scholarly journals Morphology and Spectroscopic Ellipsometry of PMMA Thin Films

2017 ◽  
Vol 9 (2) ◽  
pp. 5 ◽  
Author(s):  
H. M. El-Nasser
Keyword(s):  
Thin Films ◽  
Optical Properties ◽  
Spectroscopic Ellipsometry ◽  
Silicon Substrates ◽  
Analysis Method ◽  
Force Microscopy ◽  
Atomic Force ◽  
Mean Grain Size ◽  
Multiple Sample ◽  
Ellipsometry Data

The morphology and optical properties of PMMA thin films deposited on silicon substrates were investigated. The spin coated films were characterized by atomic force microscopy and spectroscopic ellipsometry. Regardless that, the samples were deposited at different coating speeds, the surface structures of all PMMA thin films were consistent, and found to be relatively smooth, with a mean grain size in the range of 13-25 nm. The refractive index as well as the extinction coefficient of the films was determined using spectroscopic ellipsometry data over the wavelength range 380-750 nm. For this purpose, we used the Cauchy dispersion relation in order to represent PMMA layers, and then models were built by adding a roughness layer, which simply corrects any possible deviation from planarity. Besides, the thicknesses of all four films were calculated simultaneously based on multiple sample analysis method. By using this method, optical properties were coupled in such way that, the optical constants for all samples were assumed to be identical.

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.

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.

scholarly journals Optical and Morphological Studies of Thermally Evaporated PTCDI-C8 Thin Films for Organic Solar Cell Applications

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Ronak Rahimi ◽  
V. Narang ◽  
D. Korakakis
Keyword(s):  
Thin Films ◽  
Silicon Substrates ◽  
High Electron ◽  
Ambient Conditions ◽  
Force Microscopy ◽  
Morphological Studies ◽  
Atomic Force ◽  
Organic Semiconductor Devices ◽  
Thermal Evaporator ◽  
High Degree

PTCDI-C8 due to its relatively high photosensitivity and high electron mobility has attracted much attention in organic semiconductor devices. In this work, thin films of PTCDI-C8 with different thicknesses were deposited on silicon substrates with native silicon dioxide using a vacuum thermal evaporator. Several material characterization techniques have been utilized to evaluate the structure, morphology, and optical properties of these films. Their optical constants (refractive index and extinction coefficient) have been extracted from the spectroscopic ellipsometry (SE). X-ray reflectivity (XRR) and atomic force microscopy (AFM) were employed to determine the morphology and structure as well as the thickness and roughness of the PTCDI-C8 thin films. These films revealed a high degree of structural ordering within the layers. All the experimental measurements were performed under ambient conditions. PTCDI-C8 films have shown to endure ambient condition which allows pots-deposition characterization.

Structural and Optical Properties of PbI2 Thin Films to Fabricate Perovskite Solar Cells

2020 ◽  
Vol 398 ◽  
pp. 140-146
Author(s):  
Kawther A. Khalaph ◽  
Zainab J. Shanan ◽  
Aqel Mashot Jafar ◽  
Falah Mustafa Al-Attar
Keyword(s):  
Thin Films ◽  
Optical Properties ◽  
Energy Gap ◽  
Perovskite Solar Cells ◽  
Lead Iodide ◽  
Structural And Optical Properties ◽  
Solar Cell Application ◽  
Force Microscopy ◽  
Glass Substrates ◽  
Atomic Force

Recently, lead iodide is the most materials employment in the perovskite solar cell application. This paper has studied the character of preparation, structural and optical properties of pbI2 materials. Structural properties are included investigation of the measurements X-Ray Diffraction (XRD), Scan Electron Microscopy (SEM), Fourier Transform InfraRed spectroscopy (FTIR) and Atomic Force Microscopy (AFM) tests to the PbI2 thin films samples. Optical properties are included the investigation UV-Vis test of the thin film samples deposited on glass substrates and investigated the Absorption, Transmittance and evaluated energy gap (Eg = 2.3 eV).

