scholarly journals Preparation and Characterization of In2O3-CuO Nanocomposite Thin Films as NH3 Gas Sensor

2021 ◽  
pp. 2204-2212
Author(s):  
Abd alhameed A. Hameed ◽  
Hamid S. AL-Jumaili

      An NH3 gas sensor was prepared from nanocomposite films of indium oxide-copper oxide mixtures with ratios of 0 , 10 , and 20 Vol % of copper oxide. The films were deposited on a glass substrate using chemical spray pyrolysis method (CSP) at 400oC. The structural properties were studied by using X-ray diffraction (XRD) and atomic force microscopy ( AFM). The structural results showed that the prepared thin films are polycrystalline, with nano grain size. By mixing copper oxide with indium oxide, the grain size of the prepared thin films was decreased and the surface roughness was increased. The UV-Visible spectrometer analysis showed that the prepared thin films have high transmittance. This transmittance was decreased by mixing copper oxide with indium oxide. The direct optical energy gap ranged 3.5 - 3 eV, which was decreased with increasing copper oxide concentration. The sensitivity of the prepared gas sensor was measured towards NH3 gas at a concentration of 71ppm with operating temperatures of 100, 150, 200, 250 and 30) oC, according to the change of sensor resistance. This sensitivity of the mixture oxides showed a value of about nine times greater than that of individual indium oxide thin films. The results of the optimum gas sensor properties demonstrated a sensitivity value of 75.06%, response time of 10s, and recovery time of 11 s, at a mixing ratio of 20% of copper oxide and an operating temperature of 200oC.

2017 ◽  
Vol 14 (1) ◽  
pp. 75-79
Author(s):  
Baghdad Science Journal

In this research Bi2S3 thin films have been prepared on glass substrates using chemical spray pyrolysis method at substrate temperature (300oC) and molarity (0.015) mol. Structural and optical properties of the thin films above have been studied; XRD analysis demonstrated that the Bi2S3 films are polycrystalline with (031) orientation and with Orthorhombic structure. The optical properties were studied using the spectral of the absorbance and transmission of films in wavelength ranging (300-1100) nm. The study showed that the films have high transmission within the range of the visible spectrum. Also absorption coefficient, extinction coefficient and the optical energy gap (Eg) was calculated, found that the film have direct energy gap equal to 2.8 eV.


Author(s):  
Muneer H. Jadduaa ◽  
Zainab Ali Harbi ◽  
Nadir F. Habubi

Thin films of CdO were prepared by chemical spray pyrolysis (CSP) . The effect of different temperature substrate (300,350,400,450 and 500) °C on some optical parameters has been studied . The transmittance and the optical energy gap were increased from (2.503-2.589) eV ,on the contrary of the rest parameters such as refractive index , real and imaginary parts of dielectric constant and Urbach energy which they were decreased as the substrate temperature increase.


2019 ◽  
Vol 27 (03) ◽  
pp. 1950124 ◽  
Author(s):  
MOHAMMED YARUB HANI ◽  
ADDNAN H. AL-AARAJIY ◽  
AHMED M. ABDUL-LETTIF

Nickel(II) phthalocyanine-tetrasulfonic acid tetrasodium salt (NiTsPc) thin films were deposited on glass substrates at different substrate temperatures ([Formula: see text]) by chemical spray pyrolysis (CSP) technique. The substrate temperature varied from 110∘C to 310∘C in 50∘C steps. The substrate surface temperature is the main parameter that determines the film morphology and properties of the thin films. The structural properties of the deposited NiTsPc thin films were investigated by X-ray diffraction (XRD) and from the obtained results, it was shown that depositing thin films using 210∘C as [Formula: see text] results in higher crystallinity. Atomic force microscope (AFM) was employed to obtain the surface topography and to calculate the roughness and grain size. The smoothest thin film surface was obtained when using at 160∘C, while the highest roughness was obtained at 310∘C. The optical properties were investigated by ultraviolet visible (UV-Vis) spectrophotometer and fluorescence spectrophotometer. From the absorption spectra recorded in the wavelength range 190–1100[Formula: see text]nm, two absorption bands were observed, which are known as Soret and Q-band. By observing the absorption spectrum, it can be concluded that the deposited thin films at 110∘C–310∘C have direct energy gap. From Tauc plot relation, the energy gap ([Formula: see text]) was calculated. The values of the energy gap were between 3.05 and 3.14[Formula: see text]eV. It was observed that different [Formula: see text] highly affects the structural and optical properties of the deposited thin films. The crystallinity, grain size, roughness and the optical properties were strongly affected by the different substrate temperatures.


2019 ◽  
Vol 14 (29) ◽  
pp. 191-197
Author(s):  
Awras H. Ajil

Nanocomposites of polymer material based on CdS as fillermaterial and poly methyl methacrylate (PMMA) as host matrix havebeen fabricated by chemical spray pyrolysis method on glasssubstrate. CdS particles synthesized by co-precipitation route usingcadimium chloride and thioacetamide as starting materials andammonium hydroxide as precipitating agent. The structure isexamined by X-ray diffraction (XRD), the resultant film hasamorphous structure. The optical energy gap is found to be (4.5,4.06) eV before and after CdS addition, respectively. Electricalactivation energy for CdS/PMMA has two regions with values of0.079 and 0.433 eV.


