Direct Imaging of Nanoparticle Embedding into PS Films

2002 ◽  
Vol 734 ◽  
Author(s):  
J.H. Teichroeb ◽  
J.A. Forrest
Keyword(s):  
Annealing Time ◽  
Sample Surface ◽  
Nano Particles ◽  
Silicon Substrates ◽  
Force Microscopy ◽  
Atomic Force ◽  
First Case ◽  
Large Numbers ◽  
20 Nm ◽  
Number Of Particles

ABSTRACTNon-contact Atomic Force Microscopy (AFM) was used to study the embedding of 10 nm and 20 nm gold nano-particles into the surface of polystyrene films spin-coated onto silicon substrates. The rate of embedding was determined by measuring the apparent nanosphere height as a function of annealing time. This was accomplished by two different methods. In the first case, each image (after a specific annealing time) is acquired at a different spot on the sample surface. In this case a fairly large (∼40) number of particles were imaged in order to have acceptable statistics. A second method involved the use of a kinematic mounting hot stage that allowed the same spot on the sample to be imaged at each time. This allows the same final precision without the same necessity for imaging large numbers of particles. The results indicate that sub nm resolution is easily obtainable with either technique.

ANNEALING TIME EFFECT ON NANOSTRUCTURED n-ZnO/p-Si HETEROJUNCTION PHOTODETECTOR PERFORMANCE

2015 ◽  
Vol 22 (02) ◽  
pp. 1550027 ◽  
Author(s):  
NADIR. F. HABUBI ◽  
RAID. A. ISMAIL ◽  
WALID K. HAMOUDI ◽  
HASSAM. R. ABID
Keyword(s):  
Annealing Time ◽  
Silicon Substrates ◽  
X Ray Diffraction ◽  
Zno Nps ◽  
Force Microscopy ◽  
Atomic Force ◽  
Junction Type ◽  
P Type ◽  
Quartz Substrates ◽  
Two Peaks

In this work, n- ZnO /p- Si heterojunction photodetectors were prepared by drop casting of ZnO nanoparticles (NPs) on single crystal p-type silicon substrates, followed by (15–60) min; step-annealing at 600∘C. Structural, electrical, and optical properties of the ZnO NPs films deposited on quartz substrates were studied as a function of annealing time. X-ray diffraction studies showed a polycrystalline, hexagonal wurtizte nanostructured ZnO with preferential orientation along the (100) plane. Atomic force microscopy measurements showed an average ZnO grain size within the range of 75.9 nm–99.9 nm with a corresponding root mean square (RMS) surface roughness between 0.51 nm–2.16 nm. Dark and under illumination current–voltage (I–V) characteristics of the n- ZnO /p- Si heterojunction photodetectors showed an improving rectification ratio and a decreasing saturation current at longer annealing time with an ideality factor of 3 obtained at 60 min annealing time. Capacitance–voltage (C–V) characteristics of heterojunctions were investigated in order to estimate the built-in-voltage and junction type. The photodetectors, fabricated at optimum annealing time, exhibited good linearity characteristics. Maximum sensitivity was obtained when ZnO / Si heterojunctions were annealed at 60 min. Two peaks of response, located at 650 nm and 850 nm, were observed with sensitivities of 0.12–0.19 A/W and 0.18–0.39 A/W, respectively. Detectivity of the photodetectors as function of annealing time was estimated.

scholarly journals Stereometric analysis of Ta2O5 thin films

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Dinara Sobola ◽  
Pavel Kaspar ◽  
Jindrich Oulehla ◽  
Ştefan Ţălu ◽  
Nikola Papež
Keyword(s):  
Thin Films ◽  
Three Dimensional ◽  
Theoretical Models ◽  
Electron Beam Evaporation ◽  
Tantalum Pentoxide ◽  
Silicon Substrates ◽  
Force Microscopy ◽  
Atomic Force ◽  
20 Nm ◽  
Reference Samples

