatalytic activity [40]. Conclusion TiO2(B) nanosheet branches were uniformly in situ grown on TiO2/rGO nanobelt surfaces to form a unique sheet-on-belt nanostructure. Both trunks and branches were TiO2(B); however, the photoluminescence measurements suggest an enhanced charge separation of the branched

• was adopted to determine the specific surface area. The sample was degassed at 150 °C for 20 h to remove physisorbed gases prior to the measurement. The ambient photoluminescence (PL) emission spectra characterizations were carried out on a fluorescence spectrophotometer (HITACHI F-4500) with an

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

• , Russia 10.3762/bjnano.9.145 Abstract We have experimentally investigated the effect of the reorientation of a nematic liquid crystal (LC) in an electric field on the photoluminescence (PL) of CdSe/ZnS semiconductor quantum dots (QDs). To the LC with positive dielectric anisotropy, 1 wt % QDs with a core

• fields. The control of the QD luminescence in an LC matrix has both scientific and practical interest. The photoluminescence (PL) of liquid crystals doped with silver NPs, carbon nanotubes and quantum semiconductor nanoparticles were discussed in [11][12]. The control of PL of a nematic liquid crystal

• change their orientation. We have studied intensity and a decay time of QD photoluminescence as well as the change of particle size and distribution of QDs and ion current in the LC matrix. Experimental We used hydrophobic CdSe/ZnS quantum dots with a core diameter of 5 nm obtained from Belarusian State

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

• , which allows for completely N-free silicon oxide. In this work, we investigate the properties of B- and P-incorporating Si NCs embedded in pure silicon oxide compared to silicon oxynitride by atom probe tomography (APT), low-temperature photoluminescence (PL), transient transmission (TT), and current

• of P- or B-atoms has severe implications for future applications of conventional impurity doping of Si in sub-10 nm technology nodes. Keywords: atom probe tomography; doping; photoluminescence; silicon nanocrystals; transient transmission; Introduction The conductivity type and free carrier

• meaningful APT-analysis cannot be achieved. However, the absence of any significant differences between SRON:P and SRO:P suggests that the nitrogen in the oxynitride matrix will not have a notable influence on the B-distribution when SRON:B and SRO:B are compared. Photoluminescence and transient transmission

Cr(VI) remediation from aqueous environment through modified-TiO₂-mediated photocatalytic reduction

• Rashmi Acharya,
• Brundabana Naik and
• Kulamani Parida

Beilstein J. Nanotechnol. 2018, 9, 1448–1470, doi:10.3762/bjnano.9.137

• studies. Optical studies such as ultraviolet–visible diffuse reflectance spectroscopy (UV–vis DRS) and photoluminescence spectroscopy (PL) explain the shift of the absorption range to the visible region and prohibition of recombination of charge carriers, respectively. The doping of nonmetals such as N, S

• as co-catalysts because of their intriguing properties such as small size, high dispersion, abundant surface functional groups, unique photoluminescence and good electron transfer ability [141][142]. Carbon dot–TiO2 (CD–TiO2) nanosheet composites synthesized by a hydrothermal route were studied for

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

• ]. The defects are responsible for visible photoluminescence (PL) in TiO2 and have been observed in thin films [39][40][41], nanocrystals/nanoparticles [42][43][44][45][46][47], nanorods [48], nanotubes [49][50][51], nanosheets [52], nanoribbons [53] and fibres [54]. In material sciences, the PL spectrum

• surface defect sites [59] and surface oxygen vacancies on anatase nanocrystal films [60]. Similar photoluminescence in the red was also observed from ZnO defects [7][8][9]. The photodynamics of D1 was also recorded and can be seen for a pump power of 82 μW in Figure 4b. The time trace shows photostability

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

• probe microscopy, optical spectroscopy (photoluminescence and Raman) and ab initio calculations. The graphene/RA interaction induces the formation of a well-organized π-conjugated self-assembled monolayer (SAM) at the interface. Such structural organization leads to the high optical emission efficiency

• influences: graphene-promoted high photoluminescence efficiency of RA and RA-induced doping and charge modulation of graphene. The results suggest that low-dimensional hybrid systems, with reciprocal modifications of the constituents’ original properties, may tailor the desired properties in future device

• properties of this novel RA SAM structure. Therefore, photoluminescence (PL) studies of RA monolayers and multilayers atop graphite microplates were performed as a function of temperature (Figure 3). Initially, in order to emulate thick and disordered RA films, a graphite microplate substrate was spread

Facile synthesis of a ZnO–BiOI p–n nano-heterojunction with excellent visible-light photocatalytic activity

• Mengyuan Zhang,
• Jiaqian Qin,
• Pengfei Yu,
• Bing Zhang,
• Mingzhen Ma,
• Xinyu Zhang and
• Riping Liu

