scholarly journals Influence of Film Thickness and Heat Treatment on the Physical Properties of Mn Doped Sb2Se3 Nanocrystalline Thin Films

2017 ◽  
Vol 2017 ◽  
pp. 1-14 ◽  
Author(s):  
I. K. El Zawawi ◽  
Manal A. Mahdy ◽  
E. A. El-Sayad
Keyword(s):  
Thin Films ◽  
Heat Treatment ◽  
Film Thickness ◽  
Energy Gap ◽  
Blue Shift ◽  
Amorphous Structure ◽  
Treatment Temperature ◽  
Optical Energy Gap ◽  
Heat Treated ◽  
Nanocrystalline Thin Films

Nanocrystalline thin films of Sb37.07Mn1.95Se60.98 with different thickness (7, 20, 40, and 80 nm) were successfully prepared via inert gas condensation technique. As-deposited films showed amorphous structure by grazing incident in-plane X-ray diffraction (GIIXD) technique. All films of different thicknesses were heat treated at 433 K for 90 min. The GIIXD pattern of annealed films showed nanocrystalline orthorhombic structure. The effect of thickness of annealed films on the structure and optical properties was studied. Calculated particle sizes are 20.67 and 24.15 for 40 and 80 nm thickness of heat treated film. High resolution transmission electron microscope HRTEM images and their diffraction patterns proved that 40 nm film thickness annealed at different temperature has nanocrystalline nature with observed (high) crystallinity that increases with annealing temperature. Blue shift of optical energy gap was observed from 1.68 to 2 eV with decreasing film thickness from 80 to 7 nm. Film thickness of 40 nm was exposed to different heat treated temperatures from 353 to 473 K to detect its effect on structure and optical and electrical properties. Blue shift from 1.73 to 1.9 eV was observed in its optical band gap due to direct transition as heat treatment temperature decreasing from 473 to 353 K. Electrical conductivity was studied for different heat treated films of thickness 40 nm, and intrinsic conduction mechanism is dominant. The activation energy Ea was affected by heat treatment process.

scholarly journals Optical Investigations of CdSe1-x Tex Thin Films

2011 ◽  
Vol 8 (1) ◽  
pp. 123-133 ◽  
Author(s):  
Baghdad Science Journal
Keyword(s):  
Thin Films ◽  
Heat Treatment ◽  
Energy Gap ◽  
Fundamental Absorption Edge ◽  
Low Pressure ◽  
Direct Transition ◽  
Optical Energy Gap ◽  
Thermal Evaporation Method ◽  
Glass Substrates ◽  
Heat Treated

The alloys of CdSe1-xTex compound have been prepared from their elements successfully with high purity (99.9999%) which mixed stoichiometry ratio (x=0.0, 0.25, 0.5, 0.75 and 1.0) of (Cd, Se and Te) elements. Films of CdSe1-xTex alloys for different values of composition with thickness(0.5?m) have been prepared by thermal evaporation method at cleaned glass substrates which heated at (473K) under very low pressure (4×10-5mbar) at rate of deposition (3A?/s), after that thin films have been heat treated under low pressure (10-2mbar) at (523K) for two hours. The optical studies revealed that the absorption coefficient (?) is fairly high. It is found that the electronic transitions in the fundamental absorption edge tend to be allowed direct transition. It was also found that the optical energy gap vary non-linearly with composition (x) and have a minimum value at x=0.5 and increases after heat treatment. It is found that the optical constants vary non-linearly with composition, and the behavior inverse at x=0.5, and affected by heat treatment. The behavior of ?1 is similar to the behavior of n, while the behavior of ?2 is similar to the behavior of k.

scholarly journals Hydrogenated Nano-Crystalline Silicon Thin Films in SiO2 Matrix for Next Generation Solar Cells Using Glow Discharged Decomposition

2018 ◽  
Vol 8 (1) ◽  
pp. 25
Author(s):  
Moniruzzaman Syed ◽  
Cameron Hynes ◽  
Brittany Anderson ◽  
Temer S Ahmadi ◽  
Boon Tong Goh ◽  
...  
Keyword(s):  
Thin Films ◽  
Substrate Temperature ◽  
Energy Gap ◽  
Volume Fraction ◽  
Crystalline Silicon ◽  
Strong Dependence ◽  
Blue Shift ◽  
Nanocrystalline Silicon ◽  
Optical Energy Gap ◽  
Substrate Temperatures