AbstractThe purpose of this work is the study of the correlation between the thickness of tantalum pentoxide thin films and their three-dimensional (3D) micromorphology. The samples were prepared on silicon substrates by electron beam evaporation. The differences in surface structure of the processed and reference samples were investigated. Compositional studies were performed by energy-dispersive X-ray spectroscopy. Stereometric analysis was carried out on the basis of atomic force microscopy (AFM) data, for tantalum pentoxide samples with 20 nm, 40 nm, 60 nm, 80 nm and 100 nm thicknesses. These methods are frequently used in describing experimental data of surface nanomorphology of Ta2O5. The results can be used to validate theoretical models for prediction or correlation of nanotexture surface parameters.

ATOMIC FORCE MICROSCOPY AND XRD ANALYSIS OF SILVER FILMS DEPOSITED BY THERMAL EVAPORATION

2006 ◽  
Vol 20 (02) ◽  
pp. 217-231 ◽  
Author(s):  
MUHAMMAD MAQBOOL ◽  
TAHIRZEB KHAN
Keyword(s):  
Atomic Force Microscopy ◽  
Grain Size ◽  
Surface Characterization ◽  
Room Temperature ◽  
Thermal Evaporation ◽  
Xrd Analysis ◽  
Force Microscopy ◽  
Atomic Force ◽  
Average Grain Size ◽  
20 Nm

Thin films of pure silver were deposited on glass substrate by thermal evaporation process at room temperature. Surface characterization of the films was performed using X-ray diffraction (XRD) and atomic force microscopy (AFM). Thickness of the films varied between 20 nm and 72.8 nm. XRD analysis provided a sharp peak at 38.75° from silver. These results indicated that the films deposited on glass substrates at room temperature are crystalline. Three-dimension and top view pictures of the films were obtained by AFM to study the grain size and its dependency on various factors. Average grain size increased with the thickness of the deposited films. A minimum grain size of 8 nm was obtained for 20 nm thick films, reaching 41.9 nm when the film size reaches 60 nm. Grain size was calculated from the information provided by the XRD spectrum and averaging method. We could not find any sequential variation in the grain size with the growth rate.

scholarly journals Influence of the Microstructure and Optical Constants on Plasmonic Properties of Copper Nanolayers

Materials ◽  
2021 ◽  
Vol 14 (23) ◽  
pp. 7292
Author(s):  
Tomasz Rerek ◽  
Beata Derkowska-Zielinska ◽  
Marek Trzcinski ◽  
Robert Szczesny ◽  
Mieczyslaw K. Naparty ◽  
...  
Keyword(s):  
Surface Plasmon ◽  
Photoelectron Spectroscopy ◽  
Surface Plasmon Polariton ◽  
Optical Constants ◽  
Localized Surface Plasmon ◽  
Silicon Substrates ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force ◽  
Plasmon Polariton

Copper layers with thicknesses of 12, 25, and 35 nm were thermally evaporated on silicon substrates (Si(100)) with two different deposition rates 0.5 and 5.0 Å/s. The microstructure of produced coatings was studied using atomic force microscopy (AFM) and powder X-ray diffractometer (XRD). Ellipsometric measurements were used to determine the effective dielectric functions <ε˜> as well as the quality indicators of the localized surface plasmon (LSP) and the surface plasmon polariton (SPP). The composition and purity of the produced films were analysed using X-ray photoelectron spectroscopy (XPS).

Spectroscopic Characterization of Flame-Generated 2-D Carbon Nano-Disks

2015 ◽  
Vol 1726 ◽  
Author(s):  
Patrizia Minutolo ◽  
Mario Commodo ◽  
Gianluigi De Falco ◽  
Rosanna Larciprete ◽  
Andrea D'Anna
Keyword(s):  
Carbon Nanostructures ◽  
Functional Materials ◽  
Building Blocks ◽  
Spectroscopic Characterization ◽  
Molecular Compound ◽  
Force Microscopy ◽  
Atomic Force ◽  
Thin Carbon ◽  
On Line ◽  
20 Nm

