Light extraction efficiency enhancement of flip-chip blue light-emitting diodes by anodic aluminum oxide

• Yi-Ru Huang,
• Yao-Ching Chiu,
• Kuan-Chieh Huang,
• Shao-Ying Ting,
• Po-Jui Chiang,
• Chih-Ming Lai,
• Chun-Ping Jen,
• Snow H. Tseng and
• Hsiang-Chen Wang

Beilstein J. Nanotechnol. 2018, 9, 1602–1612, doi:10.3762/bjnano.9.152

• on the fast Fourier transform of the green section in Figure 3d. The figure shows that the lattice structure is as regular as the hexagon lattice structure of Al. Figure 3e shows a magnified view of the red rectangle region shown in Figure 3c. This figure indicates that some pores have not been

Evaluation of replicas manufactured in a 3D-printed nanoimprint unit

• Manuel Caño-García,
• Morten A. Geday,
• Manuel Gil-Valverde,
• Xabier Quintana and
• José M. Otón

Beilstein J. Nanotechnol. 2018, 9, 1573–1581, doi:10.3762/bjnano.9.149

• account the 2D nature of the topography, 2D fast Fourier transform was applied on to obtain the spatial frequency. The pitch value is obtained from the inverse distance between the zeroth order and the first order of the FFT (actually the script takes the distance between the two first orders and divides

Optical near-field mapping of plasmonic nanostructures prepared by nanosphere lithography

• Gitanjali Kolhatkar,
• Alexandre Merlen,
• Jiawei Zhang,
• Chahinez Dab,
• Gregory Q. Wallace,
• François Lagugné-Labarthet and
• Andreas Ruediger

Beilstein J. Nanotechnol. 2018, 9, 1536–1543, doi:10.3762/bjnano.9.144

• periodicity of ≈3 µm−1 in the Fourier (2D reciprocal) space. The anisotropy of this pattern is also reflected in the 2D fast Fourier transform (FFT) of the optical image, presented in Figure 1c. In addition, those patterns vary with the polarization, and with the laser focus. Thus, these oscillation patterns

Artifacts in time-resolved Kelvin probe force microscopy

• Sascha Sadewasser,
• Nicoleta Nicoara and
• Santiago D. Solares

Beilstein J. Nanotechnol. 2018, 9, 1272–1281, doi:10.3762/bjnano.9.119

• pulses, the resulting time-dependent electrostatic forces are very complex and result in intricate mixing of frequencies that may, in some cases, have a component at the detection frequency, leading to falsified KPFM measurements. Additionally, we performed fast Fourier transform (FFT) analyses that

• intricate mixing of frequencies that may in some cases have a component at the detection frequency (cantilever resonance frequency). When this happens, the measured CPD deviates from the expected value. Additionally, we performed fast Fourier transform (FFT) analyses that match the results of the numerical

Field-controlled ultrafast magnetization dynamics in two-dimensional nanoscale ferromagnetic antidot arrays

• Anulekha De,
• Sucheta Mondal,
• Sourav Sahoo,
• Saswati Barman,
• Yoshichika Otani,
• Rajib Kumar Mitra and
• Anjan Barman

Beilstein J. Nanotechnol. 2018, 9, 1123–1134, doi:10.3762/bjnano.9.104

• negative delay and ultrafast demagnetization and subtracting a bi-exponential background. Fast Fourier transform (FFT) is performed over this background-subtracted oscillatory Kerr rotation data to obtain the power vs frequency plot. Figure 2a–f shows the representative background-subtracted experimental

Automated image segmentation-assisted flattening of atomic force microscopy images

• Yuliang Wang,
• Tongda Lu,
• Xiaolai Li and
• Huimin Wang

Beilstein J. Nanotechnol. 2018, 9, 975–985, doi:10.3762/bjnano.9.91

• , bowing, or other types of low frequency image artifacts [19][21][25][26][27]. Among the different types of artifacts, those showing specific frequencies can be eliminated through fast Fourier transform (FFT) methods [28]. However, for some other artifacts, such as tilting and bowing, flattening is

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

• ordering of such RA SAM is evidenced in Figure 1b, which shows periodically spaced ripples within the monolayer that are verified by the fast Fourier transform image inset. Both images in Figure 1b clearly indicate a 2.7 nm structural periodicity. This value is about twice the length of a RA molecule, and

