Envelope Method Applied on the AZO Thin Films

2012 ◽  
Vol 268-270 ◽  
pp. 202-206
Author(s):  
Ying Xu ◽  
Peng Hua Ma ◽  
Mo Ning Liu
Keyword(s):  
Thin Films ◽  
Refractive Index ◽  
Film Thickness ◽  
Optical Constants ◽  
Light Transmittance ◽  
Incident Wavelength ◽  
Weak Absorption ◽  
Transmittance Spectra ◽  
Glass Substrates ◽  
Envelope Method

The AZO thin films had been prepared on glass substrates by APCVD process .The transmittance spectra of AZO thin films was measured with S-600 UV-Vis spectrophotometer . The visible light transmittance values of AZO thin films are about 85% and the thickness of the thin films well-distributed by the transmittance spectra of AZO films. Using the envelope method, the film thickness d is calculated about 964.43nm and the discrepancy is only 0.56% compared with the result of instrument measurements. The curve about the refractive index n with the incident wavelength is consistent with the reported literature results. The envelope method is suitable for the optical constants processing of some similar AZO films where exist weak absorption ranges (T≥0.4).

A NOVEL METHOD FOR PRODUCING NANOSTRUCTURED CdSe THIN FILM

2019 ◽  
Vol 27 (07) ◽  
pp. 1950175 ◽  
Author(s):  
İSHAK AFŞIN KARİPER
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Refractive Index ◽  
Film Thickness ◽  
Sem Analysis ◽  
Optical Bandgap ◽  
Cdse Thin Film ◽  
Glass Substrates ◽  
Commercial Glass ◽  
Ph Level

In this study, we produced Cadmium selenide (CdSe) crystalline thin film on commercial glass substrates via chemical bath deposition. Transmittance, absorbance, refractive index and optical bandgap of thin films were examined by UV/vis spectrum. XRD revealed a hexagonal form. The pH level of the baths in which CdSe thin films were deposited varied and optical and structural properties of the resulting thin films were analyzed. SEM analysis was used for surface analysis. Some features of the films were supposed to change with pH and these properties were investigated by testing different pH levels, which were 8, 9, 10 and 11. The variation of the optical bandgap changed between 1.60 and 1.75[Formula: see text]eV, according to the pH of deposition bath. Film thickness varied from 60[Formula: see text]nm to 93[Formula: see text]nm, with the variation of deposition bath’s pH. Moreover, it has been found that refractive index values were also changed with film thickness; these were calculated as 2.28, 2.19, 2.22 and 2.36 for 93.27, 60.97, 61.09 and 60.18[Formula: see text]nm, respectively. Dielectric constant also varied with refractive index, taking values 0.85, 0.75, 0.78, 0.93 for refractive indexes 2.28, 2.19, 2.22 and 2.36, respectively.

scholarly journals Further Increasing the Accuracy of Characterization of a Thin Dielectric or Semiconductor Film on a Substrate from Its Interference Transmittance Spectrum

Materials ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4681
Author(s):  
Dorian Minkov ◽  
Emilio Marquez ◽  
George Angelov ◽  
Gavril Gavrilov ◽  
Susana Ruano ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Refractive Index ◽  
Film Thickness ◽  
High Accuracy ◽  
Transmittance Spectrum ◽  
Semiconductor Film ◽  
Envelope Method ◽  
Average Film Thickness

Three means are investigated for further increasing the accuracy of the characterization of a thin film on a substrate, from the transmittance spectrum T(λ) of the specimen, based on the envelope method. Firstly, it is demonstrated that the accuracy of characterization, of the average film thickness d¯ and the thickness non-uniformity ∆d over the illuminated area, increases, employing a simple dual transformation utilizing the product T(λ)xs(λ), where Tsm(λ) is the smoothed spectrum of T(λ) and xs(λ) is the substrate absorbance. Secondly, an approach is proposed for selecting an interval of wavelengths, so that using envelope points only from this interval provides the most accurate characterization of d¯ and ∆d, as this approach is applicable no matter whether the substrate is transparent or non-transparent. Thirdly, the refractive index n(λ) and the extinction coefficient k(λ) are computed, employing curve fitting by polynomials of the optimized degree of 1/λ, instead of by previously used either polynomial of the optimized degree of λ or a two-term exponential of λ. An algorithm is developed, applying these three means, and implemented, to characterize a-Si and As98Te2 thin films. Record high accuracy within 0.1% is achieved in the computation of d¯ and n(λ) of these films.

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.

scholarly journals Optical constants of sputtered beryllium thin films determined from photoabsorption measurements in the spectral range 20.4–250 eV

2020 ◽  
Vol 27 (1) ◽  
pp. 75-82
Author(s):  
Mikhail Svechnikov ◽  
Nikolay Chkhalo ◽  
Alexey Lopatin ◽  
Roman Pleshkov ◽  
Vladimir Polkovnikov ◽  
...  
Keyword(s):  
Thin Films ◽  
Refractive Index ◽  
Synchrotron Radiation ◽  
Initial Data ◽  
Absorption Coefficient ◽  
Energy Range ◽  
Transmission Coefficient ◽  
Radiation Source ◽  
Optical Constants ◽  
Free Standing

In this work, the refractive index of beryllium in the photon energy range 20.4–250 eV was experimentally determined. The initial data include measurements of the transmittance of two free-standing Be films with thicknesses of 70 nm and 152 nm, as well as reflectometric measurements of similar films on a substrate. Measurements were carried out at the optics beamline of the BESSY II synchrotron radiation source. The absorption coefficient β was found directly from the transmission coefficient of the films, and the real part of the polarizability δ was calculated from the Kramers–Kronig relations. A comparison is carried out with results obtained 20 years ago at the ALS synchrotron using a similar methodology.

