scholarly journals The Effect of the Indium(III) Phthalocyanine Chloride Films on the Behavior of Flexible Devices of Flat and Disperse Heterojunction

Coatings ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 673
Author(s):  
María Elena Sánchez-Vergara ◽  
Raquel Carrera-Téllez ◽  
Paulina Smith-Ruiz ◽  
Citlalli Rios ◽  
Roberto Salcedo
Keyword(s):  
Layer Growth ◽  
Visible Range ◽  
Layer By Layer ◽  
Spectral Absorption ◽  
X Ray ◽  
Flexible Devices ◽  
Vis Spectroscopy ◽  
Optical Bandgaps ◽  
Vacuum Deposition Method ◽  
Donor Species

By means of flat-heterojunction structures based on small semiconductor molecules (MSCs), an analysis of the indium(III) phthalocyanine chloride (In(III)PcCl) film as a constituent of optoelectronic devices was performed. The study included the behavior of In(III)PcCl playing three different roles: a donor species, an electronic acceptor, and a hole layer carrier. The flat-heterojunction structures were prepared by vacuum deposition method that permits a controlled layer-by-layer growth of high purity films. The investigated structures were characterized by scanning electron microscopy (SEM), Energy-dispersive X-ray spectroscopy (EDS), UV-vis spectroscopy and optical bandgaps were obtained by Tauc’s and Cody’s methods. As the structures exhibit a large spectral absorption in the visible range, they were incorporated into flat-heterojunction devices based on flexible and rigid substrates. However, during the synthesis of those structures, the disperse heterojunction arrangement was found and indeed it showed to be more efficient than the initial flat-heterojunction. In order to complement these results, disperse heterojunction arrangement structure as well as its bandgap value were obtained by DFT calculations. Finally, the electronic behavior of both fabricated devices, disperse heterojunction and flat-heterojunction were compared.

Synthesis and Characterization of Zn Oxide Hexagonal Nano-Pole Films on Quartz Glass Substrate

2009 ◽  
Vol 7 (1) ◽  
Author(s):  
Jie Chen ◽  
Jun Wang
Keyword(s):  
Growth Mechanism ◽  
Quartz Glass ◽  
Photoelectron Spectroscopy ◽  
Glass Substrate ◽  
Sol Gel ◽  
Layer Growth ◽  
Layer By Layer ◽  
Quartz Glass Substrate ◽  
Wurtzite Phase ◽  
X Ray

Hexagon-shaped Zn oxide nano-pole films with terraces and steps have been successfully fabricated by means of a combined approach involving sol-gel process, high-temperature heat treatment, and the hydrothermal method. The surface chemistry and morphological features of the films were characterized by means of x-ray photoelectron spectroscopy and scanning electron microcopy. All the diffraction peaks in x-ray diffraction pattern match with those of the hexagonal wurtzite phase of Zn oxide. Transmittance measurements show that the optical transmittance of the sample synthesized at 520°C on quartz glass substrate is the highest, reaching about 65% in the visible-light region. Based on the detailed structural characterization and the nucleation-growth kinetics, we find that the whole crystallization process of wurtzite Zn oxide nano-poles includes nanocatalysis and layer-by-layer growth mechanism. The present study provides an important understanding of the growth mechanism for nano-pole synthesis of Zn oxide and related materials.

scholarly journals Initial Growth and Crystallization Onset of Plasma Enhanced-Atomic Layer Deposited ZnO

Crystals ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 291
Author(s):  
Alberto Perrotta ◽  
Julian Pilz ◽  
Roland Resel ◽  
Oliver Werzer ◽  
Anna Maria Coclite
Keyword(s):  
Atomic Layer ◽  
Layer Growth ◽  
Growth Mode ◽  
Ex Situ ◽  
Native Oxide ◽  
Layer By Layer ◽  
Initial Growth ◽  
Island Growth ◽  
X Ray ◽  
Crystallization Onset