Electroplated CuO Thin Films from High Alkaline Solutions

2011 ◽  
Vol 15 (1) ◽  
pp. 49-55
Author(s):  
V. Dhanasekaran ◽  
T. Mahalingam ◽  
S. Rajendran ◽  
Jin Koo Rhee ◽  
D. Eapen
Keyword(s):  
Thin Films ◽  
Optical Properties ◽  
Film Thickness ◽  
Structural Characteristics ◽  
Band Gap Energy ◽  
Alkaline Solutions ◽  
X Ray Diffraction ◽  
Force Microscopy ◽  
Microstructural Parameters ◽  
Atomic Force

CuO thin films were coated on ITO substrates by an electrodeposition route through potentiostatic mode. The electrodeposited CuO thin films were characterized and the role of copper sulphate concentration on the structural, morphological and optical properties of the CuO films was studied. Film thickness was measured by a stylus profilometer and found to be in the range between 800 and 1400 nm. The structural characteristics studies were carried out using X-ray diffraction and found that the films are polycrystalline in nature with a cubic structure. The preferential orientation of CuO thin films is found to be along (111) plane. The estimated microstructural parameters revealed that the crystallite size increases whereas the number of crystallites per unit area decreases with increasing film thickness. SEM studies show that the grain sizes of CuO thin films vary between 100 and 150 nm and also morphologies revealed that the electrodeposited CuO exhibits uniformity in size and shape. The surface roughness is estimated 15 nm of the CuO film were studied by atomic force microscopy. Optical properties of the films were analyzed from absorption and transmittance studies. The optical band gap energy was determined to be 1.5 eV from absorption coefficient. The variation of refractive index (n), extinction coefficient (k), with wavelength was studied and the results are discussed.

EFFECT OF SUBSTRATE TEMPERATURE ON THE STRUCTURAL AND THE OPTICAL PROPERTIES OF CdTe (100) EPITAXIAL FILMS GROWN ON GaAs (100) SUBSTRATES

2007 ◽  
Vol 14 (04) ◽  
pp. 755-759 ◽  
Author(s):  
D. U. LEE ◽  
J. H. JUNG ◽  
T. W. KIM ◽  
H. S. LEE ◽  
H. L. PARK ◽  
...  
Keyword(s):  
Thin Films ◽  
Optical Properties ◽  
Substrate Temperature ◽  
Misfit Dislocations ◽  
X Ray Diffraction ◽  
Force Microscopy ◽  
Atomic Force ◽  
Transmission Electron ◽  
Cdte Thin Films ◽  
Xrd Patterns

CdTe thin films were grown on GaAs (100) substrates by using molecular beam epitaxy at various temperatures. The results of the X-ray diffraction (XRD) patterns showed that the orientation of the grown CdTe thin films was the (100) orientation. XRD patterns, atomic force microscopy images, high-resolution transmission electron microscopy (HRTEM) images, and photoluminescence spectra showed that the crystallinity of CdTe (100) epilayers grown on GaAs (100) substrates was improved by increasing the substrate temperature. HRTEM images showed that misfit dislocations existed at the CdTe / GaAs heterointerface. These results can help improve understanding of the substrate temperature effect on the structural and the optical properties of CdTe (100)/ GaAs (100) heterostructures.

The reactive ion etching of Bi2Ti2O7 thin films on silicon substrates and its image in atomic force microscopy

2002 ◽  
Vol 235 (1-4) ◽  
pp. 411-414 ◽  
Author(s):  
Zhuo Wang ◽  
Daliang Sun ◽  
Jifan Hu ◽  
Deliang Cui ◽  
Xiaohong Xu ◽  
...  
Keyword(s):  
Thin Films ◽  
Atomic Force Microscopy ◽  
Reactive Ion Etching ◽  
Silicon Substrates ◽  
Ion Etching ◽  
Force Microscopy ◽  
Atomic Force

scholarly journals Effect the Composition Ratio of Cobalt Oxide on the Structural and Optical Properties of Tin Oxide

2019 ◽  
Vol 24 (3) ◽  
Author(s):  
Ahmed K. Abass, ◽  
Sura A. Abd Al-Hassan
Keyword(s):  
Thin Films ◽  
Optical Properties ◽  
Cobalt Oxide ◽  
Tin Oxide ◽  
Spray Pyrolysis Technique ◽  
Oxide Thin Film ◽  
Chemical Spray Pyrolysis ◽  
Force Microscopy ◽  
Atomic Force ◽  
Xrd Patterns

Tin oxide thin films were deposited on glass substrate at (400 ºC) by using chemical spray pyrolysis technique and its composed with cobalt oxide in different ratio. The structural, morphologic and optical properties of  thin films are investigated by: (XRD) X-Ray Diffraction, (AFM) Atomic Force Microscopy, (UV-Vis )Ultraviolet – Visible Spectroscopy. XRD patterns indicate that the structure of tin oxide thin film is tetragonal. All prepared films were nano materials as stated by Scherrer equation. It might have been found by AFM analysis, those surface roughness increase with increasing of cobalt ratio. By provision about Tauc plots, optical band gaps for thin                               

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