ABSTRACTIn this work we produce atomically thin carbon nanostructures which have a disk-like shape when deposited on a substrate. These nanostructures have intermediate characteristics between a graphene island and a molecular compound and have the potentiality to be used either as they are, or to become building blocks for functional materials or to be manipulated and engineered into composite layered structures.The carbon nanostructures are produced in a premixed ethylene/air flame with a slight excess of fuel with respect to the stoichiometric value. The size distribution of the produced compounds in aerosol phase has been measured on line by means of a differential mobility analyzer (DMA) and topographic images of the structures deposited on mica disks were obtained by Atomic Force Microscopy. Raman spectroscopy and XPS have been used to characterize their structure and the electronic and optical properties were obtained combining on-line photoionization measurements with Cyclic Voltammetry, light absorption and photoluminescence.When deposited on the mica substrate the carbon compounds assume the shape of an atomically thin disk with in plane diameter of about 20 nm. Carbon nano-disks consist of a network of small aromatic island with in plane length, La, of about 1 nm. Raman spectra evidence a significant amount of disorder which is in a large part due to the quantum confinement in the aromatic islands. Nano-disks contain small percentage of sp3 and the O/C ratio is lower than 6%. They furthermore present interesting UV and visible photoluminescence properties.

Growth Front Roughening of Room Temperature Deposited Oligomer Thin Films

2000 ◽  
Vol 648 ◽  
Author(s):  
D. Tsamouras ◽  
G. Palasantzas ◽  
J. Th. M. De Hosson ◽  
G. Hadziioannou
Keyword(s):  
Thin Films ◽  
Film Thickness ◽  
Room Temperature ◽  
Growth Front ◽  
Silicon Substrates ◽  
Height Distribution ◽  
Force Microscopy ◽  
Atomic Force ◽  
Roughness Amplitude ◽  
Non Gaussian

AbstractGrowth front scaling aspects are investigated for PPV-type oligomer thin films vapor- deposited onto silicon substrates at room temperature. For film thickness d~15-300 nm, commonly used in optoelectronic devices, correlation function measurement by atomic force microscopy yields roughness exponents in the range H=0.45±0.04, and an rms roughness amplitude which evolves with film thickness as a power law σ∝ dβ with β=0.28±0.05. The non-Gaussian height distribution and the measured scaling exponents (H and β) suggest a roughening mechanism close to that described by the Kardar-Parisi-Zhang scenario.

scholarly journals UV Sensitivity of Indium-Zinc Oxide Nanofibers

2018 ◽  
Vol 2018 ◽  
pp. 1-6 ◽  
Author(s):  
Nadezhda Markova ◽  
Olga Berezina ◽  
Nikolay Avdeev ◽  
Alexander Pergament
Keyword(s):  
Zinc Oxide ◽  
Indium Content ◽  
Silicon Substrates ◽  
X Ray Diffraction ◽  
Force Microscopy ◽  
Atomic Force ◽  
Indium Zinc Oxide ◽  
Electrospinning Method ◽  
Recovery Times ◽  
Response And Recovery

Indium-zinc oxide (IZO) nanofiber matrices are synthesized on SiO2-covered silicon substrates by the electrospinning method. The nanofibers’ dimensions, morphology, and crystalline structure are characterized by scanning electron microscopy, atomic force microscopy, and X-ray diffraction. The results of studying the electrical properties of nanofibers, as well as their sensitivity to UV radiation depending on the In-to-Zn concentration ratio, are presented. It is shown that the highest sensitivity to UV is observed at the indium content of about 50 atomic %. The photocurrent increment with respect to the dark current is more than 4 orders of magnitude. The response and recovery times are 60 and 500 sec, respectively. The results obtained suggest that IZO nanofibers can find application as UV sensors with improved characteristics.