Beilstein J. Nanotechnol. 2018, 9, 789–800, doi:10.3762/bjnano.9.72

• carrier separation efficiency, photoluminescence (PL) emission spectra was carried out and the results are displayed in Figure S4, Supporting Information File 1. Generally speaking, stronger PL intensity indicates a higher photoinduced hole–electron recombination rate, which is not in the photocatalysts

Valley-selective directional emission from a transition-metal dichalcogenide monolayer mediated by a plasmonic nanoantenna

• Haitao Chen,
• Mingkai Liu,
• Lei Xu and
• Dragomir N. Neshev

Beilstein J. Nanotechnol. 2018, 9, 780–788, doi:10.3762/bjnano.9.71

• [6][7][8][9][10]. In particular, monolayer TMDCs with direct bandgap at the K and K′ points [11] make it possible to control the valley degree freedom entirely optically. Optical pumping of excitons of a specific valley polarization has been demonstrated by polarization-resolved photoluminescence (PL

Surface-plasmon-enhanced ultraviolet emission of Au-decorated ZnO structures for gas sensing and photocatalytic devices

• T. Anh Thu Do,
• Truong Giang Ho,
• Thu Hoai Bui,
• Quang Ngan Pham,
• Hong Thai Giang,
• Thi Thu Do,
• Duc Van Nguyen and
• Dai Lam Tran

Beilstein J. Nanotechnol. 2018, 9, 771–779, doi:10.3762/bjnano.9.70

• simple chemical bath deposition and photoreduction methods. The analysis of scanning electron microscopy (SEM) and transmission electron microscopy (TEM) images, energy-dispersive X-ray spectroscopy (EDS), UV–vis absorption, and photoluminescence (PL) spectra results were used to verify the incorporation

• of plasmonic Au nanoparticles (NPs) on the ZnO film. Time-resolved photoluminescence (TRPL) spectra indicated that a surface plasmonic effect exists with a fast rate of charge transfer from Au nanoparticles to the sub-micrometer ZnO sphere, which suggested the strong possibility of the use of the

• revealed that ZnO sub-micrometer spheres were deposited on the glass substrates and Au-decorated ZnO nanostructures were confirmed. Using photoluminescence (PL) spectra and time-resolved photoluminescence (TRPL) measurements, we investigate the SPR characteristics and ZnO exciton peaks, which complement

Perovskite-structured CaTiO₃ coupled with g-C₃N₄ as a heterojunction photocatalyst for organic pollutant degradation

• Ashish Kumar,
• Christian Schuerings,
• Suneel Kumar,
• Ajay Kumar and
• Venkata Krishnan

Beilstein J. Nanotechnol. 2018, 9, 671–685, doi:10.3762/bjnano.9.62

• disk was measured by diffuse reflectance spectroscopy (DRS). DRS studies were performed on a Perkin Elmer UV–visible–NIR Lambda 750 spectrophotometer by utilizing polytetrafluoroethylene (PTFE) polymer as a diffuse reflectance standard in the wavelength range 200–800 nm. Photoluminescence (PL

• the UV and visible light regions. In addition, photoluminescence (PL) spectroscopy studies were carried out in order to study the separation and migration of photogenerated charge carriers in the CTCN heterojunction. It is well-reported in literature that recombination of electrons and holes give rise

• heterojunction. Photoluminescence spectra of g-C3N4, CT and CTCN heterojunction. Nitrogen adsorption–desorption curves for (a) g-C3N4 (b) CT and (c) CTCN heterojunction; BET surface area plots for (d) g-C3N4 (e) CT and (f) CTCN heterojunction. Time-dependent absorption spectra of RhB degradation with the CTCN

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

• graphene quantum dots (GQDs) are emerging as new alternatives due to their excellent properties, including high photoluminescence, low photobleaching, high biocompatibility and low toxicity. C-dots avoid the use of heavy metals present in semiconductor quantum dots, which have raised important health and

• . Results and Discussion Absorption and photoluminescence characterization of C-dots The C-dots were synthesized using spices as starting material through a green one-pot hydrothermal method that involves pyrolysis, carbonization and passivation [33][34][35], with no need to add surface passivation agents

• 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

• that for photocatalysts obtained by the SHT method the agglomerates are a bit smaller. Optical and photoluminescence properties To study the optical absorption properties of the as-prepared photocatalysts, diffuse reflectance spectra (DRS) in the range of 200–850 nm were investigated, and the results

• states of 4G7/2 and 2K13/2, 4G5/2 and 2G7/2, 4S3/2 and 4F7/2, 4F5/2 and 2H9/2 [30][37]. In all of the studied Nd-modified samples, the intensity of these absorption bands was similar. To understand the rate of electron–hole recombination, photoluminescence (PL) spectroscopy was applied. Figure 4 shows

• the PL spectra of pristine and Nd-modified TiO2 under excitation by light at λex = 315 nm. The photoluminescence spectra show a weak broad emission band with a maximum intensity at around 350–700 nm. Khalid et al. [38] and Raja et al. [39] reported that emission in that range is characteristic for