INVESTIGATING ANNEALING EFFECT ON OPTICAL PROPERTIES OF Cd0.8Zn0.2S THIN FILMS

2014 ◽  
Vol 21 (05) ◽  
pp. 1450073 ◽  
Author(s):  
SOMAYEH AZIZI ◽  
HAMID REZAGHOLIPOUR DIZAJI ◽  
MOHAMMAD HOSSEIN EHSANI ◽  
SEYED FEYZOLAH GHAVAMI MIRMAHALLE

Cd 0.8 Zn 0.2 S thin films deposited on glass substrates by thermal evaporation method were annealed at different temperatures for the first time in order to investigate annealing effect on optical properties. The compositional, structural of nanoparticles precursor synthesized using microwave irradiation method and optical properties of the films were studied using energy dispersive X-ray (EDX), X-ray diffraction, transmission electron microscopy (TEM), and UV-visible spectrophotometer techniques. The annealed films were found to have hexagonal Wurtzite structure with strong preferential orientation along the (002) diffraction peak. Important optical parameters such as extinction coefficient and refractive index revealed the effect of heat treatment on the deposited thin layers. A reduction in the band gap energy from 2.41 eV to 2.29 eV was observed for the annealed samples.

2021 ◽  
Author(s):  
Haleh Kangarlou ◽  
Somayeh Asgary

Abstract Mercury sulfide films were deposited on amorphous glass substrates from aqueous solutions by chemical bath deposition method (CBD) at same temperature and different deposition times. Produced layers were post annealed at 250°C about one hour. X-ray diffraction (XRD) was used to study of film’s crystalline structural. Their optical properties were measured by spectrophotometry in the spectra range of 400-850 nm, Kramers-Kronig method was used for the analysis of reflectivity curves of HgS films to obtain the optical constants of films in order to investigation of relation between deposition time and optical properties. According to X-ray diffraction details, all thin films showed crystalline phase with a preferential growth along the (220) planes. Optical results have been shown photolminisance property for HgS produced thin films. By increasing deposition time, the dielectric property, refractive index and band gap values are increased.


2019 ◽  
Vol 87 (1) ◽  
pp. 10301 ◽  
Author(s):  
Hajar Ftouhi ◽  
Zouhair El Jouad ◽  
Mohammed Jbilou ◽  
Mustafa Diani ◽  
Mohammed Addou

In this paper, transparent conducting thin films based on both undoped and vanadium (V) doped zinc oxide Zn1−xVx O (x = 3, 5, 7 at.%), were studied. The thin films were prepared using a simple low cost deposition technique called spray pyrolysis (SP). The layers were deposited onto preheated glass substrates at 450 °C. The effect of vanadium on the microstructural, the morphological and the optical properties of ZnO material was carried out using X-ray diffractometer (XRD), micro Raman spectroscope, scanning electron microscope (SEM), energy dispersive analysis by X-ray (EDX) and UV-Vis-NIR spectrophotometer. We have demonstrated that doping with 3 at.% of V enhances the crystallinity of the films by estimating the grain size value, the dislocation density and the residual stress. Also, the SEM images have demonstrated that the vanadium concentrations do effect in the thin films morphology, from hexagonal-shaped grains to rounded crystals for higher doping concentrations. The optical analysis revealed that doping with 3 at.% of vanadium shows a remarkable enhancement in the average transmittance in the visible range 89% and in the band gap energy (3.3 eV). Moreover, the disorder inside the samples was estimated using Urbach equation. Therefore, the microstructural, the morphological and the optical results approve that doping with 3 at.% of V in ZnO lattices gives interesting results for the optical window material for solar cells application.


2019 ◽  
Vol 15 (34) ◽  
pp. 1-14
Author(s):  
Bushra A. Hasan

Lead selenide PbSe thin films of different thicknesses (300, 500, and 700 nm) were deposited under vacuum using thermal evaporation method on glass substrates. X-ray diffraction measurements showed that increasing of thickness lead to well crystallize the prepared samples, such that the crystallite size increases while the dislocation density decreases with thickness increasing. A.C conductivity, dielectric constants, and loss tangent are studied as function to thickness, frequency (10kHz-10MHz) and temperatures (293K-493K). The conductivity measurements confirm confirmed that hopping is the mechanism responsible for the conduction process. Increasing of thickness decreases the thermal activation energy estimated from Arhinus equation is found to decrease with thickness increasing. The increase of thickness lead to reduce the polarizability α while the increasing of temperature lead to increase α.