Hydrogenated Nanocrystalline Silicon (nc-Si:H) thin films using SiH4/H2 mixture by glow discharged decomposition were investigated on c-Si and glass substrates. The effects of substrate temperature on the Structural, Optical and Electrical properties of the films were investigated by X-ray diffraction, Raman scattering, FT/IR, Optical transmission and Atomic Force Microscopy (AFM). Substrate temperatures ([TSB]) of the films were changed from 100oC to 250oC. It has been revealed the strong dependence on the film’s properties with the substrate temperatures. XRD and Raman measurements were shown that the higher substrate temperature (250oC) exhibits the highest crystalline volume fraction ([ρ] = 95%) and the lowest crystalline size ([Ω] = 3.5 nm) as well, having the highest H-content and the lowest O-content. At 250oC, the lowest mobility and the highest resistivity were also found to be ~37.5 cm2/v.s and 7.35 Ω-cm. Refractive index and the optical energy gap (Eg) were estimated by 3.8 and 1.9 eV having the growth rate of 4.2 nm/min. At 250oC, it was resulted in a blue shift of the absorption edge having uniform grain distributions. Results indicate that in situ hydrogen cleaning effects is prominent and localized orderly high density Si-Si bonds are exhibiting quantum size effects at highest substrate temperature.

Structural, Optical, and Optoelectrical Studies of Spray Pyrolyzed CuGaSnS4 Thin Films

2021 ◽  
Author(s):  
Islam M El radaf ◽  
Hnan Y Alzahrani
Keyword(s):  
Thin Films ◽  
Film Thickness ◽  
Nonlinear Optical ◽  
Energy Gap ◽  
Structural Parameters ◽  
Stoichiometric Composition ◽  
Optical Energy Gap ◽  
Linear Absorption ◽  
Glass Substrates ◽  
D Values

Abstract We deposited CuGaSnS4 thin films on soda-lima glass substrates via a spray pyrolysis process. The X-ray diffraction of CuGaSnS4 films established the formation of an orthorhombic single phase. In addition, the structural parameters of the CuGaSnS4 films were estimated by Debye-Scherer’s formulas, which showed that an enhancement in crystallite size (D) values occurred by increasing the thickness of the investigated films. The EDAX pattern of CuGaSnS4 films confirms a stoichiometric composition. The optical results revealed that the CuGaSnS4 films possessed a direct optical energy gap (Eg). The Eg values were reduced from 1.50 to 1.38 eV with the increase in thickness. Also, there was an observed increase in the linear refractive index and the linear absorption coefficient values occurred due to the increased thickness. Finally, the optoelectrical constants of the sprayed CuGaSnS4 films such as the optical conductivity (σopt) and the optical free carrier concentration to effective mass (N_opt/m^* ) were enlarged with increasing film thickness. The nonlinear optical study showed that the increase in film thickness enhanced the nonlinear optical constants of CuGaSnS4 films. The hot-probe procedure shows that the sprayed CuGaSnS4 films expose p-type conductivity.

Morphology of Carbon Micro-Coils

2004 ◽  
Vol 449-452 ◽  
pp. 205-208
Author(s):  
M. Fujii ◽  
S. Motojima
Keyword(s):  
Heat Treatment ◽  
Lattice Structure ◽  
Diffraction Method ◽  
Chemical Vapor ◽  
Amorphous Structure ◽  
Treatment Temperature ◽  
X Ray Diffraction ◽  
X Ray ◽  
Heat Treated ◽  
Higher Temperature

The double helical carbon micro-coils were obtained by chemical vapor deposition. As-grown carbon micro-coils with amorphous structure were heat-treated at various temperatures up to 3000°C . By heat treatment, the shape of the coils was not changed. The morphology of these coils was observed in detail using electron microscope. The lattice structure was analyzed by X-ray diffraction method. Heat treatment temperature dependence of the magnetoresistance and the measurement of Raman spectra suggest that the coils heattreated at higher temperature are more highly graphitized.

scholarly journals Effect of thickness on the optical properties of ZnO thin films prepared by pulsed laser deposition technique (PLD)

