Band tail state related photoluminescence and photoresponse of ZnMgO solid solution nanostructured films

• Vadim Morari,
• Aida Pantazi,
• Nicolai Curmei,
• Vitalie Postolache,
• Emil V. Rusu,
• Marius Enachescu,
• Ion M. Tiginyanu and
• Veaceslav V. Ursaki

Beilstein J. Nanotechnol. 2020, 11, 899–910, doi:10.3762/bjnano.11.75

• emission properties were studied by photoluminescence spectroscopy under excitation at 325 nm. It was found that annealing at 500 °C leads to the production of macroscopically homogeneous wurtzite phase films, while thermal treatment at higher or lower temperature results in the degradation of the

• morphology, or in the formation of ZnO particles embedded into the ZnMgO matrix, respectively. Local compositional fluctuations leading to the formation of deep band tails in the gap were deduced from photoluminescence spectra. A model for the band tail distribution in the bandgap is proposed as a function

• ; photoluminescence; photosensitivity; spin coating; thin films; ZnMgO semiconductor alloy; Introduction The ZnMgO solid solution system is of interest due to the possibility to tailor many important physical properties by varying their composition. This alloy system covers a wide ultraviolet (UV) spectral range

Light–matter interactions in two-dimensional layered WSe₂ for gauging evolution of phonon dynamics

• Avra S. Bandyopadhyay,
• Chandan Biswas and
• Anupama B. Kaul

Beilstein J. Nanotechnol. 2020, 11, 782–797, doi:10.3762/bjnano.11.63

• of Electrical and Computer Engineering, University of Texas, El Paso, TX 79968, United States 10.3762/bjnano.11.63 Abstract Phonon dynamics is explored in mechanically exfoliated two-dimensional WSe2 using temperature-dependent and laser-power-dependent Raman and photoluminescence (PL) spectroscopy

• well-understood that the underlying factors governing the optical, electronic and thermal properties of solid-state materials are strongly influenced by phonons and their spatio-temporal response toward external stimuli. Raman and photoluminescence (PL) spectroscopy has been a remarkable tool to gauge

• change with temperature, which could also affect the phonon shifts in the and A1g modes, as found in Figure 3c. Phonon concentration from temperature-dependent PL analysis in WSe2 Photoluminescence spectroscopy was carried out similarly as the temperature was varied at fixed P = 3.35 mW for 1L, ML and

Hexagonal boron nitride: a review of the emerging material platform for single-photon sources and the spin–photon interface

• Stefania Castelletto,
• Faraz A. Inam,
• Shin-ichiro Sato and
• Alberto Boretti

Beilstein J. Nanotechnol. 2020, 11, 740–769, doi:10.3762/bjnano.11.61

• materials even if hyperfine interaction with nearby nuclear spins has been observed. To investigate materials in terms of tailoring their quantum point defects, the historical approach consists in presenting previous studies of photoluminescent point defects, their ensemble photoluminescence (PL

• (ideally on average 1 photon/pulse); and short lifetime and thus high repetition rate (>GHz), room temperature operation, high extraction efficiency (>90%). The SPS spectral purity can be measured with high-resolution photoluminescence (PL) excitation, (PLE). Photon indistinguishability is assessed when

Effect of Ag loading position on the photocatalytic performance of TiO₂ nanocolumn arrays

• Jinghan Xu,
• Yanqi Liu and
• Yan Zhao

Beilstein J. Nanotechnol. 2020, 11, 717–728, doi:10.3762/bjnano.11.59

• structures were observed using a field emission scanning electron microscope (FE-SEM, FEI, Tecnai G2 F30). The elemental composition and valence distribution of the film were measured by X-ray photoelectron spectroscopy (XPS, Thermo Fisher Scientific, ESCALAB 250Xi). The photoluminescence (PL) intensity of

Soybean-derived blue photoluminescent carbon dots

• Shanshan Wang,
• Wei Sun,
• Dong-sheng Yang and
• Fuqian Yang

Beilstein J. Nanotechnol. 2020, 11, 606–619, doi:10.3762/bjnano.11.48

• introduces nitrogen-containing surface-functional groups and leads to the recovery of the photoluminescent features that are different from those of the HTC-CDs and dependent on the fraction of nitrogen in the surface-functional groups. The photoluminescence of both the HTC-CDs and LA-CDs is largely due to