• covering a graphite microplate substrate. (b) High-resolution AFM image (adhesion channel in peak force mode – see Experimental section) of the RA monolayer. The inset shows its fast Fourier transform, evidencing well-defined periodical RA ripples (periodicity: 2.7 ± 0.1 nm). (c) Schematic representation

BN/Ag hybrid nanomaterials with petal-like surfaces as catalysts and antibacterial agents

• Konstantin L. Firestein,
• Denis V. Leybo,
• Alexander E. Steinman,
• Andrey M. Kovalskii,
• Andrei T. Matveev,
• Anton M. Manakhov,
• Irina V. Sukhorukova,
• Pavel V. Slukin,
• Nadezda K. Fursova,
• Sergey G. Ignatov,
• Dmitri V. Golberg and
• Dmitry V. Shtansky

Beilstein J. Nanotechnol. 2018, 9, 250–261, doi:10.3762/bjnano.9.27

• with a size smaller than 6–9 nm consisted of small crystallites with coherent (twinned) or semi-coherent grain boundaries. The interplanar distances estimated from the fast Fourier transform (FFT) patterns (Figure 2c and 2f, insets) were d = 0.231 nm and d = 0.205 nm. These distances well correspond

Anchoring of a dye precursor on NiO(001) studied by non-contact atomic force microscopy

• Sara Freund,
• Antoine Hinaut,
• Nathalie Marinakis,
• Edwin C. Constable,
• Ernst Meyer,
• Catherine E. Housecroft and
• Thilo Glatzel

Beilstein J. Nanotechnol. 2018, 9, 242–249, doi:10.3762/bjnano.9.26

• using a constant frequency shift Δf1 [47][48]. Moreover, the Fast Fourier transform (Figure 2d) of Figure 2c, exhibits a cubic faced-centred lattice with a mesh parameter of 415 pm consistent with the theoretical bulk lattice constant of the NiO(001) surface (a = 417 pm). Figure 2e presents the profile

• ) shows the atomic rows while the torsional frequency shift (c) indicates that only one kind of atom can be imaged: one element appears as bright protrusion, the other as darker hole (scan parameters: = 7 nm, = 80 pm, Δf1 = −79 Hz). (d) Fast Fourier transform (FFT) of (c) shows the expected cubic

Comparative study of post-growth annealing of Cu(hfac)₂, Co₂(CO)₈ and Me₂Au(acac) metal precursors deposited by FEBID

• Marcos V. Puydinger dos Santos,
• Aleksandra Szkudlarek,
• Artur Rydosz,
• Carlos Guerra-Nuñez,
• Fanny Béron,
• Kleber R. Pirota,
• Stanislav Moshkalev,
• José Alexandre Diniz and
• Ivo Utke

Beilstein J. Nanotechnol. 2018, 9, 91–101, doi:10.3762/bjnano.9.11

• . In particular, the size of the metal agglomerates of all deposits was estimated from high-magnification SEM images (see Figure 1), using ImageJ software applying a fast Fourier transform (FFT) bandpass filter to enhance grain boundaries and a contrast-threshold algorithm to calculate the agglomerate

Intercalation of Si between MoS₂ layers

• Rik van Bremen,
• Qirong Yao,
• Soumya Banerjee,
• Deniz Cakir,
• Nuri Oncel and
• Harold J. W. Zandvliet

Beilstein J. Nanotechnol. 2017, 8, 1952–1960, doi:10.3762/bjnano.8.196

• arrow indicates an intrinsic defect, which is often found on MoS2. (b) High-resolution STM image of pristine MoS2. (c) Fast Fourier-transform of pristine MoS2 showing the hexagonal symmetry. (d) STM image taken after the deposition of 0.2 monolayers of Si. The arrows indicate a hill (bright) and a

Investigation of growth dynamics of carbon nanotubes

• Marianna V. Kharlamova

Beilstein J. Nanotechnol. 2017, 8, 826–856, doi:10.3762/bjnano.8.85

• in the fast Fourier transform (FFT) of Figure 3b to {111} planes, with the face-centered cubic (fcc) Ni lattice oriented close to the [110] axis. Figure 3c,d show ex situ HRTEM images of SWCNTs. Figure 3c presents an individual hemispherically capped SWCNT at a more progressed stage of growth. It is

Functionalized TiO₂ nanoparticles by single-step hydrothermal synthesis: the role of the silane coupling agents

