scholarly journals Epitaxial Growth and Optical Properties of Laser Deposited CdS Thin Films

Coatings ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 87
Author(s):  
Atef S. Gadalla ◽  
Hamdan A. S. Al-shamiri ◽  
Saad Melhi Alshahrani ◽  
Huda F. Khalil ◽  
Mahmoud M. El Nahas ◽  
...  

In this study, cadmium Sulfide (CdS) thin films were synthesized on quartz substrates using an infrared pulsed laser deposition (IR-PLD) technique under high vacuum (~10−6 Torr) conditions. X-ray diffraction was used to evaluate the structural features. According to X-ray analysis, the deposited CdS films are crystalline and have a favored orientation on a plane (110) of an orthorhombic. The peak intensity and the average crystallite size increases with increasing the film thickness. After annealing at 300 °C, the orthorhombic phase transformed into a predominant hexagonal phase and the same result was obtained by SEM photographs as well. Spectrophotometric measurements of transmittance and reflectance of the CdS films were used to derive optical constants (n, k, and absorption coefficient α). The optical band gap energy was found to be 2.44 eV. The plasma plume formation and expansion during the film deposition have also been discussed. The photocurrent response as a function of the incident photon energy E (eV) at different bias voltages for different samples of thicknesses (85, 180, 220 and 340 nm) have been studied, indicating that the photocurrent increases by increasing both the film thickness and photon energy with a peak in the vicinity of the band edge. Thus, the prepared CdS films are promising for application in optoelectronic field.

2021 ◽  
Author(s):  
Hamdan Ali Sultan Ali Sultan Al-shamiri ◽  
Atef S. Gadalla ◽  
Huda F. Khalil ◽  
Mahmoud M. El Nahas ◽  
Mohamed A. Khedr

Abstract Cadmium Sulfide (Cds) thin films were synthesized on quartz substrates using infrared pulsed laser deposition (IR-PLD) technique under high vacuum (~ 10− 6 Torr). X-ray diffraction was used to evaluate the structural features. According to X-ray analysis the deposited CdS films are crystalline and have a favored orientation on a plane (110) of an orthorhombic system and the peak intensity and the average crystallite size increases with increasing the film thickness. After annealing at 300oC the orthorhombic phase transformed into predominant hexagonal phase and the same result was obtained by SEM photographs. Spectrophotometric measurements of transmittance and reflectance of the Cds films were used to derive optical constants (n, k and absorption coefficient α). The optical band gap energy was found to be 2.44 eV. The plasma plume formation and expansion during the film deposition have been discussed. The photocurrent response as a function of the incident photon energy E (eV) at different bias voltages for different samples of thicknesses (85, 180, 220 and 340 nm) have been studied, indicating that the photocurrent increases by increasing both the film thickness and photon energy with a peak in the vicinity of the band edge. Thus, the prepared Cds films are promising for application in optoelectronic field.


1996 ◽  
Vol 426 ◽  
Author(s):  
Yuming Zhu ◽  
Dull Mao ◽  
D. L. Williamson ◽  
J. U. Trefny

AbstractChemical-bath-deposited CdS thin films from an ammonia-thiourea solution have been studied by x-ray diffraction, surface profilometry, ellipsometry, and other techniques. The compactness of the CdS films, structural properties of the films, and the growth mechanism have been investigated. For the deposition conditions used, we found that the film compactness reaches its maximum at a deposition time of 35 minutes. Films grown at longer deposition times are less compact, consistent with the CdS duplex layer structure proposed previously. This transition from compact layer growth to porous layer growth is important for depositing CdS films in solar cell applications. Based on x-ray diffraction (XRD) studies, we were able to determine the crystal phase, lattice constant, and other structural properties.


