The relationship between refractive index-energy gap and the film thickness effect on the characteristic parameters of CdSe thin films

2011 ◽  
Vol 284 (9) ◽  
pp. 2307-2311 ◽  
Author(s):  
Yunus Akaltun ◽  
M. Ali Yıldırım ◽  
Aytunç Ateş ◽  
Muhammet Yıldırım
Keyword(s):  
Thin Films ◽  
Refractive Index ◽  
Film Thickness ◽  
Energy Gap ◽  
Thickness Effect ◽  
Characteristic Parameters ◽  
The Relationship

OPTICAL PROPERTIES OF THERMALLY EVAPORATED METAL-FREE PHTHALOCYANINE (H2Pc) THIN FILMS

2005 ◽  
Vol 19 (27) ◽  
pp. 4057-4071 ◽  
Author(s):  
M. M. EL-NAHASS ◽  
M. M. SALLAM ◽  
H. A. M. ALI
Keyword(s):  
Thin Films ◽  
Refractive Index ◽  
Optical Properties ◽  
Film Thickness ◽  
Energy Gap ◽  
Fundamental Absorption Edge ◽  
Absorption Region ◽  
Metal Free ◽  
Polycrystalline Form ◽  
Absorption Measurements

The optical properties of metal-free phtalocyanine ( H 2 Pc ) in thin film form is investigated. X-ray diffractograms of the ( H 2 Pc ) powder show that it has a α-polycrystalline form with a monoclinic structure. The thermal evaporation of ( H 2 Pc ) powder leads to α-polycrystalline films, oriented preferentially to the (001) plane. After annealing at 623 K for two hours, a mixture of α- and β-phases is formed on an amorphous background. The optical properties of ( H 2 Pc ) thin films have been studied using spectrophotometeric measurements of transmittance and reflectance in the range 200–2200 nm for a different film thickness. The refractive index and the absorption index show independence on the film thickness. The refractive index shows anomalous dispersion in the region of the fundamental absorption edge. The absorption measurements show the characteristic splitting of the Q-band and ΔQ is obtained as 0.22 eV. The absorption coefficient in the absorption region reveals indirect transitions. The fundamental and the onset energy gap are determined as 2.74 eV and 1.55 eV, respectively.

scholarly journals Low-Temperature Synthesis, Structural and Optical Characterizations of The Novel Bisbs3 Thin Films as Anew Absorber Layer for Solar Cells

2021 ◽  
Author(s):  
I M El radaf ◽  
H.Y.S Al-Zahrani
Keyword(s):  
Thin Films ◽  
Refractive Index ◽  
Film Thickness ◽  
Energy Gap ◽  
Structural Parameters ◽  
Research Work ◽  
Optical Parameters ◽  
Glass Substrates ◽  
Diffraction Patterns ◽  
P Type

Abstract In this research work, thin films of BiSbS3 have been successfully synthesized onto well cleaned soda-lima glass substrates via the chemical bath deposition procedure at different thicknesses (t= 159, 243, 296 and 362 nm). The X-ray diffraction patterns of the chemically deposited BiSbS3 films depicted that the synthesized films exposed polycrystalline nature and have an orthorhombic structure. The structural parameters of the chemically deposited BiSbS3 films were evaluated by Debye-Scherer’s formulas. The surface morphologies of the BiSbS3 films were fixed via the field-emission-scanning-electron microscope. The analyses of the linear optical parameters of the chemically deposited BiSbS3 thin films refer to improving the values of the absorption coefficient, α and the linear refractive index, n via the increase in the film thickness. In addition, there is an observed reduction in the energy gap, Eg values from 1.38 to 1.22 eV occurred by raising the film thickness. Furthermore, there is an enhancement in the nonlinear optical constants and the optoelectrical parameters occurred by raising the film thickness where the nonlinear refractive index, \({n}_{2},\)the optical free carrier concentration, \({N}_{opt}\) and the optical conductivity σopt were enlarged with increasing the values of film thickness. Moreover, the hot probe procedure was applied to the BiSbS3 thin films and this method demonstrated that the chemically deposited BiSbS3 films are p-type semiconductors.

Dependence of Film Thickness on Properties of Al Doped ZnO Thin Films

2011 ◽  
Vol 194-196 ◽  
pp. 2305-2311
Author(s):  
Ying Ge Yang ◽  
Dong Mei Zeng ◽  
Hai Zhou ◽  
Wen Ran Feng ◽  
Shan Lu ◽  
...  
Keyword(s):  
Thin Films ◽  
Film Thickness ◽  
Electrical Parameter ◽  
Substrate Surface ◽  
Rf Magnetron Sputtering ◽  
Thickness Effect ◽  
Visible Range ◽  
Glass Substrates ◽  
Doped Zno

In this study high quality of Al doped ZnO (ZAO) thin films were prepared by RF magnetron sputtering on glass substrates at room temperature in order to study the thickness effect upon their structure, electrical and optical properties. XRD results show that the films are polycrystalline and with strongly preferred (002) orientation perpendicular to substrate surface whatever the thickness is. The crystallite size was calculated by Williamson-Hall method, while it increases as the film thickness increased. The lattice stress is mainly caused by the growth process. Hall measurements revealed electrical parameter very dependent upon thickness when the thickness of ZAO film is lower than 700 nm. The resistivity decreased and the carrier concentration and Hall mobility increases as the film thickness increased. When film thickness becomes larger, only a little change in the above properties was observed. All the films have high transmittance above 90% in visible range. Red shift of the absorption edge was observed as thickness increased. The optical energy bandgap decreased from 3.41eV to 3.30 eV with the increase of film thickness.