• to introduce N-surface-functional groups to carbon nanoparticles made from biomass and biowaste and to produce stable photoluminescent CDs with excellent water-wettability. Keywords: biomass; carbon dots; hydrothermal process; laser ablation; N-doping; photoluminescence; Introduction Carbon-based

• synthesized from glassy carbon [16], graphite [26], polymethyl methacrylate (PMMA) [27], and a graphite–cement mixture [6] via LAL in various liquids. In general, there are three major mechanisms contributing to the photoluminescence (PL) of CDs: 1) size-dependent bandgap (quantum confinement), 2) surface

Luminescent gold nanoclusters for bioimaging applications

• Nonappa

Beilstein J. Nanotechnol. 2020, 11, 533–546, doi:10.3762/bjnano.11.42

• emerged as attractive candidates for sensing, catalysis and bioimaging applications in recent years. For practical use in bioimaging, nanomaterials with high photoluminescence, quantum yield, photostability and large Stokes shifts are needed. While offering high photoluminescence and quantum yield

• [18][19]. Luminescent nanomaterials including semiconductor quantum dots, carbon dots, metal-doped nanoparticles, noble-metal nanoparticles, and organic–inorganic hybrid nanoparticles, have been studied for their ultrabright photoluminescence (PL) [20][21][22][23]. Semiconductor quantum dots (SCQDs

• quantum confinement, and the evolution of continuous or quasicontinuous bands (of bulk gold) into discrete electronic states [40]. Another attractive property of AuNCs is photoluminescence (PL), a phenomenon that is much less understood than the surface plasmon resonance of plasmonic gold nanoparticles

Interfacial charge transfer processes in 2D and 3D semiconducting hybrid perovskites: azobenzene as photoswitchable ligand

• Nicole Fillafer,
• Tobias Seewald,
• Lukas Schmidt-Mende and
• Sebastian Polarz

Beilstein J. Nanotechnol. 2020, 11, 466–479, doi:10.3762/bjnano.11.38

• of the materials. Sasai et al. were the first to observe a photoswitching reaction between the perovskite sheets using a combination of UV–vis irradiation and photoluminescence [41]. However, in particular the aspect of photoswitching of azobenzene–perovskite hybrids is still very unclear. For this

• synthesis of nanoscaled hybrid perovskite particles with insulating alkyl ligands usually a bright luminescent material is obtained (see the photography in Figure 6B) [48][49][50]. Although the relative energies of VB and CB are in good agreement with literature, the visible photoluminescence (PL) of the

• -resolved photoluminescence (PL) measurements of particles suspended in toluene were obtained using a FluoTime 300 from Picoquant spectrometer. Transient absorption spectra (TAS) were measured of drop-cast particles on glass substrates. NMR measurements of particles were carried out in a Bruker Avance III

Synthesis and enhanced photocatalytic performance of 0D/2D CuO/tourmaline composite photocatalysts

• Changqiang Yu,
• Min Wen,
• Zhen Tong,
• Shuhua Li,
• Yanhong Yin,
• Xianbin Liu,
• Yesheng Li,
• Tongxiang Liang,
• Ziping Wu and
• Dionysios D. Dionysiou

Beilstein J. Nanotechnol. 2020, 11, 407–416, doi:10.3762/bjnano.11.31

• ) spectra. UV–visible diffuse reflectance spectra were measured using a Lambda 750S UV–vis spectrophotometer (Perkin-Elmer, USA) calibrated using barium sulfate. Photoluminescence (PL) spectra were measured with a F-4600 fluorescence spectrophotometer (Hitachi, Japan) with an excitation wavelength of 400 nm

Recent progress in perovskite solar cells: the perovskite layer

• Xianfeng Dai,
• Ke Xu and
• Fanan Wei

Beilstein J. Nanotechnol. 2020, 11, 51–60, doi:10.3762/bjnano.11.5

• suitable boiling point, effectively accelerated the crystallization rate of the corresponding 2DRP perovskite. This yielded smooth, dense films with an efficiency of 12.15% and long charge-carrier lifetime, high photoluminescence intensity, low trap density and improved stability. However, the PCE of 2D