2019 ◽  
Vol 15 (32) ◽  
pp. 114-121
Author(s):  
Maysar A. Salim
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Optical Properties ◽  
Film Thickness ◽  
Energy Gap ◽  
Transparent Conducting Oxide ◽  
Zno Thin Films ◽  
Zno Films ◽  
Zno Thin Film ◽  
Optical Energy Gap

Zinc Oxide (ZnO) thin films of different thickness were preparedon ultrasonically cleaned corning glass substrate, by pulsed laserdeposition technique (PLD) at room temperature. Since mostapplication of ZnO thin film are certainly related to its opticalproperties, so the optical properties of ZnO thin film in thewavelength range (300-1100) nm were studied, it was observed thatall ZnO films have high transmittance (˃ 80 %) in the wavelengthregion (400-1100) nm and it increase as the film thickness increase,using the optical transmittance to calculate optical energy gap (Egopt)show that (Egopt) of a direct allowed transition and its value nearlyconstant (~ 3.2 eV) for all film thickness (150, 180, 210, and 240)nm, so Zn0 thin films were used as a transparent conducting oxide(TCO) in various optoelectronic application such as a window in athin film solar cells.

Effect of Heat Treatment on Microstructure and Corrosion Resistance of Ni-P/BN(h) Composite Coatings

2011 ◽  
Vol 239-242 ◽  
pp. 3362-3366
Author(s):  
Cheng Zhang Peng ◽  
Ling Ling Zhu ◽  
You Ming Chen
Keyword(s):  
Heat Treatment ◽  
Corrosion Resistance ◽  
Composite Coatings ◽  
Stable State ◽  
Amorphous Structure ◽  
Treatment Temperature ◽  
X Ray Diffraction ◽  
Pulse Electroplating ◽  
Heat Treated ◽  
Precipitated Phases

The Ni-P/ BN(h) composite coatings were prepared by pulse electroplating,and were heat treated at temperature of 200～400°C.The microstructure of the composite coatings was identified by X-ray diffraction,the corrosion behavior of the composite coatings in 3.5%NaCl and 10%H2SO4 solutions was investigated by the linear polarization measurements and scanning electron microscope (SEM).The results show that the as-deposited is an amorphous structure,the precipitated phases are Ni12P5 and Ni5P2 metastable state phases when heat treatment temperature is below 300°C,the precipitated phases is Ni3P stable state phase heat-treated at 400°C，the composite coating was crystallized in great degree.Both the as-deposited and heat treated composite coatings revealed best corrosion resistance in 3.5%NaCl and 10%H2SO4 solutions.

scholarly journals Annealing effect on the optical properties of organic semiconductor Alq3: C60 blend thin films

2019 ◽  
Vol 16 (39) ◽  
pp. 1-10
Author(s):  
Lamiaa K. Abbas
Keyword(s):  
Thin Films ◽  
Optical Properties ◽  
Annealing Temperature ◽  
Energy Gap ◽  
Bulk Heterojunction ◽  
Chemical Bonds ◽  
Optical Energy Gap ◽  
Heat Treated ◽  
Infra Red ◽  
Uv Visible

The effect of heat treatment using different annealing temperatures on optical properties of bulk heterojunction blend (BHJ) Alq3: C60 thin films which are fabricated by the spin coating technique were investigated in this study. The films have been coated on a glass substrate with speed of 2000 rpm for one min and treated with different annealing temperature (373, 423 and 473) K under vacuum. The optical properties and the chemical bonds structure of blends as-deposited and heat treated have been studied by UV-Vis spectroscopic and Fourier Transform-Infra Red (FTIR) measurements respectively. The results of UV visible show that the optical energy gap decreasing with increasing the annealing temperature for the ratio (100:1) while decreasing with increasing the annealing temperature for ratio (100:10). The FTIR spectra measurement were applied to know the type of the bonds of Alq3: C60 BHJ thin films.

scholarly journals Structural and optical properties of tungsten doped TiO2 thin films fabricated by spray pyrolysis technique

2020 ◽  
Vol 2 (1) ◽  
pp. 1-8
Author(s):  
Tamilnayagam V ◽  
Keerthika Kumarasamy ◽  
Tamiloli Devendhiran ◽  
Mohanraj K ◽  
Ilavarasan L
Keyword(s):  
Thin Films ◽  
Spray Pyrolysis ◽  
Energy Gap ◽  
Spray Pyrolysis Technique ◽  
Amorphous Structure ◽  
Tio2 Thin Films ◽  
Optical Energy Gap ◽  
Force Microscopy ◽  
Atomic Force ◽  
Double Beam