Author(s):  
Atefeh Nazari Setayesh ◽  
Hassan Sedghi

Background: In this work, CdS thin films were synthesized by sol-gel method (spin coating technique) on glass substrates to investigate the optical behavior of the film. Methods: Different substrate spin coating speeds of 2400, 3000, 3600 rpm and different Ni dopant concentrations of 0 wt.%, 2.5 wt.%, 5 wt.%) were investigated. The optical properties of thin films such as refraction index, extinction coefficient, dielectric constant and optical band gap energy of the layers were discussed using spectroscopic ellipsometry method in the wavelength range of 300 to 900 nm. Results: It can be deduced that substrate rotation speed and dopant concentration has influenced the optical properties of thin films. By decreasing rotation speed of the substrate which results in films with more thicknesses, more optical interferences were appeared in the results. Conclusion: The samples doped with Ni comparing to pure ones have had more optical band gap energy.


2013 ◽  
Vol 665 ◽  
pp. 159-167
Author(s):  
M.S. Jani ◽  
H.S. Patel ◽  
J.R. Rathod ◽  
K.D. Patel ◽  
V.M. Pathak ◽  
...  

In this paper structural and optical properties of CdSe thin films with different thickness deposited by thermal evaporation under vacuum onto glass substrates are presented. The structural investigations performed by means of XRD technique showed that the films have a polycrystalline and hexagonal (würtzite) structure. The values of some important parameters of the studied films (absorption coefficient and optical bandgap energy) are determined from transmission spectra. The values of the optical bandgap energy (Eg) calculated from the absorption spectra, ranged between 1.67 - 1.74 eV.


Author(s):  
Emna Gnenna ◽  
Naoufel Khemiri ◽  
Minghua Kong ◽  
Maria Isabel Alonso ◽  
Mounir Kanzari

Sb2S3 powder was successfully synthesized by solid state reaction technique using high-purity elemental antimony and sulfur. Sb2S3 thin films were deposited on unheated glass substrates by one step thermal evaporation and annealed under vacuum atmosphere for 2 hours at different temperatures 150, 200 and 250 °C. Different characterization techniques were used to better understand the behavior of the Sb2S3 material. X-ray diffraction (XRD) and Raman spectroscopy confirmed the formation of pure Sb2S3 powder with lattice parameters a = 11.07 Å, b = 11.08 Å and c = 3.81 Å. The effect of vacuum annealing temperature on the properties of the films was studied. XRD analysis revealed that as-deposited and annealed films at 150ºC were amorphous in nature whereas those annealed at T ≥ 200°C were polycrystalline with a preferred orientation along (201) plane. The crystallite size of the polycrystalline films showed a decrease from 75.8 to 62.9 nm with the increase of the annealing temperature from 200 to 250 °C. The Raman analysis showed several peaks corresponding to the stibnite Sb2S3 phase. The surface morphology of the films was examined by atomic force microscopy (AFM). The surface roughness decreases slightly as the transformation from the amorphous to the crystalline phase occurs. The chemical compositions of Sb2S3 films were analyzed by energy dispersive X-ray spectroscopy (EDS), revealing that all films were Sb-rich. The optical parameters were estimated from the transmittance and reflectance spectra recorded by UV-Vis spectroscopy. A reduction in the direct band gap energy from 2.12 to 1.70 eV with the increase of annealing temperature was also found.