Direct plasma enhanced-atomic layer deposition (PE-ALD) is adopted for the growth of ZnO on c-Si with native oxide at room temperature. The initial stages of growth both in terms of thickness evolution and crystallization onset are followed ex-situ by a combination of spectroscopic ellipsometry and X-ray based techniques (diffraction, reflectivity, and fluorescence). Differently from the growth mode usually reported for thermal ALD ZnO (i.e., substrate-inhibited island growth), the effect of plasma surface activation resulted in a substrate-enhanced island growth. A transient region of accelerated island formation was found within the first 2 nm of deposition, resulting in the growth of amorphous ZnO as witnessed with grazing incidence X-ray diffraction. After the islands coalesced and a continuous layer formed, the first crystallites were found to grow, starting the layer-by-layer growth mode. High-temperature ALD ZnO layers were also investigated in terms of crystallization onset, showing that layers are amorphous up to a thickness of 3 nm, irrespective of the deposition temperature and growth orientation.

Surfactant-Mediated Growth of Ge/Si(001) Interface Studied by XPD

1998 ◽  
Vol 05 (01) ◽  
pp. 157-161 ◽  
Author(s):  
R. Gunnella ◽  
P. Castrucci ◽  
N. Pinto ◽  
P. Cucculelli ◽  
I. Davoli ◽  
...  
Keyword(s):  
High Temperature ◽  
Auger Electron ◽  
Layer Growth ◽  
Layer By Layer ◽  
Growth Morphology ◽  
High Quality ◽  
X Ray ◽  
Photoelectron Diffraction ◽  
Quality Degradation ◽  
Cap Layer

The influence of Sb as a surfactant on the formation of Si/Ge interface is studied by means of XPD (X-ray photoelectron diffraction) and AED (Auger electron diffraction) from Ge and Si core levels. The technique employed is particularly suitable for checking the film tetragonal distortion, the growth morphology and the sharpness of the interface. We found a layer by layer growth mode for 3 ML of Ge on Si(001) and related values of strain of the film close to the value predicted by the elastic theory which enforces the use of such a surfactant to obtain high quality and sharp heterostructures. In addition, studying the influence of 3 ML of the Si cap layer on the 3 ML Ge, we obtain no indication of Ge segregation into the Si cap layer. Finally, evidences of quality degradation after high temperature (T > 600° C ) annealing are shown.

scholarly journals Influence of Annealing on Properties of Spray Deposited ZnO Thin Films

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Kalyani Nadarajah ◽  
Ching Yern Chee ◽  
Chou Yong Tan
Keyword(s):  
Thin Films ◽  
Electrical Resistivity ◽  
Spray Pyrolysis Technique ◽  
Hexagonal Wurtzite Structure ◽  
Ambient Air ◽  
Zno Thin Films ◽  
Visible Range ◽  
X Ray ◽  
Average Grain Size ◽  
Vis Spectroscopy

Zinc Oxide (ZnO) thin films were deposited on glass substrates via the spray pyrolysis technique. The films were subsequently annealed in ambient air from 300°C to 500°C. The morphology and structural properties of the thin films were studied by field emission scanning electron microscope (FESEM), atomic force microscopy (AFM), and X-ray diffractometry (XRD) techniques. Electrical resistivity of the thin films was measured using a data acquisition unit. The optical properties of the films were characterized by UV-vis spectroscopy and photoluminescence (PL) technique. X-ray diffraction data showed that the films were grown in the (002) direction with a hexagonal wurtzite structure. The average grain size ranged from 15 to 27 nm. Increasing annealing temperatures resulted in larger grain sizes and higher crystallinity, with the surface roughness of annealed films being more than twice if compared to unannealed film. The electrical resistivity of the films decreased with the increasing annealing temperature. The UV and visible band emissions were observed in the photoluminescence spectra, due to exciton and defect-related emissions, respectively. The transmission values of the films were as high as 90% within the visible range (400–700 nm).

