scholarly journals Depending the Structure and Optical Properties of Cadmium Telluride Films on the Doping process

2018 ◽  
Vol 29 (1) ◽  
pp. 160
Author(s):  
Iman Hameed Khudayer

The purpose of the present paper is to study the effect of doping by different materials on the structure and the optical properties of Cadmium Telluride films which prepared by rate deposition (4.21 nmn/sec) and thickness (≈ 200 nm) in vacuum by use thermal evaporation technique at a substrate temperature (300K), we are studying the effect of doping by different material (Antimony, Aluminum and Silver) on the structural1and optical2 properties of CdTe thin films. The structural properties of these films have been studied by using X-ray diffraction methods. The optical measurements indicated that Cadmium Telluride films have a direct optical energy gap (Egopt), and it decreases when we doped this films by different materials (Sb, Al and Ag) with the same ratio doping. The optical constants refractive index (n), extinction coefficient (k), absorption coefficient (α) and dielectric constants (r and i) were also studied.

this work, the study of optical properties of (As0.5Se0.5 doped with 1% Te) thin films which prepared by thermal vacuum evaporation on glass bases at (R.T) with (100±20) nm thickness deposition rate (1.6nm/s) and study effect of annealing at temperatures (Ta) (348,398,448) K for time (30min) on these properties. The X-ray diffraction technique showed that all prepared films are amorphous in structure at room temperature and annealing films at (348, 398, 448) K. The transmittance spectra of the prepared films fall within a wavelength range (500-1100) nm, and increasing the annealing temperature leads to a decreased in transmission, increased absorption coefficient, and shift of the absorption edge towards low photon energies. The optical measurements showed that the prepared films had an allowed indirect optical energy gap and were found to decrease with the increase of (Ta) within the range (R.T, 348,398,448) K. As indicated by the tails of the localized states, it was observed that they increased by increasing (Ta).


2021 ◽  
Vol 2114 (1) ◽  
pp. 012012
Author(s):  
Tamara S. Hussein ◽  
Ala F. Ahmed

Abstract In this study, the effect of grafting with Iron (Fe) ratios (0.1, 0.3 and 0.5) on the structural and optical properties of cadmium oxide films (CdO) was studied, as these films were prepared on glass bases using the method of pulse laser deposition (PLD). The crystallization nature of the prepared films was examined by X-ray diffraction technique (XRD), which showed that the synthesis of the prepared films is polycrystalline, and Atomic Force Microscope (AFM) images also showed that the increased vaccination with Iron led to an increase in the crustal size ratio and a decrease in surface roughness, The absorption coefficient was calculated and the optical energy gap for the prepared thin films. It was found the absorption decreases and the energy gap decreases with the increase of doping ratio.


2019 ◽  
Vol 15 (32) ◽  
pp. 99-113
Author(s):  
Mahdi Hasan Suhail

Polymer films of PEG and PVA and their blend with differentconcentrations of MnCl2 (0, 2, 4, 6 and 10 %.wt) were study usingcasting technique. The X-ray spectra of pure PEG, PVA andPVA:PEG films and with addition of 2% concentrations from(MnCl2) show amorphous structures. The results for FTIR show theinteraction between the filler and polymer blend results indecreasing crystallinity with rich amorphous phase. Thisamorphous nature confirms the complexation between the filler andthe polymer blend. The optical properties of (PVA:PEG/MnCl2)contain the recording of absorbance (A) and explain that theabsorption coefficient (α), refractive index (n), extinction coefficient(ko) and the dielectric constants (real and imaginary part) increasewith increasing the concentration of Composite (PVA:PEG/MnCl2).The optical energy gap for electrons transitions both are direct andindirect allowed.


Author(s):  
Zehraa N. Abdul-Ameer ◽  
Ibrahim R. Agool

ZnO,CdO,ZnO-CdO nanocomposite were prepared using electrochemical deposition the prepared samples were characterized using X-ray diffraction and the photoluminenscence spectroscopy (PL) to get the surface morphology leading to calculation of optical energy gap .the grain size determined by Scherrer's equation (22-25) nm .through the calculation of Eg ,it was noticed a red shift behavior in ZnO manner due to addition of CdO content


2019 ◽  
Vol 17 (40) ◽  
pp. 77-87
Author(s):  
Suhad A. Hamdan

In this study, pure Co3O4 nano structure and doping with 4 %, and6 % of Yttrium is successfully synthesized by hydrothermal method.The XRD examination, optical, electrical and photo sensingproperties have been studied for pure and doped Co3O4 thin films.The X-ray diffraction (XRD) analysis shows that all films arepolycrystalline in nature, having cubic structure.The optical properties indication that the optical energy gap followsallowed direct electronic transition calculated using Tauc equationand it increases for doped Co3O4. The photo sensing properties ofthin films are studied as a function of time at different wavelengths tofind the sensitivity for these lights.High photo sensitivity doped Co3O4 with 6% of Yttrium, is a118.774% at wavelength 620 nm, while for pure Co3O4 films nosensitivity at the same wavelength. So, higher sensitivity is found fordoping Co3O4 with fast rise and fall times less than 1s.