2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
E. Flores-García ◽  
M. A. Hernández-Landaverde ◽  
P. González-García ◽  
R. Ramírez-Bon

Cadmium sulfide (CdS) thin films were deposited, on glass substrates, at 70°C for 120 min using an ammonium-free chemical bath deposition process. After deposition, the films were placed in a CuCl2 solution for 45, 60, 75, and 90 min, respectively, for their ion exchange, generating CdxCu1-xS films. The obtained films were analyzed by X-ray diffraction, Raman spectroscopy, X-ray wavelength dispersion spectrometry, and scanning electron microscopy. The reference CdS films showed a homogeneous appearance and a yellowish color; elapsing the immersion time, the films changed their color showing a greenish appearance. The X-ray analysis indicated that the CdS films developed a hexagonal structure with preferential orientation along the plane (002). During the ion exchange, a decrease in the intensity of the reflection (002) was observed as well as a slight displacement of this reflection towards higher values of 2θ derived from the substitution of Cd atoms by Cu atoms. The WDS analysis revealed that approximately 10% of the cadmium atoms were replaced by copper ones after 90 min of immersion.


2011 ◽  
Vol 347-353 ◽  
pp. 3477-3480
Author(s):  
Liang Min Cai ◽  
Jian Huang ◽  
Jia Wei Jiang ◽  
Jun Le ◽  
Wei Min Shi ◽  
...  

CdS films were prepared by R.F. magnetron sputtering method. The effects of vapor CdCl2treatment on the properties of CdS films were studied. The vapor CdCl2thermal treatment at different temperature was employed in a CSS device, using CdCl2powder as evaporant. The structural and optical properties of CdS films were investigated by x-ray diffraction (XRD), PL spectra, and transmittance spectra, respectively. The results revealed that the CdS films had a structure of hexagonal wurtzite with a preferential orientation of the (002) plane. A better crystal quality and larger grain size, which are good for the solar cell application, were observed in the CdS samples annealed with CdCl2Subscript text.


2013 ◽  
Vol 750-752 ◽  
pp. 1901-1905 ◽  
Author(s):  
Kai Zou ◽  
Rong Ping Li ◽  
Yong Sheng Liu ◽  
Lei Tian ◽  
Song Feng

Using chemical bath deposition (CBD) deposited CdS thin films for two times and prepared CdS films contained different thickness Dy-doping layer by connecting using the vacuum electron beam evaporation method, then studied the structure, surface morphology, optical and electrical properties of the films. The results show that no-doped CdS films are the cubic structure and preferentially oriented in the (111) directions. Its conductive type is N type. After Dy doping the CdS thin films are mixed structure by cubic and hexagonal phase, the conductive type is still N type, the uniformity and compactness of the films are improved. At the same time, the proportion of Cd and S atoms in Dy-doping films are more close to the stoichiometric ratio. Dy-doping can also reduce the resistivity of the films, result in an increase of carrier concentration and improve the transmittance in the visible region.


2019 ◽  
Vol 12 (25) ◽  
pp. 138-147
Author(s):  
Haidar Jwad Abdul-Ameer Al-Rehamey

Cadmium sulfide (CdS) thin films with n-type semiconductor characteristics were prepared by flash evaporating method on glass substrates. Some films were annealed at 250 oC for 1hr in air. The thicknesses of the films was estimated to be 0.5µ by the spectrometer measurement. Structural, morphological, electrical, optical and photoconductivity properties of CdS films have been investigated by X-ray diffraction, AFM, the Hall effect, optical transmittance spectra and photoconductivity analysis, respectively. X-ray diffraction (XRD) pattern shows that CdS films are in the stable hexagonal crystalline structure. Using Debye Scherrerś formula, the average grain size for the samples was found to be 26 nm. The transmittance of the samples was determined from optical trasmittance spectra. It is observed that the direct band gap energy for as deposited and annealed films are (2.55, 2.45) eV, respectively. The effect of annealing at 250 oC for 1hr in air on optical and photoconductivity of films under various intensity of illuminations (43.81 and 115.12) mW/cm2 was studied. The dark and photocurrents of the annealed films were found to be greater than that of as deposited.