Growth of CaFeOX/LaFeO3 Superlattice on SrTiO3(100) Substrates

2011 ◽  
Vol 1292 ◽  
Author(s):  
Nobuyuki Iwata ◽  
Mark Huijben ◽  
Guus Rijnders ◽  
Hiroshi Yamamoto ◽  
Dave H. A. Blank
Keyword(s):  
Thin Films ◽  
Pulsed Laser Deposition ◽  
Pulsed Laser ◽  
Layer Growth ◽  
Laser Deposition ◽  
Growth Mode ◽  
Layer By Layer ◽  
X Ray Diffraction ◽  
Reciprocal Space Mapping ◽  
X Ray

ABSTRACTThe CaFeOX(CFO) and LaFeO3(LFO) thin films as well as superlattices were fabricated on SrTiO3(100) substrates by pulsed laser deposition (PLD) method. The tetragonal LFO film grew with layer-by-layer growth mode until approximately 40 layers. In the case of CFO, initial three layers showed layer-by-layer growth, and afterward the growth mode was transferred to two layers-by-two layers (TLTL) growth mode. The RHEED oscillation was observed until the end of the growth, approximately 50nm. Orthorhombic twin CaFeO2.5 (CFO2.5) structure was obtained. However, it is expected that the initial three CFO layers are CaFeO3 (CFO3) with the valence of Fe4+. The CFO and LFO superlattice showed a step-terraces surface, and the superlattice satellite peaks in a 2θ-θ and reciprocal space mapping (RSM) x-ray diffraction (XRD) measurements, indicating that the clear interfaces were fabricated.

A SURFACE X-RAY DIFFRACTION STUDY OF THE GROWTH OF ULTRATHIN LAYERS OF Fe ON Cu(001)

1994 ◽  
Vol 01 (04) ◽  
pp. 631-634 ◽  
Author(s):  
M.A. JAMES ◽  
C. NORRIS ◽  
C.L. NICKLIN ◽  
R.G. VAN SILFHOUT ◽  
P.B. HOWES ◽  
...  
Keyword(s):  
Layer Growth ◽  
Detailed Knowledge ◽  
Exact Nature ◽  
Layer By Layer ◽  
X Ray Diffraction ◽  
Iron Films ◽  
X Ray ◽  
Diffusion Limited ◽  
Ultrathin Layers ◽  
Fcc Phase

Although it is well known that the γ (fcc) phase of Fe can be stabilised on Cu(001) single crystal substrates, there is still considerable disagreement about the exact nature of the growth mode and the structures that evolve with increasing film thickness. A detailed knowledge of the structure and morphology is essential for a complete understanding of the magnetic properties of ultrathin iron films. Surface X-ray diffraction measurements, recorded in real time during deposition of Fe deposition on Cu(001), are presented. At room temperature, well-defined layer-by-layer growth, with no significant agglomeration of iron, was observed. The specular intensity of the X-ray beam varied parabolically with coverage, as predicted by kinematical theory. Intensity oscillations were observed up to 15 Fe monolayers, at which coverage relaxation to the α (bcc) phase was confirmed. At 85 K the growth is diffusion limited.

A compact UHV X-ray diffractometer for studying surfaces and interfaces

1998 ◽  
Vol 5 (3) ◽  
pp. 887-889
Author(s):  
Yoshikazu Fujii ◽  
Takeshi Nakamura ◽  
Mutsumi Kai ◽  
Kentaroh Yoshida
Keyword(s):  
High Vacuum ◽  
Layer Growth ◽  
Ultra High Vacuum ◽  
Layer By Layer ◽  
Crystal Surfaces ◽  
X Ray ◽  
Surfaces And Interfaces ◽  
Optical Table ◽  
Specimen Orientation