2016 ◽  
Vol 40 (2) ◽  
pp. 179-186 ◽  
Author(s):  
Md Saiful Islam ◽  
Chitra Das ◽  
Mehnaz Sharmin ◽  
Kazi Md Amzad Hussain ◽  
Shamima Choudhury

Effects of indium doping (concentration 0.2, 0.3 and 0.4%) on the optical properties of GaAs thin films were studied. Thin films of 600 nm were grown onto chemically and ultrasonically cleaned glass substrate by thermal evaporation method in high vacuum (~10-4 Pa) at 50°C fixed substrate temperature. The samples were annealed for 15 minutes at a fixed temperature of 200°C. The thicknesses of films were being measured in situ by a quartz crystal thickness monitor during deposition. The transmittance and reflectance data were found using UV-VIS-NIR spectrophotometer in the photon wavelength range of 310 ~ 2500 nm. These data were utilized to compute the absorption coefficient, refractive index, extinction co-efficient and band gap energy of the studied films. Here transmittance was found 78 for 0.2% indium doping concentration. The band gap energy decreased with the increase of doping concentration.Journal of Bangladesh Academy of Sciences, Vol. 40, No. 2, 179-186, 2016


2009 ◽  
Vol 609 ◽  
pp. 243-247 ◽  
Author(s):  
H. Moualkia ◽  
S. Hariech ◽  
M.S. Aida

The present work deals with the preparation and characterization of cadmium sulfur (CdS) thin films. These films are prepared by chemical bath deposition on the well cleaned glass substrates. The thickness of the samples was measured by using profilometer DEKTAK, structural and optical properties were studied by X-ray diffraction analysis, and UV-visible spectrophotometry. The optical properties of the films have been investigated as a function of temperature. The band gap energy and Urbach energy were also investigated as a function of temperature. From the transmittance data analysis the direct band gap ranges from 2.21 eV to 2.34 eV. A dependence of band gap on temperature has been observed and the possible raisons are discussed. Transmission spectra indicates a high transmission coefficient (75 %). Structural analysis revealed that the films showed cubic structure, and the crystallite size decreased at a higher deposition temperature.


2013 ◽  
Vol 591 ◽  
pp. 297-300
Author(s):  
Huan Ke ◽  
Shu Wang Duo ◽  
Ting Zhi Liu ◽  
Hao Zhang ◽  
Xiao Yan Fei

ZnS films have been deposited on glass substrates by chemical bath deposition (CBD). The optical and structural properties were analyzed by UV-VIS spectrophotometer and X-ray diffraction (XRD). The results showed that the prepared thin films from the solution using N2H4 as second complexing agent were thicker than those from the solution without adding N2H4 in; this is due to using second complexing agent of N2H4, the deposition mechanisms change which is conductive to heterogeneous deposition. When using N2H4 as second complexing agent, the crystallinity of ZnS thin films improved with a significant peak at 2θ=28.96°which can be assigned to the (111) reflection of the sphalerite structure. The transmittances of the prepared films from the solution adding N2H4 in as second complexing agent were over 85%, compared to those from the solution without N2H4 (over 95%). The band gaps of the ZnS films from the solution using N2H4 as second complexing agent were larger (about 4.0eV) than that from those from the solution without N2H4 (about 3.98eV), which indicated that the prepared ZnS films from the solution adding N2H4 in as second complexing agent were better used as buffer layer of solar cells with adequate optical properties. In short, using N2H4 as second complexing agent, can greatly improve the optical and structural properties of the ZnS thin films.


2005 ◽  
Vol 865 ◽  
Author(s):  
Hiroki Ishizaki ◽  
Keiichiro Yamada ◽  
Ryouta Arai ◽  
Yasuyuki Kuromiya ◽  
Yukari Masatsugu ◽  
...  

AbstractAgGa5Se8 and Ag(In1-xGax)Se2 thin films with different Ag/Ga atomic ratios have been deposited on the corning 1737 glass substrates by molecular beam epitaxy (MBE) system. This crystallographic property of AgGa5Se8 thin films has been investigated by x-ray diffraction and rietveld analysis. These films had the tetragonal structure with the space group of P-42m, regardless of Ag/Ga atomic ratio. The lattice parameters and the optical band gap energy decreased with an increase in the Ag/Ga atomic ratio. Thus, the structural and optical properties of these AgGa5Se8 thin films were controlled by the Ag/Ga atomic ratio.


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