Chromium oxide (Cr2O3) doped ZnO nanoparticles were prepared by pulsed laser deposition (PLD) technique at different concentration ratios (0, 3, 5, 7 and 9 wt %) of ZnO on glass substrate. The effects of ZnO dopant on the average crystallite size of the synthesized nanoparticles was examined By X-ray diffraction. The morphological features were detected using atomic force microscopy (AFM). The optical band gap value was observed to range between 2.78 to 2.50 eV by UV-Vis absorption spectroscopy, with longer wavelength shifted in comparison with that of the bulk Cr2O3 (~3eV). Gas sensitivity, response, and recovery times of the sensor in the presence of NH3 gas were studied and discussed. In the present work, we found that the sensitivity was increased upon increasing the concentration ratio from 3 to 5%wt of ZnO, whereas it was decreased again over that value. Also, we found that the sensitivity was increased when increasing operating temperature, while the response time was decreased. The optimum concentrations ratio for NH3 gas sensitivity at 5%wt ZnO revealed sensitivity of 66.67% and response time of 14s at operating temperature of 300oC and 700mJ PLD energy.
In this research, deposition of titanium oxide (TiO2) and vanadium oxide (V2O5) thin film in different mixing percentage (0, 25 ,50, 75 and100)% on the substrate of glass .The coating thickness was ( 50 nm ).
In this research contact angle was measured and the effect of weather conditions. Results showed that the value of the contact angle of the prepared films reached its highest value at 50% (TiO2+V2O5) was 160º.
The results showed that the optical transmittance of TiO2 and V2O5 thin film decrease with increasing the deposition angle and decrease with increasing V2O5 pro
... Show MoreIn the present work, pulsed laser deposition (PLD) technique was applied to a pellet of Chromium Oxide (99.999% pure) with 2.5 cm diameter and 3 mm thickness at a pressure of 5 Tons using a Hydraulic piston. The films were deposited using Nd: YAG laser λ= (4664) nm at 600 mJ and 400 number of shot on a glass substrate, The thickness of the film was (107 nm). Structural and morphological analysis showed that the films started to crystallize at annealing temperature greater than 400 oC. Absorbance and transmittance spectra were recorded in the wavelength range (300-
4400) nm before and after annealing. The effects of annealing temperature on absorption coefficient, refractive index, extinction coefficient, real and imaginary parts of d
Zinc Oxide (ZnO) is considered as one of the best materials already used as a window layer in solar cells due to its antireflective capability. The ZnO/MgF2 bilayer thin film is more efficient as antireflective coating. In this work, ZnO and ZnO/MgF2 thin films were deposited on glass substrate using pulsed laser deposition and thermal evaporation deposition methods. The optical measurements indicated that ZnO thin layer has an energy gap of (3.02 eV) while ZnO/MgF2 bilayer gives rise to an increase in the energy gap. ZnO/MgF2 bilayer shows a high energy gap (3.77 eV) with low reflectance (1.1-10 %) and refractive index (1.9) leading to high transmittance, this bilayer could be a good candidate optical material to improve the performance
... Show MoreAt a temperature of 300 K, a prepared thin film of Ag doped with different ratios of CdO (0.1, 0.3, 0.5) % were observed using pulse laser deposition (PLD). The laser, an Nd:YAG in ?=1064 nm, used a pulse, constant energy of 600 mJ ,with a repetition rate of 6 Hz and 400 pulses. The effect of CdO on the structural and optical properties of these films was studied. The structural tests showed that these films are of a polycrystalline structure with a preferred orientation in the (002) direction for Ag. The grain size is positively correlated with the concentration of CdO. The optical properties of the Ag :CdO thin film we observed included transmittance, absorption coefficient, and the energy gap in the wavelength range of 300-1100
... Show MoreTin dioxide (SnO2) were mixed with (TiO2 and CuO) with concentration ratio (50, 60, 70, 80 and 90) wt% films deposited on single crystal Si and glass substrates at (523 K) by spray pyrolysis technique from aqueous solutions containing tin (II) dichloride Dihydrate (SnCl2, 2H2O), dehydrate copper chloride (CuCl2.2H2O) and Titanium(III) chloride (TiCl3) with molarities (0.2 M). The results of electrical properties and analysis of gas sensing properties of films are presented in this report. Hall measurement showed that films were n-type converted to p- type as titanium and copper oxide added at (50) % ratio. The D.C conductivity measurements referred that there are two mechanisms responsible about the conductivity, hence it possess two act
... Show MoreCadmium Selenide (CdSe) thin films have been deposited on a glass substrate utilizing the plasma DC-sputtering method at room temperature at different deposition time in order to achieve different films thickness, and studied its sensitivity to the carbon monoxide CO gas which are show high response as the film thickness increases, the DC-conductivity and photoconductivity are also studied and which are increased too as the film thickness increases, that indicates the good semiconducting behavior at room temperature and light environments.
Pure SnSe thin film and doped with S at different percentage (0,3,5,7)% were deposited from alloy by thermal evaporation technique on glass substrate at room temperature with 400±20nm thickness .The influences of S dopant ratio on characterization of SnSe thin film Nano crystalline was investigated by using Atomic force microscopy(AFM), X-ray diffraction (XRD), energy dispersive spectroscopy (EDS), Hall Effect measurement, UV-Vis absorption spectroscopy to study morphological, structural, electrical and optical properties respectively .The XRD showed that all the films have polycrystalline in nature with orthorhombic structure, with preferred orientation along (111)plane .These films was manufactured of very fine crystalline size in the ra
... Show MoreTin dioxide doped silver oxide thin films with different x content (0, 0.03, 0.05, 0.07) have been prepared by pulse laser deposition technique (PLD) at room temperatures (RT). The effect of doping concentration on the structural and electrical properties of the films were studied. Atomic Force Measurement (AFM) measurements found that the average value of grain size for all films at RT decrease with increasing of AgO content. While an average roughness values increase with increasing x content. The electrical properties of these films were studied with different x content. The D.C conductivity for all films increases with increasing x content. Also, it found that activation energies decrease with increasing of AgO content for all films.
... Show MoreIn the present investigation, (NiO:WO3 ) thin films were deposited at RT onto glass substrates using PLD technique employing focused Nd:YAG laser beam at 600 mJ with a frequency second radiation at 1064 nm (pulse width 9 ns) repetition frequency (6 Hz), for 400 laser pulses incident on the target surface .The structural, morphological and optical properties of the films doped with different concentration of Au content (0.03, 0.05, and 0.07) were examined with X-ray diffractometer(XRD), Atomic Force Microscope(AFM) , UV–Vis spectrophotometer . The results show that the films were amorphous with small peaks appearing when doped with AuNPs . The XRD peaks of the deposited NiO:WO3 were enhanced with increasing t
... Show MorePolycrystalline Indium oxide (In2O3) and Indium oxide-zinc oxide (IZO) thin films mixed with 10% ZnO content were prepared by spray-pyrolysis technique at relatively low substrate temperature (150 ˚C).Field emission scanning electron microscope (FE-SEM) shows that the nanostructure at 10% ZnO content has pyramid like structure. The hall effect measurements show that the prepared samples have n-type charge carriers .The films were examined as gas sensor against H2S gas at different operating temperatures (200, 250 and 300) oC, and it was found that the IZO sample a good sensitivity to H2S gas ~ 572 % at operating temperature 200 oC, with relatively fast response time of 19 s and recovery time of 17
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