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.

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.

Effects of Annealing on Pulsed Laser Deposited TiO2 Thin Films

2013 ◽  
Vol 446-447 ◽  
pp. 306-311 ◽  
Author(s):  
Sudhanshu Dwivedi ◽  
Somnath Biswas
Keyword(s):  
Thin Films ◽  
Pulsed Laser ◽  
X Ray Diffraction ◽  
Force Microscopy ◽  
Si Substrates ◽  
Morphological Studies ◽  
Atomic Force ◽  
Deposited Films ◽  
Type Crystal

Mixed phase TiO2 thin films of rutile and anatase type crystal orientations were deposited on Si substrates by pulsed laser deposition (PLD) technique. When annealed at 800°C at 1 mbar oxygen pressure for 3 h, the deposited films transform into a single phase of rutile type. Structural and morphological studies of the as-deposited and annealed films were performed with X-ray diffraction (XRD), Fourier transform infra-red spectroscopy (FTIR), Raman spectroscopy, and atomic force microscopy (AFM). Photoluminescence (PL) spectroscopy was used for optical characterization of the annealed thin films.

FABRICATION OF CARBON THIN FILMS BY PULSED LASER DEPOSITION IN DIFFERENT AMBIENT ENVIRONMENTS

2016 ◽  
Vol 78 (3) ◽  
Author(s):  
Mohamad Helmi Abd Mubin ◽  
Muhammad Sufi Roslan ◽  
Syed Zuhaib Haider Rizvi ◽  
Kashif Chaudhary ◽  
Suzairi Daud ◽  
...  
Keyword(s):  
Thin Films ◽  
Peak Height ◽  
Maximum Height ◽  
Ambient Conditions ◽  
Graphite Target ◽  
Force Microscopy ◽  
Atomic Force ◽  
Average Maximum ◽  
Spacing Ratio ◽  
Carbon Thin Films

In this work, carbon thin films are grown in different background environments (Air, Helium and Argon) at different pressures (60, 160, 500 and 1000 mbar) by ablating the graphite target with Nd:YAG laser of wavelength of 1064 nm, pulse energy of 740 mJ and pulse rate of 6 ns. 10,000 laser shots are used to ablate graphite target under different ambient conditions. Grown thin films are analyzed by Atomic Force Microscopy (AFM) to measure thickness, roughness average, maximum profile peak height, average maximum height of profile and spacing ratio of the surface. The obtained results show that the roughness average, thickness of film, maximum profile peak height, average maximum height of profile and spacing ratio of thin films decreases with increase in ambient pressuresand shows highest value at low pressure (160 mbar) in helium environment as compared with air and argon.

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.

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

Self Organization in Thin Films of a Substituted Perylene Imide with a Twisted Aromatic Core

2006 ◽  
Vol 965 ◽  
Author(s):  
Harald Graaf ◽  
Christine C Mattheus ◽  
Derck Schlettwein
Keyword(s):  
Thin Films ◽  
Physical Vapor Deposition ◽  
Solid Phase ◽  
Amorphous Solid ◽  
Optical Methods ◽  
Ambient Conditions ◽  
Force Microscopy ◽  
Atomic Force ◽  
Molecular Semiconductor ◽  
Perylene Bisimides

ABSTRACTThe aromatic core of perylene bisimides can be twisted by chemical substitution with chlorine in the bay-position. An example for this strategy is 1,6,7,10-tetra-chloro-N,N'-dimethyl-perylene-tetracarboxylic-bisimide, Cl4MePTCDI. This twisting leads to a decrease in directed intermolecular interactions, which causes a decrease in the electronic coupling of the molecules, interesting to be investigated in thin films of this molecular semiconductor. An amorphous solid phase was formed by physical vapor deposition. This amorphous phase showed the tendency to crystallize under ambient conditions as apparent von optical microscopy at the films. The crystallized phase was investigated by atomic force microscopy AFM and optical methods, where a formation of weak excimers was found.

scholarly journals Surface and Optical Properties of Gd-Doped ZrO2 Nano Films

2020 ◽  
Vol 4 (1) ◽  
pp. 4
Author(s):  
Ognian Dimitrov ◽  
Irina Stambolova ◽  
Sasho Vassilev ◽  
Katerina Lazarova ◽  
Silvia Simeonova
Keyword(s):  
Thin Films ◽  
Rare Earth ◽  
Sol Gel ◽  
Earth Metal ◽  
Silicon Substrates ◽  
X Ray Diffraction ◽  
Average Roughness ◽  
Force Microscopy ◽  
Atomic Force ◽  
Skin Conditions

Nanosized coatings of ZrO2 were deposited on silicon substrates using sol-gel and spin coating techniques. The precursor solutions were prepared from ZrOCl2.8H2O with the addition of different percentage (0.5–5%) of rare earth Gd3+ ions as dopant. The thin films were homogeneous, with average thickness of 115 nm and refractive index (n) of 1.83. The X-ray diffraction analysis (XRD) revealed the presence of a varying mixture of monoclinic and tetragonal ZrO2 polycrystalline phases, depending on the dopant, all of which with nanosized crystallites. Scanning electron microscopy (SEM) as well as atomic force microscopy (AFM) methods were deployed to investigate the surface morphology and roughness of the thin films, respectively. They revealed a smooth, well uniform and crack-free surface with average roughness of 0.8 nm. It was established that the dopant concentration affects the photoluminescence (PL) properties of the samples. The undoped films exhibited broad violet-blue PL emission, while the addition of Gd3+ ions resulted in new narrow bands in both UV-B and visible light regions, characteristic of the rare earth metal. The intensive emission located at 313 nm can find useful application in medical lamps for treatment of different skin conditions.

Shape Memory Property Alteration of Amorphous NiTi Thin Films Through Aging Heat Treatment

2009 ◽  
Author(s):  
Gen Satoh ◽  
Andrew Birnbaum ◽  
Y. Lawrence Yao
Keyword(s):  
Thin Films ◽  
Heat Treatment ◽  
Shape Memory ◽  
Treatment Time ◽  
Dissipated Energy ◽  
Silicon Substrates ◽  
Transformation Temperatures ◽  
Force Microscopy ◽  
Atomic Force ◽  
Shape Memory Properties

Thin film shape memory alloys have recently become a promising material for actuation of devices on the micro scale such as micro-pumps and micro-valves. Their utilization, however, has been limited due to the difficulty in tailoring their properties for different applications. Control over the transformation temperatures as well as mechanical and shape memory properties is required to enable their widespread use. This study examines the effects of heat treatment time and temperature on the properties of amorphous, Ti-rich NiTi thin films on silicon substrates. The effects on the transformation temperatures are investigated through the use of temperature dependent optical microscopy. The modulus and hardness, as well as dissipated energy and depth recovery are obtained through nano-indentation and atomic force microscopy (AFM). The role of microstructure and composition in altering both the mechanical and shape memory properties of the films is discussed.

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