Film thickness effect on texture and residual stress sign transition in sputtered TiN thin films

2017 ◽  
Vol 43 (15) ◽  
pp. 11992-11997 ◽  
Author(s):  
Yeting Xi ◽  
Kewei Gao ◽  
Xiaolu Pang ◽  
Huisheng Yang ◽  
Xiaotao Xiong ◽  
...  
Keyword(s):  
Thin Films ◽  
Residual Stress ◽  
Film Thickness ◽  
Thickness Effect ◽  
Tin Thin Films

Investigation of Optical Properties of Aluminium Doped Zinc Oxide Thin Films Deposited by Magnetron Sputtering

2013 ◽  
Vol 446-447 ◽  
pp. 259-262
Author(s):  
J.H. Gu ◽  
T. Zhang ◽  
Z.Y. Zhong ◽  
C.Y. Yang ◽  
J. Hou
Keyword(s):  
Thin Films ◽  
Zinc Oxide ◽  
Refractive Index ◽  
Magnetron Sputtering ◽  
Structural Properties ◽  
Energy Gap ◽  
Dispersion Model ◽  
Argon Pressure ◽  
Optical Energy Gap ◽  
Characterization Methods

Aluminium doped zinc oxide (AZO) thin films were prepared by magnetron-sputtering. The optical and structural properties of the films were investigated by optical transmission spectra and X-ray diffraction (XRD) measurements, respectively. The results indicate that the AZO films have hexagonal wurtzite structure with highly c-axis preferred orientation. The optical and structural properties of the films are observed to be subjected to the argon pressure. The AZO film prepared at the argon pressure of 0.5 Pa exhibits the largest crystallite size and the highest average visible transmittance. Also, the refractive index and optical energy-gap of the films were determined by optical characterization methods. The dispersion behavior of the refractive index was studied using the Sellmeier’s dispersion model.

The Influence of Bi Content on the Properties of Bismuth Ferrite Thin Films Fabricated by Magnetron Sputtering

2013 ◽  
Vol 745-746 ◽  
pp. 131-135
Author(s):  
Hu Rui Yan ◽  
Nuo Fan Ding ◽  
Gang Wu ◽  
Ping Xiong Yang ◽  
Jun Hao Chu ◽  
...  
Keyword(s):  
Thin Films ◽  
Refractive Index ◽  
Magnetron Sputtering ◽  
Extinction Coefficient ◽  
Energy Gap ◽  
Lattice Mismatch ◽  
Bismuth Ferrite ◽  
Film Surface ◽  
Si Substrate ◽  
Impurity Phases

In the process of BiFeO3 film preparation by magnetron sputtering, Bi element is volatile, leading to the films which often appear impurity phases. Therefore, Both Bi excessive 5% (B1.05FO) and 8% (B1.08FO) BFO film in Si substrate were prepared by magnetron sputtering. X-Ray Diffraction (XRD) results showed that the BFO thin films fabricated in the Si substrate are perovskite structure, that the B1.08FO film appeared less impurity phases than B1.05FO film, and that stress due to substrate lattice mismatch caused the shift of XRD patterns. In Raman study, it was concluded that both B1.08FO film and B1.05FO film appeared ten Raman peaks in the range from 50cm-1 to 800cm-1, and that B1.08FO Raman peaks intensity was stronger in 137.1cm-1.168.5cm-1 and 215.3cm-1. Spectroscopic ellipsometry test showed that the refractive index and the extinction coefficient of B1.05FO film were 2.25 and 0.07 respectively in 600 nm with 2.67eV of energy gap; the refractive index and the extinction coefficient of B1.08FO film were 2.14 and 0.05 in 600 nm respectively with 2.71eV of energy gap. Atomic Force Microscope (AFM) was used to characterize the film surface morphology, finding that the B1.08FO film prepared in Si substrate was denser while grain size and surface roughness were smaller.