Influence of the epitaxial composition on N-face GaN KOH etch kinetics determined by ICP-OES

• Markus Tautz,
• Maren T. Kuchenbrod,
• Joachim Hertkorn,
• Robert Weinberger,
• Martin Welzel,
• Arno Pfitzner and
• David Díaz Díaz

Beilstein J. Nanotechnol. 2020, 11, 41–50, doi:10.3762/bjnano.11.4

• structure of a GaN layer stack grown by metal organic chemical vapour deposition (MOCVD) was varied in the unintentionally doped u-GaN bulk region. Different sequences of 2D and 3D grown layers led to a variation in dislocation density, which was monitored by photoluminescence microscopy (PLM) and X-ray

• and a 2D GaN layer with a combined thickness of 2000 nm. A, C and E contained a rudimentary MQW to allow for photoluminescence microscopy (PLM) analysis of dislocation density. Wafer processing After growth with Ga-polarity, the Ga-face of epilayers were bonded to silicon carriers with a non-ohmic

Deterministic placement of ultra-bright near-infrared color centers in arrays of silicon carbide micropillars

• Stefania Castelletto,
• Abdul Salam Al Atem,
• Faraz Ahmed Inam,
• Hans Jürgen von Bardeleben,
• Sophie Hameau,
• Ahmed Fahad Almutairi,
• Gérard Guillot,
• Shin-ichiro Sato,
• Alberto Boretti and
• Jean Marie Bluet

Beilstein J. Nanotechnol. 2019, 10, 2383–2395, doi:10.3762/bjnano.10.229

• emission of at least a factor of 6 using micro-photoluminescence systems. Using custom confocal microscopy setups, we characterized the emission of VSi measuring an enhancement by up to a factor of 20, and of NCVSi with an enhancement up to a factor of 7. The experimental results are supported by finite

• integrated photonics applications. Most of SiC point defects were found more than one decade ago with methods based on measuring ensemble photoluminescence (PL) [20], i.e., the light emission after the absorption of photons, and electron paramagnetic resonance (EPR) [21], which reveals unpaired electrons

• for the VSi and the nitrogen vacancy (NCVSi) [36]. Micropillars in other materials have been successfully used as photonics structures designed to improve the photoluminescence performance of quantum dots for strong coupling of the emission with the photonics cavity, high photon-extraction efficiency

Polyvinylpyrrolidone as additive for perovskite solar cells with water and isopropanol as solvents

• Chen Du,
• Shuo Wang,
• Xu Miao,
• Wenhai Sun,
• Yu Zhu,
• Chengyan Wang and
• Ruixin Ma

Beilstein J. Nanotechnol. 2019, 10, 2374–2382, doi:10.3762/bjnano.10.228

• monochromator. Infrared (IR) spectroscopy was performed using a Fourier transform IR spectrometer (VERTEX80v, Bruker). Photoluminescence (PL) spectra and the fluorescence decay curves were recorded with a computer controlled, modular spectro- fluorimeter (FLS980, Edinburgh). The active area of the cell was 0.1

• schematic reaction process of the deposition of perovskite films. (a) UV–vis measurement of the film without PVP additive and the film with PVP additive of 1 mg/mL. (b) The steady-state photoluminescence curves with an emission maximum at 760 nm were obtained upon excitation at 445 nm. (a) The current

Nitrogen-vacancy centers in diamond for nanoscale magnetic resonance imaging applications

• Alberto Boretti,
• Lorenzo Rosa,
• Jonathan Blackledge and
• Stefania Castelletto

Beilstein J. Nanotechnol. 2019, 10, 2128–2151, doi:10.3762/bjnano.10.207

• associated with NV center sensors for magnetic imaging applications. An NV center is an atomic size point defect in diamond. Standard optical techniques are capable of resolving the photoluminescence signal of a single NV center, the detection of which is facilitated particularly in the negative charge state

• (NV−). Room temperature manipulation of electron spins at the NV centers by means of magnetic or electric field, microwave or light irradiation, or a combination thereof, allows the generation of sharp resonances in the intensity and wavelength of the NV photoluminescence. The origin of these