2009 ◽  
Vol 6 (3) ◽  
pp. 519-225
Author(s):  
Baghdad Science Journal

In this research we prepared CdS thin films by Spray pyrolysis method on a glass substrates and we study its structural , optical , electrical properties .The result of (X-Ray ) diffraction showed that all thin films have a polycrystalline structure , The relation of the transmission as a function of wavelength for the CdS films had been studied , The investigated of direct energy gap of the CdS its value is (2.83 eV). In Hall effect measurement of the CdS we find the charge carriers is p – type and Hall coefficient 1157.33(cm3/c) ,Hall mobility 6.77(cm2/v.s)


2019 ◽  
Vol 30 (1) ◽  
pp. 193
Author(s):  
Karrar Mahdi Saleh

In the present work, undoped CdS and doped with iron CdS:Fe+3 thin films have been prepared by chemical spray pyrolysis method on glass substrate with different temperature from cadmium nitrate solution with constant thickness(450 ± 5 nm), and study the effect of the percentage of doping with iron on optical properties of prepared films. The optical properties have been studied from transmittance and absorbance spectral within wavelengths range (380-900 nm). The results showed that all the prepared films has direct electronic transitions and optical energy gap between (2.31-2.44 eV). They also showed that the transmittance and optical energy gap of films prepared from nitrate solution increase with increasing of substrate temperature, then transmittance start downward with the continued increase in temperature (400, 450 oC), and a decrease in the optical energy gap with increasing doping percentage with iron.


Author(s):  
Reem Sami Ali

Thin films of bismuth oxide have been prepared utilizing vacuum evaporation. XRD anyalysis reveal that all the films were tetragonal polycrystalline structure with a preferred orientation along (002) plane. SEM images indicate that the grain size fall in the category of nanosize. AFM results assure that the nanonstructure behavior of thin films. Optical studies show that these films have a direct transition with optical energy gap equal to 2.5 eV.


Author(s):  
Sabah A. Salman ◽  
Ziad T. Khodair ◽  
Sahar J. Abed

Cobalt Ferrite CoFe2O4 thin films have been deposited by chemical spray pyrolysis method (CSP) on glass substrates at different substrate temperatures (300, 350, 400 and 450°C) with an interval of (50°C) using Cobalt Nitrate and Ferric Nitrate as Cobalt and Iron sources respectively, at thickness (400±20) nm. The effect of substrate temperatures change on the optical properties for all prepared films was studied. The optical properties for all the films were studied by recording the transmittance and absorbance spectrum in the range of (300-900) nm. The results showed decreases in transmittance and increases in absorbance with increasing the substrate temperatures. the optical energy gap for allowed direct electronic transition was calculated and it was found that decreases with increasesing the substrate temperatures (2.40-2.22 eV), the Urbach energy increases with increasesing the substrate temperatures and it is values range between (634.6-700.5) meV. The optical constants (absorption coefficient, refractive index, extinction coefficient, real and imaginary parts of dielectric constant and optical conductivity) as a function of photon energy for all prepared films were calculated.


2018 ◽  
Vol 34 (5) ◽  
pp. 2667-2670 ◽  
Author(s):  
Bhawna Sarwan ◽  
Aman Deep Acharya

To investigate the influence of Ag concentration on physical properties, the Zn1-xAgxO films were synthesized by chemical spray pyrolysis method. The crystallite size was found to decrease for low concentration of Ag then increase upto 50 nm with increase in Ag content. AFM measurement implies that the roughness and grain size increased due to coalescence of petite grains into larger size. In optical measurement, band gap is found to be decreased with increase in filler concentration.


Author(s):  
Nadir F. Habubi ◽  
Ziad M. Abood ◽  
Ahmed N. Algamel

Thin films of nanostructured SnO2 with different molariteswere prepared by chemical spray pyrolysis technique. XRD analysis reveals that all the films were tetragonal polycrystalline with a preferred orientation along (110) plane. AFM measurements indicate that the value of the grain size for 0.05 M, 0.1 M and 0.15 M were 111nm, 78 nm and 58 nm respectively. SEM micrograph proved the existence of small cracks on the film surface, EDS confirmed the composition percentage ratio of Sn and O­2 and no trace of impurities could be detected. PL spectra gives the indication about optical energy gap and the effect of concentration on it which appeared as a blue shift. The transmittance was studied for the deposited thin films, identifying that the transmittance decreases by the increase in molarity. The value of the optical energy gap of the deposited thin films was increased upon increasing molar concentration due o quantum confinement effect. The Urbach energy was also studied, their values decrease as the molar concentration increase.


Sign in / Sign up

Export Citation Format

Share Document