A compact ultra-high-vacuum (UHV) X-ray diffractometer for surface glancing X-ray scattering has been constructed. All the equipment, including a rotating-anode source of 18 kW and a UHV specimen chamber, is arranged on one optical table of dimensions 70 × 90 cm. The specimen chamber is 14 cm in diameter and 20 cm high and can be evacuated up to 3 × 10−8 Pa. It is equipped with two Be windows of thicknesses 0.2 and 0.4 mm. Specimen orientation in the vacuum is controlled from the outside. The specimen can be heated up to 773 K. The chamber has two evaporation cells and can be used for in situ observations of growing crystal surfaces. Using this instrument, we observed a mechanically polished Ag surface and successfully made an in situ observation of the layer-by-layer growth of a PbSe(111) surface. The instrument will be useful for preliminary experiments using laboratory sources, prior to final measurements at synchrotron radiation facilities.

A MODEL OF STRUCTURAL DISORDER IN (Ba2Cu2O4+x)/(CaCuO2)n SUPERLATTICES

2000 ◽  
Vol 14 (25n27) ◽  
pp. 2719-2724
Author(s):  
G. PASQUINI ◽  
G. BALESTRINO ◽  
S. LAVANGA ◽  
P. G. MEDAGLIA ◽  
G. PETROCELLI ◽  
...  
Keyword(s):  
Structural Disorder ◽  
Layer Growth ◽  
Internal Stresses ◽  
Layer By Layer ◽  
Mixed Composition ◽  
X Ray ◽  
Order Of Magnitude ◽  
Random Disorder ◽  
Kinematical Approach

The structural disorder in ( Ba 2 Cu 2 O 4+x )/( CaCuO 2) n superlattices with ultrathin individual layers was investigated. Numerical simulations of x-ray spectra were carried out following a kinematical approach in a simplified model structure. The model assumes a two-dimensional layer by layer growth in which mixed composition layers can be corrugated to adjust the internal stresses due to the large mismatch between the constituent oxides. An additional random disorder is added to take into account the experimental dispersion in the amount of material deposited in each iteration. The model was successfully used to simulate x-ray spectra for samples with non integer n ranging from 2 to 16, grown in optimal conditions to obtain a superconducting behavior. The same model was used to simulate spectra of samples grown at lower pressures monitored with in-situ RHEED diagnostic. In this case, random disorder results more than one order of magnitude smaller.

Optical and Electrical Characteristic of Layer-by-Layer Sol-Gel Spin Coated Nanoparticles ZnO Thin Films

2011 ◽  
Vol 364 ◽  
pp. 149-153 ◽  
Author(s):  
Shafinaz Sobihana Shariffudin ◽  
Farliana Samat Farah ◽  
Sukreen Hana Herman ◽  
Mohamad Rusop
Keyword(s):  
Thin Films ◽  
Sol Gel ◽  
Reference Sample ◽  
Zno Thin Films ◽  
Visible Range ◽  
Zno Films ◽  
Layer By Layer ◽  
Voltage Measurement ◽  
Vis Spectroscopy ◽  
Reference Samples

Transparent nanoparticles ZnO thin films have been deposited on glass substrates using sol-gel spin coating technique. 0.35M sol were prepared by dissolving zinc acetate dehydrate in 2-methoxyethanol with monoethanolamine as the stabilizer. In this paper, a novel method called layer-by-layer is introduced, where the thin film is not only dried after each layer is spin-coated, but also directly annealed at 500°C to improve the electrical and optical properties of the films. Samples without annealing were also prepared as the reference sample. ZnO thin films were characterized using current-voltage measurement, UV-Vis spectroscopy and photoluminescence spectroscopy. The results revealed that layer-by-layer ZnO thin films have lower resistivity compared to the reference samples with a maximum value of 0.77Ω.cm for ZnO films deposited with 2 layers. Transmittance spectra show that the films were transparent in the visible range above 400nm with range of 86%-98% for the layer-by-layer ZnO films. The optical band gaps were between 3.2 to 3.3eV for both layer-by-layer and the reference samples. PL spectra indicate that layer-by-layer method improves the crystallinity of the films.

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