Characterization and Optimization of The Tco/a-Si:H(,B) Interface for Solar Cells by In-Situ Ellipsometry and Sims/XPS Depth Profiling

1994 ◽  
Vol 336 ◽  
Author(s):  
H.N. Wanka ◽  
E. Lotter ◽  
M.B. Schubert
Keyword(s):  
Solar Cells ◽  
Light Trapping ◽  
Hydrogen Plasma ◽  
Depth Profiling ◽  
Trapping Efficiency ◽  
Force Microscopy ◽  
Hydrogen Plasmas ◽  
Atomic Force ◽  
20 Nm

ABSTRACTThe chemical reactions at the surface of transparent conductive oxides (SnO2, ITO and ZnO) have been studied in silane and hydrogen plasmas by in-situ ellipsometry and by SIMS as well as XPS depth profiling. SIMS and XPS of the interface reveal an increasing amount of metallic phases upon lowering a-Si:H growth rates (controlled by plasma power), indicating that the ion and radical impact is more than compensated by protecting the surface by a rapidly growing a-Si:H film. Hence, optical transmission of TCO films as well as the efficiency of solar cells can be improved if the first few nanometers of the p-layer are grown at higher rates. Comparing a-Si:H deposition on top of different TCOs, reduction effects on ITO and SnO2 have been detected whereas ZnO appeared to be chemically stable. Therefore an additional shielding of the SnO2 surface by a thin ZnO layer has been investigated in greater detail. Small amounts of H are detected close to the ZnO surface by SIMS after hydrogen plasma treatment, but no significant changes occur to the optical and electrical properties. In-situ ellipsometry indicates that a ZnO layer as thin as 20 nm completely protects SnO2 from being reduced to metallic phases. This provides for shielding of textured TCOs, and hence rising solar cell efficiencies, too. Regarding light trapping efficiency we additionally investigated the smoothing of initial TCO texture when growing a-Si:H on top by combining atomic force microscopy and spectroscopie ellipsometry.

SURFACE PLASMON ENHANCED OPTICAL SECOND HARMONIC GENERATION IN ULTRA-THIN METALLIC FILMS

1999 ◽  
Vol 08 (04) ◽  
pp. 503-518 ◽  
Author(s):  
JUH-TZENG LUE ◽  
CHIA-SHY CHANG
Keyword(s):  
Second Harmonic ◽  
Angular Position ◽  
Field Enhancement ◽  
Surface Scattering ◽  
Metallic Films ◽  
Silver Films ◽  
Force Microscopy ◽  
Atomic Force ◽  
Peak Intensity ◽  
20 Nm

Internal reflection of second-harmonic generations from silver films with thickness ranging from 5 nm to 50 nm are enhanced by the excitation of surface plasmons under Kretschmann configuration. Enhancement of the SHG was observed at a film thickness of 20 nm resulting from the field enhancement of granular structure. For thinner films, the surface reveals disconnected islands as inspected by the atomic force microscopy. The incident angular position to find the peak intensity and the change of linewidth of the SHG can almost satisfactorily be predicted by the theory based on surface scattering.

Anisotropic Behaviour of Surface Roughening in Lattice Mismatched Heteroepitaxial Thin Films

1996 ◽  
Vol 436 ◽  
Author(s):  
Cengiz S. Ozkan ◽  
William D. Nix ◽  
Huajian Gao
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Transmission Electron Microscopy ◽  
Lattice Mismatch ◽  
Surface Roughening ◽  
Silicon Substrates ◽  
Force Microscopy ◽  
Atomic Force ◽  
Transmission Electron ◽  
Annealing Experiments

AbstractHeteroepitaxial Si1-xGex. thin films deposited on silicon substrates exhibit surface roughening via surface diffusion under the effect of a compressive stress which is caused by a lattice mismatch. In these films, surface roughening can take place in the form of ridges which can be aligned along <100> or <110> directions, depending on the film thickness. In this paper, we investigate this anisotropic dependence of surface roughening and present an analysis of it. We have studied the surface roughening behaviour of 18% Ge and 22% Ge thin films subjected to controlled annealing experiments. Transmission electron microscopy and atomic force microscopy have been used to study the morphology and microstructure of the surface ridges and the dislocations that form during annealing.

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