Author(s):  
S.M. Patil ◽  
P.H. Pawar

Nanocrystalline CdS thin films were successfully prepared using simple chemical bath deposition technique. Cadmium sulphate, thiourea and deionised water were used as starting precursor solution. The prepared thin films were characterized using X-ray diffractogram (XRD), Scanning electron microscope (SEM), elemental composition using energy dispersive spectrophotometer (EDAX) and optical band gap (UV-Spectroscopy).X-ray diffractogram reveals that present of cubic and hexagonal phase. The thickness, crystallite size and grain size were observed to be increase with increase operating temperature of bath while optical band gap energy slightly decreases. Effect of deposition temperature on physical, structural, microstructural, electrical and optical properties of these films was studied and presented in the present investigation. Prepared thin films shows good response towards photoconducting in presence and absent of light


2011 ◽  
Vol 306-307 ◽  
pp. 265-268
Author(s):  
Xue Yan Zhang ◽  
Xiao Yu Liu ◽  
Han Bin Wang ◽  
Xi Jian Zhang ◽  
Qing Pu Wang ◽  
...  

Cadmium sulfide (CdS) thin films with (111) preferential orientation were grown on glass substrates at room temperature by radio frequency (R.F.) magnetron sputtering. The structural and optical properties of CdS films have been investigated by X-ray diffraction, Scanning Electron Microscope micrographs, PL spectra and transmittance spectra. The grain sizes have been evaluated. The transmission spectra of the obtained films reveal a relatively high transmission coefficient (80%) in the visible range. All these results show that the grain sizes increased while the optical band gap decreased with increasing the thickness of CdS films.


Coatings ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 510
Author(s):  
Yongqiang Pan ◽  
Huan Liu ◽  
Zhuoman Wang ◽  
Jinmei Jia ◽  
Jijie Zhao

SiO2 thin films are deposited by radio frequency (RF) plasma-enhanced chemical vapor deposition (PECVD) technique using SiH4 and N2O as precursor gases. The stoichiometry of SiO2 thin films is determined by the X-ray photoelectron spectroscopy (XPS), and the optical constant n and k are obtained by using variable angle spectroscopic ellipsometer (VASE) in the spectral range 380–1600 nm. The refractive index and extinction coefficient of the deposited SiO2 thin films at 500 nm are 1.464 and 0.0069, respectively. The deposition rate of SiO2 thin films is controlled by changing the reaction pressure. The effects of deposition rate, film thickness, and microstructure size on the conformality of SiO2 thin films are studied. The conformality of SiO2 thin films increases from 0.68 to 0.91, with the increase of deposition rate of the SiO2 thin film from 20.84 to 41.92 nm/min. The conformality of SiO2 thin films decreases with the increase of film thickness, and the higher the step height, the smaller the conformality of SiO2 thin films.


1992 ◽  
Vol 270 ◽  
Author(s):  
Haojie Yuan ◽  
R. Stanley Williams

ABSTRACTThin films of pure germanium-carbon alloys (GexC1−x with x ≈ 0.0, 0.2, 0.4, 0.5, 0.6, 0.8, 1.0) have been grown on Si(100) and A12O3 (0001) substrates by pulsed laser ablation in a high vacuum chamber. The films were analyzed by x-ray θ-2θ diffraction (XRD), x-ray photoelectron spectroscopy (XPS), Auger electron spectroscopy (AES), conductivity measurements and optical absorption spectroscopy. The analyses of these new materials showed that films of all compositions were amorphous, free of contamination and uniform in composition. By changing the film composition, the optical band gap of these semiconducting films was varied from 0.00eV to 0.85eV for x = 0.0 to 1.0 respectively. According to the AES results, the carbon atoms in the Ge-C alloy thin film samples has a bonding configuration that is a mixture of sp2 and sp3 hybridizations.


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