scholarly journals Visual and Surface Properties of CdTe Thin Films on CdS/FTO Glass Substrates

Author(s):  
Ramya K ◽  
Yuvaraja T

<p>Cadmium telluride (CdTe) thin film material was deposited ontop of Cadmium Sulfide (CdS) substrate using vacuum evaporation technique. The sample was characterized using X-ray diffraction(XRD) and UV-VIS-NIR spectroscopy. XRD studies revealed that the sample was polycrystalline in nature. The SEM image showed that the sample is columnar in structure and the grains are uniform. Optical band gap of the CdTe thin film was estimated from transmittance and reflectance data and it was found 1.53eV.The structural, optical and surface properties of the film showed that the CdTe thin film materials can be used for fabrication of CdTe thin film solar cell.</p>

Author(s):  
Ramya K ◽  
Yuvaraja T

<p>Cadmium telluride (CdTe) thin film material was deposited ontop of Cadmium Sulfide (CdS) substrate using vacuum evaporation technique. The sample was characterized using X-ray diffraction(XRD) and UV-VIS-NIR spectroscopy. XRD studies revealed that the sample was polycrystalline in nature. The SEM image showed that the sample is columnar in structure and the grains are uniform. Optical band gap of the CdTe thin film was estimated from transmittance and reflectance data and it was found 1.53eV.The structural, optical and surface properties of the film showed that the CdTe thin film materials can be used for fabrication of CdTe thin film solar cell.</p>


2013 ◽  
Vol 665 ◽  
pp. 297-301
Author(s):  
Kiran Kumar Patel ◽  
K.D. Patel ◽  
Mayur Patel ◽  
Keyur S. Hingarajiya ◽  
V.M. Pathak

Tin Selenide thin films have been deposited using thermal evaporation technique on chemically and ultrasonically cleaned glass substrates. The stoichiometry of deposited films has been studied using Energy Dispersive Analysis of X-rays (EDAX).The orthorhombic structure and polycrystalline nature of the films were also revealed by X-ray diffraction (XRD) and Transmission Electron Microscopy (TEM) analysis. The well characterized thin film of SnSe was then used to fabricate Ag/p-SnSe/In Schottky barrier diode. The I-V characteristics of prepared diodes have been investigated over the temperature range of 303 K to 393 K. The forward biased I-V characteristics of prepared structure has been analyzed using TE theory and different device parameters have been evaluated and discussed in present paper. The Richardson constant was also determined from the conventional Richardson plot and it is found close to the reported value.


2018 ◽  
Vol 15 (2) ◽  
pp. 227-233 ◽  
Author(s):  
Baghdad Science Journal

A comparative investigation of gas sensing properties of SnO2 doped with WO3 based on thin film and bulk forms was achieved. Thin films were deposited by thermal evaporation technique on glass substrates. Bulk sensors in the shape of pellets were prepared by pressing SnO2:WO3 powder. The polycrystalline nature of the obtained films with tetragonal structure was confirmed by X-ray diffraction. The calculated crystalline size was 52.43 nm. Thickness of the prepared films was found 134 nm. The optical characteristics of the thin films were studied by using UV-VIS Spectrophotometer in the wavelength range 200 nm to 1100 nm, the energy band gap, extinction coefficient and refractive index of the thin film were 2.5 eV , 0.024 and 2.51, respectively. Hall measurements confirmed that the films are n-type. The NO2 sensing characteristics of the SnO2:WO3 sensors were studied with various temperatures and NO2 gas concentrations. Both thin film and bulk sensors showed maximum sensitivity at temperature of 250 oC. Thin film sensors showed enhanced response in comparison to that of pellets.


2013 ◽  
Vol 665 ◽  
pp. 254-262 ◽  
Author(s):  
J.R. Rathod ◽  
Haresh S. Patel ◽  
K.D. Patel ◽  
V.M. Pathak

Group II-VI compounds have been investigated largely in last two decades due to their interesting optoelectronic properties. ZnTe, a member of this family, possesses a bandgap around 2.26eV. This material is now a day investigated in thin film form due to its potential towards various viable applications. In this paper, the authors report their investigations on the preparation of ZnTe thin films using vacuum evaporation technique and their structural and optical characterizations. The structural characterization, carried out using an X-ray diffraction (XRD) technique shows that ZnTe used in present case possesses a cubic structure. Using the same data, the micro strain and dislocation density were evaluated and found to be around 1.465×10-3lines-m2and 1.639×1015lines/m2respecctively. The optical characterization carried out in UV-VIS-NIR region reveals the fact that band gap of ZnTe is around 2.2eV in present case. In addition to this, it was observed that the value of bandgap decreases as the thickness of films increases. The direct transitions of the carries are involved in ZnTe. Using the data of UV-VIS-NIR spectroscopy, the transmission coefficient and extinction coefficient were also calculated for ZnTe thin films. Besides, the variation of extinction coefficient with wavelength has also been discussed here.