• Antoine R. M. Dalod,
• Lars Henriksen,
• Tor Grande and
• Mari-Ann Einarsrud

Beilstein J. Nanotechnol. 2017, 8, 304–312, doi:10.3762/bjnano.8.33

• min. A droplet of the suspension was then placed on a carbon-coated copper TEM grid, which was set to rest until evaporation of the solvent. The dhkl distances were measured by extracting an area of interest from the HR-TEM images with fast Fourier transform analysis, and calculating the average

Impact of surface wettability on S-layer recrystallization: a real-time characterization by QCM-D

• Jagoba Iturri,
• Ana C. Vianna,
• Alberto Moreno-Cencerrado,
• Dietmar Pum,
• Uwe B. Sleytr and
• José Luis Toca-Herrera

Beilstein J. Nanotechnol. 2017, 8, 91–98, doi:10.3762/bjnano.8.10

• forming the S-layer on fluorosilane with visible physical boundaries between them (Figure 6b). The included fast Fourier transform (FFT) images contribute to visualize the uniformity of the crystalline layers. For SCWP the FFT appears as a well-defined square, resulting from a unique crystal orientation

• ) secondary cell-wall polymer and (b) fluorosilane-modified hydrophobic SiO2. Bottom insets show the fast Fourier transform images of the crystalline structures formed. Acknowledgements Part of this work was supported by the International Graduate School BioNanoTech (IGS) Program of the Federal Ministry for

Sub-nanosecond light-pulse generation with waveguide-coupled carbon nanotube transducers

• Felix Pyatkov,
• Svetlana Khasminskaya,
• Vadim Kovalyuk,
• Frank Hennrich,
• Manfred M. Kappes,
• Gregory N. Goltsman,
• Wolfram H. P. Pernice and
• Ralph Krupke

Beilstein J. Nanotechnol. 2017, 8, 38–44, doi:10.3762/bjnano.8.5

• setup. (b) Comparison of electrical pulses with TCSPC-histograms of optical pulses, measured at a grating coupler. (c) Sequence of electrical pulses (150 ps width, 2 GHz, 10 VDC and 3.3 Vpulse) as well as emission pulses. (d) Normalized fast Fourier transform (FFT) spectra of modulated CNTs, emitting at

Improved atomic force microscopy cantilever performance by partial reflective coating

• Zeno Schumacher,
• Yoichi Miyahara,
• Laure Aeschimann and
• Peter Grütter

Beilstein J. Nanotechnol. 2015, 6, 1450–1456, doi:10.3762/bjnano.6.150

• Fourier transform of the digitized photo diode signal. An 8th order Buttherworth low-pass filter with an appropriate cut-off frequency was used as an anti-aliasing filter. The resulting thermal vibration peak was fitted with a Lorentzian to extract its full width at half maximum from which the Q-factor

• stabilized and radio frequency modulated laser diode to reduce the mode-hopping noise of the laser beam [11]. The standard cantilever holder with a metal wire across the chip that clamps the cantilever was used for all measurements. The cantilever deflection noise density spectra were obtained by fast

Nanostructuring of GeTiO amorphous films by pulsed laser irradiation

• Valentin S. Teodorescu,
• Cornel Ghica,
• Adrian V. Maraloiu,
• Mihai Vlaicu,
• Andrei Kuncser,
• Magdalena L. Ciurea,
• Ionel Stavarache,
• Ana M. Lepadatu,
• Nicu D. Scarisoreanu,
• Andreea Andrei,
• Valentin Ion and
• Maria Dinescu

Beilstein J. Nanotechnol. 2015, 6, 893–900, doi:10.3762/bjnano.6.92

• irradiation continues for several minutes, the spherical crystallite becomes larger through a crystal growth process, as shown in Figure 9b. The fast Fourier transform (FFT) pattern inserted in Figure 9b shows a quadratic structure for the larger crystallite. By comparing the lattice fringes of the

Electromagnetic enhancement of ordered silver nanorod arrays evaluated by discrete dipole approximation

• Guoke Wei,
• Jinliang Wang and
• Yu Chen

Beilstein J. Nanotechnol. 2015, 6, 686–696, doi:10.3762/bjnano.6.69

• nanoarrays in vacuum employing the open-source code DDSCAT 7.2 developed by Draine and Flatau [19], which has the capability of performing efficient “near-field” calculations in and around the target by using fast-Fourier transform (FFT) methods [21]. The cubic grid spacing was 3 nm in all calculations. The

Synthesis, characterization, and growth simulations of Cu–Pt bimetallic nanoclusters

• Subarna Khanal,
• Ana Spitale,
• Nabraj Bhattarai,
• Daniel Bahena,
• J. Jesus Velazquez-Salazar,
• Sergio Mejía-Rosales,
• Marcelo M. Mariscal and
• Miguel José-Yacaman