• mounted on a thin platform, typically of less than 1 μm thickness. Coupled with the nanopillar, this diamond film makes a scanning probe when mounted to an AFM head. It is expected that this method can enhance the photoluminescence collected from the NV by a factor of 10. Finally, ND embedded in a living

Improved adsorption and degradation performance by S-doping of (001)-TiO₂

• Xiao-Yu Sun,
• Xian Zhang,
• Xiao Sun,
• Ni-Xian Qian,
• Min Wang and
• Yong-Qing Ma

Beilstein J. Nanotechnol. 2019, 10, 2116–2127, doi:10.3762/bjnano.10.206

• Instruments, USA). The pore size distribution was calculated using the Barret–Joyner–Halenda (BJH) method. The photoluminescence (PL) was measured on a fluorescence spectrophotometer (F-4500, Hitachi, Japan). Electron spin resonance (ESR) signals of the reactive species spin trapped by 5,5-dimethyl-1

Review of advanced sensor devices employing nanoarchitectonics concepts

• Katsuhiko Ariga,
• Tatsuyuki Makita,
• Masato Ito,
• Taizo Mori,
• Shun Watanabe and
• Jun Takeya

Beilstein J. Nanotechnol. 2019, 10, 2014–2030, doi:10.3762/bjnano.10.198

• photoluminescence. The sensing films consisting of paper and ZnO could realize a very sensitive water detection with a relative humidity of less than 1% and the detection of trace-level water of less than 0.05%. In addition, the interference from any small molecules other than water is also avoided. The precise

Optimization and performance of nitrogen-doped carbon dots as a color conversion layer for white-LED applications

• Tugrul Guner,
• Hurriyet Yuce,
• Didem Tascioglu,
• Eren Simsek,
• Umut Savaci,
• Aziz Genc,
• Servet Turan and
• Mustafa M. Demir

Beilstein J. Nanotechnol. 2019, 10, 2004–2013, doi:10.3762/bjnano.10.197

• -Alpha XPS spectrometer. Fourier-transform infrared spectroscopy (FTIR; Spectrum 100, PerkinElmer, Shelton, CT, USA) was used to characterize the kinetic behavior of the chemical bonds. Photoluminescence (PL) and absorbance were measured using an integrating sphere (ISP-50-80-R, Ocean Optics Inc

Materials nanoarchitectonics at two-dimensional liquid interfaces

• Katsuhiko Ariga,
• Michio Matsumoto,
• Taizo Mori and
• Lok Kumar Shrestha

Beilstein J. Nanotechnol. 2019, 10, 1559–1587, doi:10.3762/bjnano.10.153

• as an alternative to commercial photodetector devices with CdS and CdSe. Enhanced photoluminescence and photoelectrochemical properties of one-dimensional Lu2@C82 nanorods prepared through liquid–liquid interfacial precipitation between carbon disulfide and 2-propanol were demonstrated by Lu and co

• -workers [249]. Photoluminescence of the one-dimensional Lu2@C82 nanorods was remarkably enhanced compared to the pristine Lu2@C82 powder. The increased charge carrier transport would be also useful for applications with photoelectric purposes such as photodetectors. 4.3 Two- and three-dimensional, and

BiOCl/TiO₂/diatomite composites with enhanced visible-light photocatalytic activity for the degradation of rhodamine B

• Minlin Ao,
• Kun Liu,
• Xuekun Tang,
• Zishun Li,
• Qian Peng and
• Jing Huang

Beilstein J. Nanotechnol. 2019, 10, 1412–1422, doi:10.3762/bjnano.10.139

• CHI700E) with blue light (400–450 nm) irradiation. The steady-state photoluminescence (PL) spectra of the samples were detected by using a Hitachi F-7000 fluorescence spectrophotometer with excitation at 280 nm. Photocatalytic activity tests With visible-light irradiation, the photocatalytic activity was

• efficiency of the samples, photoluminescence spectroscopy, photocurrent and electrochemical impedance spectroscopy were tested. The recombination rate of photogenerated carriers (electrons and holes) in photocatalysts was characterized by photoluminescence spectra. Generally, the lower the spectral intensity