2020 ◽  
Vol 21 (1) ◽  
pp. 8
Author(s):  
Emy Mulyani ◽  
Tjipto Sujitno ◽  
Dessy Purbandari ◽  
Ferdiansjah Ferdiansjah ◽  
Sayono Sayono

This paper presents the research on the growth of ZnS:Ag:Cu thin film on a glass substrate as a radio-luminescent material. The SRIM/TRIM software is used to determine the optimum thickness based on an energy deposition depth of 5.485 MeV Am 241 alpha radiation source on ZnS:Ag:Cu material. To increase the adhesive strength of the coating, initially, the glass substrate is etched using a plasma glow discharged at 280°C for 15 minutes. Multiple coatings of ZnS:Ag:Cu were  etched on the glass substrate; this was carried out using a thermal evaporation technique to achieve the optimal thickness (based on SRIM/TRIM simulation). The thin film thickness was observed using a scanning electron microscope (SEM). The optical properties of the un-etched, etched glass substrate and thin-film were characterized using UV-Vis spectrometer. Based on SRIM/TRIM simulation, the optimal thickness is 22 mm which can be achieved by coating three times. From optical properties of ZnS:Ag:Cu thin film and after being analysed using Taue plot method, it is found that the energy gap of ZnS:Ag:Cu thin film is 2.48 eV. It can be concluded that the addition of Ag and Cu doped decrease the energy gap of ZnS (3.66 eV).


1999 ◽  
Vol 562 ◽  
Author(s):  
C. Liu ◽  
L. Shen ◽  
H. Jiang ◽  
D. Yang ◽  
G. Wu ◽  
...  

ABSTRACTThe Ni80Fe20/Fe50Mn50,thin film system exhibits exchange bias behavior. Here a systematic study of the effect of atomic-scale thin film roughness on coercivity and exchange bias is presented. Cu (t) / Ta (100 Å) / Ni80Fe20 (100 Å) / Fe50Mno50 (200 Å) / Ta (200 Å) with variable thickness, t, of the Cu underlayer were DC sputtered on Si (100) substrates. The Cu underlayer defines the initial roughness that is transferred to the film material since the film grows conformal to the initial morphology. Atomic Force Microscopy and X-ray diffraction were used to study the morphology and texture of the films. Morphological characterization is then correlated with magnetometer measurements. Atomic Force Microscopy shows that the root mean square value of the film roughness exhibits a maximum of 2.5 Å at t = 2.4 Å. X-ray diffraction spectra show the films are polycrystalline with fcc (111) texture and the Fe50Mn50 (111) peak intensity decreases monotonically with increasing Cu thickness, t. Without a Cu underlayer, the values of the coercivity and loop shift are, Hc = 12 Oe and Hp = 56 Oe, respectively. Both the coercivity and loop shift change with Cu underlayer thickness. The coercivity reaches a maximum value of Hc= 36 Oe at t = 4 Å. The loop shift exhibits an initial increase with t, reaches a maximum value of HP = 107 Oe at t = 2.4 Å, followed by a decrease with greater Cu thickness. These results show that a tiny increase in the film roughness has a huge effect on the exchange bias magnitude.


2019 ◽  
Vol 2019 ◽  
pp. 1-9 ◽  
Author(s):  
Hiral Raval ◽  
B. B. Parekh ◽  
K. D. Parikh ◽  
M. J. Joshi

Good quality single crystals of organic imidazolium L-Tartrate (IMLT) are grown up from aqueous solution by slow solvent evaporation technique. Various structural parameters and monoclinic crystal structure have been confirmed using powder X-ray diffraction method. The presence of various functional groups has been identified by ATR-FTIR. UV-Vis-NIR spectroscopy has shown more than 60% of optical transparency with the lower UV cutoff at 245nm. The optical band gap value of the material is evaluated to be 4.8 eV. Other optical parameters such as refractive index, optical and electrical conductivity, Urbach energy, extinction coefficient, and optical and electrical susceptibility have been evaluated from transmission spectrum data. The above essential parameters manifest appropriate usage of IMLT as an NLO material. The thermogravimetric analysis indicates high thermal stability of material up to 214°C. Apart from that, the dielectric study at various temperatures confirms decrement of dielectric constant and dielectric loss at higher frequencies. The efficiency of Second Harmonic Generation (SHG) is found to be 3.5 times that of the KDP crystals. A range of analysis suggests suitability and potentiality of IMLT crystal for various optoelectronic applications.


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.


2004 ◽  
Vol 820 ◽  
Author(s):  
Jaap M.J. den Toonder ◽  
Auke R. van Dijken

AbstractThe mechanical properties of the thin film materials used in RF-MEMS are crucial for the reliability and proper functioning of the devices. In this paper we study a large number of aluminum alloys as possible RF-MEMS thin film materials. The yield strength and creep properties are measured using nano-indentation. The results show that the mechanical properties of thin aluminum films can be improved substantially by alloying elements. Of the alloys studied in this paper, AlCuMgMn in particular seems quite promising as a thin film material for RF MEMS, having both high yield strength and little creep. Using X-ray diffraction and electron microscopy, the observed effects are partly explained.


2011 ◽  
Vol 418-420 ◽  
pp. 712-716 ◽  
Author(s):  
Shuai Zhang ◽  
Shu Ying Cheng ◽  
Hong Jie Jia ◽  
Hai Fang Zhou

Metallic-doping chalcogenide compounds have attracted significant interest in application of photovoltaic devices recently. In this article, Al-doped SnS films with a thickness of about 500 nm have been deposited on glass substrates by thermal evaporation technique. Al-doping concentration (from 0 at. % to 15 at.%) in the SnS films can be controlled accurately by varying Al layer thickness. The effects of Al–doping on the physical properties of the films have been investigated by X-ray diffraction, scanning electron microscopy, ultraviolet-visible-near infrared spectroscopy measurements and Hall effect measurement system. All the films are orthorhombic SnS with preferred (111) crystallites orientation, and they are of p-type conductivity. With the increasing of Al-doping concentration, the evaluated direct band gap Edir of the SnS: Al films decreases from 1.50eV to 1.29eV and the conductivities of the films increase. Therefore, the optical and semiconducting properties of the SnS films have been improved by Al-doping.


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