Film Thickness Effect on Tensile Properties and Microstructures of Submicron Aluminum Thin Films on Polyimide

1996 ◽  
Vol 436 ◽  
Author(s):  
Y. S. Kang ◽  
P. S. Ho ◽  
R. Knipe ◽  
J. Tregilgas
Keyword(s):  
Thin Films ◽  
Grain Size ◽  
Film Thickness ◽  
Metal Film ◽  
Tensile Force ◽  
Thickness Effect ◽  
Published Data ◽  
Free Standing ◽  
Aluminum Films ◽  
Flexible Polymer

AbstractThe mechanical behavior of the metal film on a polymer substrate becomes an important issue in microelectronics metallization. The metal/polymer structure is also useful to investigate the deformation behavior of very thin free-standing metal film since the flexible polymer serves as a deformable substrate. The tensile force-elongation curves have been measured using a microtensile tester for aluminum thin films, deposited on a PMDA-ODA polyimide film, in the thickness range from 60 rum to 480 nm. The stress-strain curves for aluminum films were constructed by subtracting these curves with polyimide curves measured separately. Tensile strength increases linearly with decreasing film thickness from 196 MPa to 408 MPa within the film thickness range studied. This is in good agreement with the published data for free-standing aluminum films in the same thickness range. The measured Young's modulus is lower than the bulk modulus and exhibits no systematic dependence on the film thickness. The microstructures of aluminum films have been examined using a transmission electron microscope (TEM). These films posses the (111)-textured columnar grain structures. Grain sizes exhibit log-normal distributions and the mean grain size increases monotonically with the film thickness. An attempt is made to evaluate the effect of film thickness and grain size on the strength of aluminum thin film and the result is discussed.

Effect of Film Thickness on the Rheological Properties of Asphalts in Contact with Aggregate Surface

1998 ◽  
Vol 1638 (1) ◽  
pp. 31-39 ◽  
Author(s):  
Shin-Che Huang ◽  
Jan F. Branthaver ◽  
Raymond E. Robertson ◽  
Sang-Soo Kim
Keyword(s):  
Thin Films ◽  
Film Thickness ◽  
Rheological Properties ◽  
Thickness Effect ◽  
Asphalt Binders ◽  
Shear Rates ◽  
Service Environment ◽  
Asphalt Mix ◽  
Plate Geometry ◽  
Low Shear

The effect of the interaction between aggregate and asphalt on asphalt mix properties has been a subject of many studies. However, studies using compacted mixtures cannot isolate the pure effects of the asphalt-aggregate interactions, while studies using mixtures of asphalt and fines cannot determine the asphalt rheology at the interface. In this study, direct measurement of asphalt rheology at the interface is investigated using the sliding plate geometry with machined aggregate plates. Significant differences in the behavior of asphalts in contact with aggregate plates have been observed, especially at low shear rates. One asphalt shows substantial aggregate surface-induced structuring, while another asphalt shows essentially none. In addition, the film thickness effect on the rheological properties of asphalt binders and asphalt aggregate mixtures was investigated. The results strongly show that thin films of asphalt on an aggregate surface have substantially changed rheological properties that are asphalt composition–dependent, and that asphalts that are graded alike as bulk materials do not have the same rheological properties as thin films, in this service environment.

scholarly journals Synthesis and characterization of Eu3+ doped TiO2 thin films deposited by spray pyrolysis technique for photocatalytic application

2020 ◽  
Author(s):  
Shereen Alshomar
Keyword(s):  
Thin Films ◽  
Methylene Blue ◽  
Refractive Index ◽  
Optical Properties ◽  
Film Thickness ◽  
Photocatalytic Degradation ◽  
Spray Pyrolysis ◽  
Spray Pyrolysis Technique ◽  
Average Grain Size ◽  
Double Beam

Abstract In this study, nanocrystalline TiO 2 : Eu 3+ thin films are successfully formed by spray pyrolysis technique deposited on glass substrate. Optical, electrical, structure, surface morphology, and photocatalytic degradation of Methylene blue have been examined. The optical properties of the films are analyzed using transmittance and reflectance spectra, which are measured using UV-Vis-NIR double-beam spectrophotometer. Optical properties such as refractive index (n), extinction coefficient (k), optical conductivity (σ) and Urbach energy (E u ) have been calculated as a function of Eu 3+ concentration. Film thickness were evaluated using the refractive index dependence on wavelength . The films thickness were determined as 97.13, 122.62, 123.24, 117.14 and 128.25 nm, respectively, for Eu doped TiO 2 at 0,4, 6, 8 and 10 wt % doping concentration. The band gap values raised from 3.29 to 3.42 eV with increasing the Eu 3+ dopant concentration. The highest electrical conductivity was found to be 3.01x10 -2 (Ω.cm) -1 at high doping level with 10 wt% Eu 3+ . The XRD analysis illustrate the tetragonal crystal structure of films with anatase phase and reduces crystallite size linearly with increasing Eu 3+ concentration. Scanning electron microscopy (SEM) analysis indicated consistent allocation of irregular and spherical shaped grains covering the substrate surface. The average grain size in range of 82.5 – 51.1 nm is observed and films show porous nature. The photocatalytic effect of TiO 2 : Eu 3+ thin films is predicted from the degradation of methylene blue (MB) at room temperature under UV light irradiation. An enhancement in photocatalytic degradation observed by increasing the amount of Eu 3+ due to increase in the e/h pair production and increase of film thickness. These results make TiO 2 : Eu 3+ thin films as attractive candidate for photovoltaic cells and other optoelectronic device applications

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