• ), and BTD prepared with different calcination temperatures (c and f). UV–vis absorption spectra (a) and band gap energy (b) of various samples. Mott–Schottky plots of BiOCl (a) and TiO2/diatomite (b). Photoluminescence spectra (a), transient photocurrent spectra (b) and electrochemical impedance spectra

Janus-micromotor-based on–off luminescence sensor for active TNT detection

• Ye Yuan,
• Changyong Gao,
• Daolin Wang,
• Chang Zhou,
• Baohua Zhu and
• Qiang He

Beilstein J. Nanotechnol. 2019, 10, 1324–1331, doi:10.3762/bjnano.10.131

• affect the photoluminescence properties of the UCNPs (Figure 1e). Furthermore, the structure and morphology of the Janus UCNP capsule motors were systematically characterized. The TEM images in Figure 1f show a microcapsule after functionalizing with UCNPs. It is evident that the APTES-UCNPs were

Green fabrication of lanthanide-doped hydroxide-based phosphors: Y(OH)₃:Eu³⁺ nanoparticles for white light generation

• Tugrul Guner,
• Anilcan Kus,
• Mehmet Ozcan,
• Aziz Genc,
• Hasan Sahin and
• Mustafa M. Demir

Beilstein J. Nanotechnol. 2019, 10, 1200–1210, doi:10.3762/bjnano.10.119

• 5p orbitals [25]. Moreover, the photoluminescence (PL) intensity depends on the transition between 4f → 4f states; the transition from 5D0 to 7F1, 5D0 to 7F3 and 5D0 to 7F4 results in low intensity, while the transition from 5D0 to 7F2 leads to high PL intensity. Therefore, by manipulating the energy

• building blocks of these agglomerates seem to have sizes smaller than 5 nm. The photoluminescence spectrum of the Y(OH)3:7.5% Eu3+ phosphors that were synthesized at varying times was registered at 365 nm excitation wavelength (Figure 1d). At the first 5 min, sharp emission signals appear at 592, 595, 613

• slightly Eu-rich or Y-rich regions. The effect of the doping ratio on the photoluminescence properties was investigated. Figure 4a presents the PL spectra of the Y(OH)3:Eu3+ red phosphors fabricated at 60 min having various dopant ratios (λExc = 365 nm). Characteristic signals of the corresponding

Photoactive nanoarchitectures based on clays incorporating TiO₂ and ZnO nanoparticles

• Eduardo Ruiz-Hitzky,
• Pilar Aranda,
• Marwa Akkari,
• Nithima Khaorapapong and
• Makoto Ogawa

Beilstein J. Nanotechnol. 2019, 10, 1140–1156, doi:10.3762/bjnano.10.114

• using smectites such as natural montmorillonite, synthetic saponite, as well as the corresponding CTA-smectites, Khaorapapong and co-workers [46][92][93] synthesized diverse photocatalysts where the ZnO NPs were formed on the inner and/or outer surfaces of the CTA-smectites. The photoluminescence at

• visible wavelengths (blue and green emission at around 436–438 nm and 544–548 nm) of ZnO hybridized with CTA-smectites varies depending on the ZnO loading. This was attributed to defects, such as oxygen vacancies in ZnO, and trapped surface charges. The photoluminescence intensity of ZnO in saponite and

• metal oxides exhibit a large exciton binding energy, large piezoelectric constants and strong photoluminescence. This is of interest not only for applications as photocatalysts but also as sensors, solar cell devices, disinfectants, and cosmetics [137][138]. As discussed above, the dispersion of the

CuInSe₂ quantum dots grown by molecular beam epitaxy on amorphous SiO₂ surfaces

• Henrique Limborço,
• Pedro M.P. Salomé,
• Rodrigo Ribeiro-Andrade,
• Jennifer P. Teixeira,
• Nicoleta Nicoara,
• Kamal Abderrafi,
• Joaquim P. Leitão,
• Juan C. Gonzalez and
• Sascha Sadewasser

Beilstein J. Nanotechnol. 2019, 10, 1103–1111, doi:10.3762/bjnano.10.110

• confirmed the crystallinity of the nanodots as well as chemical composition and structure compatible with tetragonal CuInSe2. Photoluminescence measurements of CdS-passivated nanodots showed that the nanodots are optoelectronically active with a broad emission extending to energies above the CuInSe2 bulk