The pure and tungsten doped titanium oxide WxTi1-xO2 (x=0, 0.1) thin films have been successfully deposited on the glass substrate at 400 °C using spray pyrolysis technique. The structural properties of the prepared films were characterized by X-Ray Diffraction (XRD). From the XRD spectrum, the sample shows the amorphous structure. Their surface morphology was probed using Scanning Electron Microscopy (SEM) and the mechanical properties, topography and surface roughness of the grown films was investigated by Atomic Force Microscopy (AFM). The functional group and optical characteristic of prepared films were analyzed by Fourier Transform Infra-Red (FT-IR) spectroscopy and UV-Vis-double beam spectrometer.  The optical energy gap was determined by transmittance measurement.

ON THE OPTICAL CHARACTERISTICS OF CdS THIN FILMS DEPOSITED BY QUASI-CLOSED VOLUME TECHNIQUE

2004 ◽  
Vol 18 (09) ◽  
pp. 1287-1297 ◽  
Author(s):  
MIHAELA RUSU ◽  
IULIA SALAORU ◽  
M. E. POPA ◽  
G. I. RUSU
Keyword(s):  
Thin Films ◽  
Heat Treatment ◽  
Electrical Conductivity ◽  
Temperature Dependence ◽  
Absorption Spectra ◽  
Energy Gap ◽  
Index Of Refraction ◽  
Closed Volume ◽  
Optical Energy Gap ◽  
Cds Thin Films

Cadmium sulfide (CdS) thin films (d=0.15–1.15 μ m ) were deposited onto glass substrates by the quasi-closed volume technique under vacuum. The investigations shown that the films are polycrystalline and have a hexagonal structure. It was experimentally established that the films with stable structure can be obtained if they are submitted to a heat treatment, consisting of several succesive heating/cooling cycles within a given temperature range (ΔT=300–600 K ), the temperature dependence of the electrical conductivity becomes reversible. For heat-treated samples, the values of thermal activation energy calculated from the temperature dependence of the electrical conductivity, ranged between 2.30–2.45 eV. The spectral dependences of the transmission and absorption coefficients were studied in the range 500–1400 nm. The influence of heat treatment on the shape of the absorption spectra and dispersion index of refraction is studied for samples with different thickness. Optical energy gap, calculated from the absorption spectra was in the range 2.30–2.5 eV.

scholarly journals Emergence and Evolution of Crystallization in TiO2 Thin Films: A Structural and Morphological Study

Nanomaterials ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1409
Author(s):  
Ofelia Durante ◽  
Cinzia Di Giorgio ◽  
Veronica Granata ◽  
Joshua Neilson ◽  
Rosalba Fittipaldi ◽  
...  
Keyword(s):  
Thin Films ◽  
Film Thickness ◽  
Transition Metal Oxides ◽  
Annealing Temperature ◽  
Morphological Properties ◽  
Degree Of Crystallinity ◽  
Tio2 Thin Films ◽  
Force Microscopy ◽  
Heat Treated ◽  
Complementary Techniques

Among all transition metal oxides, titanium dioxide (TiO2) is one of the most intensively investigated materials due to its large range of applications, both in the amorphous and crystalline forms. We have produced amorphous TiO2 thin films by means of room temperature ion-plasma assisted e-beam deposition, and we have heat-treated the samples to study the onset of crystallization. Herein, we have detailed the earliest stage and the evolution of crystallization, as a function of both the annealing temperature, in the range 250–1000 °C, and the TiO2 thickness, varying between 5 and 200 nm. We have explored the structural and morphological properties of the as grown and heat-treated samples with Atomic Force Microscopy, Scanning Electron Microscopy, X-ray Diffractometry, and Raman spectroscopy. We have observed an increasing crystallization onset temperature as the film thickness is reduced, as well as remarkable differences in the crystallization evolution, depending on the film thickness. Moreover, we have shown a strong cross-talking among the complementary techniques used displaying that also surface imaging can provide distinctive information on material crystallization. Finally, we have also explored the phonon lifetime as a function of the TiO2 thickness and annealing temperature, both ultimately affecting the degree of crystallinity.

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