Beilstein J. Nanotechnol. 2014, 5, 1371–1379, doi:10.3762/bjnano.5.150

• which we can clearly observe different atomic contrasts, related to the presence of Cu and Pt atoms. The inset of Figure 3a shows the corresponding fast Fourier transform (FFT). From the FFT it can be concluded that the crystal structure is fcc, and the zone axis in this case is [011]. Figure 3b was

• elemental line profiles along the green line across the nanostructure in (a), and (c) energy dispersive X-ray spectroscopy (EDX) spectrum of corresponding Cu–Pt bimetallic nanoparticles. High resolution HAADF-STEM image of (a) Cu–Pt bimetallic nanoparticle; the inset represents the fast Fourier transform

Effects of the preparation method on the structure and the visible-light photocatalytic activity of Ag₂CrO₄

• Difa Xu,
• Shaowen Cao,
• Jinfeng Zhang,
• Bei Cheng and
• Jiaguo Yu

Beilstein J. Nanotechnol. 2014, 5, 658–666, doi:10.3762/bjnano.5.77

• fringes with d spacings of 0.503 and 0.288 nm, which can be assigned to the (020) and (220), respectively, crystal planes of orthorhombic Ag2CrO4. The corresponding fast Fourier transform (FFT) image suggests a single-crystalline nature. This also indicates that the S-M sample is well-crystallized

Challenges and complexities of multifrequency atomic force microscopy in liquid environments

• Santiago D. Solares

Beilstein J. Nanotechnol. 2014, 5, 298–307, doi:10.3762/bjnano.5.33

• the fast Fourier transform to the results shown in (b). Typical eigenmode responses for bimodal and trimodal AFM operation in air with Q1 = 150, Q2 = 450, Q3 = 750, ν1 = 70 kHz, ν2 = 437.5 kHz, ν3 = 1.25 MHz and k1 = 2 N/m: (a) bimodal operation with A1 = 100 nm and A2 = 10 nm (A1/A2 = 10); (b

Dye-doped spheres with plasmonic semi-shells: Lasing modes and scattering at realistic gain levels

• Nikita Arnold,
• Boyang Ding,
• Calin Hrelescu and
• Thomas A. Klar

Beilstein J. Nanotechnol. 2013, 4, 974–987, doi:10.3762/bjnano.4.110

• σab. The extinction cross section is always defined as σex = σsc + σab, irrespectively of the sign of σab. Far-field patterns are calculated by the internal CST routines, which project the fields on the sides of the bounding box into the far-fields via fast Fourier transform. Adaptive meshing is a

A facile synthesis of a carbon-encapsulated Fe₃O₄ nanocomposite and its performance as anode in lithium-ion batteries

• Raju Prakash,
• Katharina Fanselau,
• Shuhua Ren,
• Tapan Kumar Mandal,
• Christian Kübel,
• Horst Hahn and
• Maximilian Fichtner

Beilstein J. Nanotechnol. 2013, 4, 699–704, doi:10.3762/bjnano.4.79

• bare Fe3O4 nanoparticles could also be observed (Figure S2 in Supporting Information File 1). Fast Fourier transform (FFT) analysis of various HRTEM images (of crystallites located inside or outside of carbon shells, see Figure S3 in Supporting Information File 1) reveal that the observed lattice

Polynomial force approximations and multifrequency atomic force microscopy

• Daniel Platz,
• Daniel Forchheimer,
• Erik A. Tholén and
• David B. Haviland

Beilstein J. Nanotechnol. 2013, 4, 352–360, doi:10.3762/bjnano.4.41

• approximates the inverse in a least-squares sense. The matrix can be rapidly computed from Equation 16 using the Fast Fourier Transform (FFT) algorithm. Therefore, Equation 19 provides an efficient way to determine the expansion coefficients of the the tip–surface force. However, special care should be taken

Towards 4-dimensional atomic force spectroscopy using the spectral inversion method

• Jeffrey C. Williams and
• Santiago D. Solares

Beilstein J. Nanotechnol. 2013, 4, 87–93, doi:10.3762/bjnano.4.10

• calculate its spectrum, Zp(ω), through application of the fast Fourier transform to a sequence of values of zp(t) recorded at regular intervals. Additionally, one can also obtain the spectrum of the driving force by rewriting Equation 2 as Next, one can apply the inverse fast Fourier transform to Fd(ω) in