Ellipsometric Determination of the Spectra of Adsorbed Molecules

1971 ◽  
Vol 49 (7) ◽  
pp. 1115-1132 ◽  
Author(s):  
M. J. Dignam ◽  
B. Rao ◽  
M. Moskovits ◽  
R. W. Stobie
Keyword(s):  
Thin Films ◽  
Film Thickness ◽  
Optical Constants ◽  
Order Term ◽  
Second Order ◽  
Lower Sensitivity ◽  
Model Calculations ◽  
The Media ◽  
Reflecting Surfaces ◽  
Optical Behavior

This paper presents a detailed analysis of the application of ellipsometry to obtaining the optical spectra (principally infrared (i.r.)) of molecules adsorbed on reflecting surfaces. Both external and total internal reflections are considered and the conditions for optimum sensitivity examined. A new empirical quantity, the relative complex optical density, is defined which exhibits thin film properties well, particularly in the case of multiple reflection measurements. An explicit expression is derived for this density function (relating it to the optical constants of the media and other system parameters), which is both reasonably simple and correct to second order terms in the film thickness. It is shown that for thin films, no higher order terms need be included, but that in general the second order term must be retained. Various limiting cases are examined to gain insight into the optical behavior of thin films, and to the same end, model calculations performed for CCl4 physically adsorbed on Ag, Ni, Sb, and Ge. In relation to conventional reflection spectroscopy, ellipsometric spectroscopy is shown to have three major advantages: (1) in general, higher sensitivity to adsorbate properties; (2) very much lower sensitivity to absorption of radiation by the adjacent gas phase; (3) more information, permitting the optical constants and film thickness to be determined. Finally, the practicability of the technique is demonstrated by presenting preliminary results for CH3OH reversibly adsorbed on Ag, showing clearly the C—H stretching bands.

Determination of optical constants of Si/ZnO polycrystalline nanocomposites by spectroscopic ellipsometry

2001 ◽  
Vol 16 (12) ◽  
pp. 3554-3559 ◽  
Author(s):  
J. García-Serrano ◽  
N. Koshizaki ◽  
T. Sasaki ◽  
G. Martínez-Montes ◽  
U. Pal
Keyword(s):  
Film Thickness ◽  
Quartz Glass ◽  
Spectroscopic Ellipsometry ◽  
Optical Constants ◽  
Composite Films ◽  
Two Phase ◽  
Glass Substrates ◽  
Optical Functions ◽  
Substrate Film

The optical constants of Si/ZnO composite films grown on quartz glass substrates were determined in the spectral range 1.5–5.0 eV by spectroscopic ellipsometry using a rotating-analyzer ellipsometer. The structure of the samples was modeled by a two-phase (substrate–film) model, and the optical functions of the film were parameterized through different effective medium approximations. The results allowed us to estimate the microstructural film parameters, such as film thickness, the volume fractions of each of the constituents, and optical constants.

OPTICAL WAVEGUIDE FABRICATION AND REFRACTIVE INDEX CHARACTERIZATION OF Nd:LuVO4 THIN FILMS BY PULSED LASER DEPOSITION

2007 ◽  
Vol 14 (06) ◽  
pp. 1079-1082 ◽  
Author(s):  
HONGXIA LI ◽  
XIN WU ◽  
RENGUO SONG ◽  
JIYANG WANG
Keyword(s):  
Thin Films ◽  
Refractive Index ◽  
Pulsed Laser Deposition ◽  
Silica Glass ◽  
Pulsed Laser ◽  
Laser Deposition ◽  
Propagation Mode ◽  
Glass Substrates ◽  
Oriented Polycrystalline ◽  
Waveguide Fabrication

High-quality Nd:LuVO 4 thin films have been grown on silica glass substrates by using a pulsed laser deposition technique. X-ray diffraction results show that the as-deposited Nd:LuVO 4 film is basically oriented polycrystalline, and strong (200) peak was revealed. The waveguide property was characterized by the prism-coupling method. The refractive index of the propagation mode is higher than that of the silica glass substrate which means that the dips correspond to real propagation mode, where the light could be well defined. The surface morphology of the deposited Nd:LuVO 4 films was also observed by using an atomic force microscopy.

scholarly journals Electrical characterization of aluminum (Al) thin films measured by using four- point probe method

2013 ◽  
Vol 8 (2) ◽  
pp. 31-36 ◽  
Author(s):  
GP Panta ◽  
DP Subedi
Keyword(s):  
Thin Films ◽  
Electrical Resistivity ◽  
Film Thickness ◽  
Vapor Deposition ◽  
Physical Vapor Deposition ◽  
Electrical Characterization ◽  
Probe Method ◽  
Glass Substrates ◽  
Engineering And Technology

This paper reports the results of electrical characterization of aluminum thin films. Uniform Al thin films were deposited by physical vapor deposition (PVD) technique on glass substrates. The electrical resistivity of the films as a function of film thickness was studied. These parameters have been measured by four-point probe method. The electrical resistivity was obtained by the measurement of current (in mA) and voltage in (mV) through the probe. The results showed that resistivity of the film decreases linearly with the film thickness in the range of the thickness studied in this work. Kathmandu University Journal of Science, Engineering and Technology Vol. 8, No. II, December, 2012, 31-36 DOI: http://dx.doi.org/10.3126/kuset.v8i2.7322

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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