• bandgap and in agreement with the distribution of sizes. A blue-shift of the luminescence is observed as the average size of the nanodots gets smaller, evidencing quantum confinement in all samples. By using simple quantum confinement calculations, we correlate the photoluminescence peak emission energy

• materials [31]. The motivation behind the present work is to grow CIS nanodots on substrates covered with an amorphous layer using co-evaporation. The vacuum conditions of the co-evaporation process will allow for the CIS to keep adequate optoelectronic properties, as demonstrated by the photoluminescence

Structural and optical properties of penicillamine-protected gold nanocluster fractions separated by sequential size-selective fractionation

• Xiupei Yang,
• Zhengli Yang,
• Fenglin Tang,
• Jing Xu,
• Maoxue Zhang and
• Martin M. F. Choi

Beilstein J. Nanotechnol. 2019, 10, 955–966, doi:10.3762/bjnano.10.96

• size and the ratio of Au atoms to ligands of AuNCs. X-ray photoelectron spectroscopy (XPS) has also been applied to observe the molecular dependence on the gold and sulfur chemical state of organosulfur monolayers of the fractions. The photoluminescence spectra of these AuNCs in the range of 900–790 nm

• fractionation, the crude AuNCs and fractions obtained from SSSP have been investigated by transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), nuclear magnetic resonance (NMR), and UV–vis absorption together with photoluminescence (PL) spectroscopy. Experimental Chemicals and

• absorption and photoluminescence properties UV–vis absorption spectra of the AuNC crude product and the fractions are displayed in Figure 9. In order to eliminate the effect of concentration changes on the comparison of spectral shape and band position, these spectra are normalized at 250 nm. The smaller

Synthesis of novel C-doped g-C₃N₄ nanosheets coupled with CdIn₂S₄ for enhanced photocatalytic hydrogen evolution

• Jingshuai Chen,
• Chang-Jie Mao,
• Helin Niu and
• Ji-Ming Song

Beilstein J. Nanotechnol. 2019, 10, 912–921, doi:10.3762/bjnano.10.92

• -induced charge carriers of these as-fabricated samples has been studied via room temperature photoluminescence (PL) characterization. Figure 7 displays the PL emission spectra of g-C3N4, CCN and CISCCN3 hybrid photocatalysts at the excitation wavelength of 410 nm. It is observed that the pure CCN shows

• 1s, (c) N 1s, (d) Cd 3d, (e) In 3d and (f) S 2p. (a) UV–vis spectra of g-C3N4, CCN, CdIn2S4, and CISCCN composites. (b) The plot of (αhν)2 vs photon energy (hν) for g-C3N4, CCN and CdIn2S4. Photoluminescence spectra of g-C3N4, CCN and CISCCN3 samples. (a) Time-dependent visible-light-induced

Towards rare-earth-free white light-emitting diode devices based on the combination of dicyanomethylene and pyranine as organic dyes supported on zinc single-layered hydroxide

• Jeff L. Nyalosaso,
• Rachod Boonsin,
• Pierre Vialat,
• Damien Boyer,
• Geneviève Chadeyron,
• Rachid Mahiou and
• Fabrice Leroux

Beilstein J. Nanotechnol. 2019, 10, 760–770, doi:10.3762/bjnano.10.75

• occur. Photoluminescence properties of the integrated dyes Absolute quantum yield (QYab) is defined as the efficiency at which a given material re-emits by fluorescence a certain number of photons absorbed at a given wavelength. The parameters measured in a 3.3 inch integrating sphere provide

• the photoluminescence performance of the studied material. A fraction of the excitation light will be absorbed by the dye molecule, internally converted, transferred and emitted at a longer wavelength. Figure 4 illustrates the recording of the evolution of photoluminescence QYab as a function of

• interpretation of QYab insofar as a part of dye that is in solution (free dyes existing in the wet compound) would dictate its photoluminescence properties (leading to higher QYab values), therefore masking those intrinsic to the solid (dyes actually supported on Zn-SLH). The measurements of QYab on the films