2009 ◽  
Vol 6 (1) ◽  
pp. 141-149
Author(s):  
Baghdad Science Journal

A polycrystalline CdSe thin films doped with (5wt%) of Cu was fabricated using vacuum evaporation technique in the substrate temperature range(Ts=RT-250)oC on glass substrates of the thickness(0.8?m). The structure of these films are determined by X-ray diffraction (XRD). The X-ray diffraction studies shows that the structure is polycrystalline with hexagonal structure, and there are strong peaks at the direction (200) at (Ts=RT-150) oC, while at higher substrate temperature(Ts=150-250) oC the structure is single crystal. The optical properties as a function of Ts were studied. The absorption, transmission, and reflection has been studied, The optical energy gap (Eg)increases with increase of substrate temperature from (1.65-1.84)eV due to improvement in the structure. The amorphousity of the films decreases with increasing Ts. The films have direct energy gap and the absorption edge was shift slightly towards smaller wavelength for CdSe:Cu thin film with increase of substrate temperature.it was found that the absorption coefficient was decreased with increasing of substrate temperature due to increases the value of(Eg). The CdSe:Cu films showed absorption coefficient in the range (0.94 x104-0.42x104)cm-1at Ts=RT-250 oC. Also the density of state decreases with increasing of substrate temperatures from (0.20-0.07)eV, it is possibly due to the recrystallization by the heating substrate temperatures.. Also the extinction coefficient, refractive index and dielectric constant have been studied.


2016 ◽  
Vol 12 (3) ◽  
pp. 4394-4399
Author(s):  
Sura Ali Noaman ◽  
Rashid Owaid Kadhim ◽  
Saleem Azara Hussain

Tin Oxide and Indium doped Tin Oxide (SnO2:In) thin films were deposited on glass and Silicon  substrates  by  thermal evaporation technique.  X-ray diffraction pattern of  pure SnO2 and SnO2:In thin films annealed at 650oC and the results showed  that the structure have tetragonal phase with preferred orientation in (110) plane. AFM studies showed an inhibition of grain growth with increase in indium concentration. SEM studies of pure  SnO2 and  Indium doped tin oxide (SnO2:In) ) thin films showed that the films with regular distribution of particles and they have spherical shape.  Optical properties such as  Transmission , optical band-gap have been measured and calculated.


2021 ◽  
Vol 19 (5) ◽  
pp. 132-138
Author(s):  
Maan Abd-Alameer Salih ◽  
Q.S. Kareem ◽  
Mohammed Hadi Shinen

In this exploration Poly lactic corrosive (PLA) was orchestrated the ring-opening polymerization Poly lactic corrosive (PLA) blended with poly(3-hexylthiophene) (P3HT) which prepared by solution. Blends thin films Synthesis by spin coating technique and using Tetrahydrofuran (THF) as solvent. PLA powder was 'characterized by' 'X-ray' 'diffraction', '(FT-IR)'. pure Optical properties (PLA), (PLA)/P3HT blends thin films with different percentage of P3HT (0, 1, 2, and 3) wt% were investigated using UV-VS spectroscopy The results showed that the absorption, absorption coefficient, extinction coefficient and conductivity increase with increasing the rate of deformation P3HT, The energy gap decreases with increasing deformation.


2012 ◽  
Vol 510-511 ◽  
pp. 89-97
Author(s):  
G.H. Tariq ◽  
M. Anis-ur-Rehman

To overcome the naturally existing Schottky barrier problem between p-CdTe and any metal, an intermediate semiconductor thin buffer layer is a better choice prior to the final metallization for contact. Among many investigated back contact materials the ZnTe is suitable as a buffer layer. ZnTe thin films were deposited onto glass substrates by the thermal evaporation technique under vacuum ~2×10-5mbar. Undoped ZnTe thin films are highly resistive, extrinsic doping of Cu was made to improve the electrical conductivity. Films were doped by immersing in Cu NO32.5H2O solutions for Cu doping. To optimize the growth parameters the prepared films were characterized using various techniques. The structural analysis of these films was performed by X-ray diffraction (XRD) technique and optical transmission. X-ray diffraction identified the phases present in these films and also observed that the prepared films were polycrystalline. Also the spectral dependence of absorption coefficient was determined from spectrophotometer. Energy band gap index were calculated from obtained optical measurements data.


2010 ◽  
Vol 295-296 ◽  
pp. 11-17
Author(s):  
S.A. Aly

The optical properties of tungsten oxide (WO3) films prepared by DC sputtering on unheated glass substrates with different film thicknesses have been studied. The structural characteristics of the samples were investigated using X-ray diffraction. The optical properties of the prepared films were studied by transmittance and reflectance measurements, and the integrated transmittance (TUV, TVIS, and TNIR) and absorption (AUV, AVIS, and ANIR) in UV, VIS and NIR regions. The integrated UV absorption and transmittance are varied with the film thicknesses, also, no remarkable change in VIS and NIR regions was observed. The dependence of refractive index as well as extinction coefficient on wavelength was also reported. The energy gap was calculated and is located around 3.25 eV.


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