This work focuses on the preparation of pure nanocrystalline SnO2 and SnO2:Cu thin films on cleaned glass substrates utilizing a sol-gel spin coating and chemical bath deposition (CBD) procedures. The primary aim of this study is to investigate the possible use of these thin films in the context of gas sensor applications. The films underwent annealing in an air environment at a temperature of 500 ◦C for duration of 60 minutes. The thickness of the film that was deposited may be estimated to be around 300 nm. The investigation included an examination of the structural, optical, electrical, and sensing characteristics, which were explored across various preparation circumstances, specifically focusing on varied concentrations of Cu-doping (2, 4, and 6 wt.%). The deposited films were analyzed by several techniques, including X-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM), and optical absorption spectroscopy. The films generated by the spin coating method had a tetragonal rutile structure, while the films created via the chemical bath deposition (CBD) technique displayed both tetragonal rutile and orthorhombic structures. The spin coating technique was used to make films of several weight percentages (0, 2, 4, and 6 wt.%). The resulting crystallite sizes were examined and found to be 23 nm, 18 nm, 14 nm, and 10.5 nm, respectively. Similarly, films made using the chemical bath deposition (CBD) method exhibited crystallite sizes of 22, 13.9, 9.3, and 8.15 nm, respectively. The obtained findings from atomic force microscopy (AFM) and scanning electron microscopy (SEM) analyses indicate a consistent trend whereby, as the concentration of Cu-doped material rises, there is a decrease in the average grain size. The transmittance and absorbance spectra were examined within the wavelength range of 300 to 1000 nm. The films generated by both approaches exhibit a significant level of light transmission throughout the visible spectrum. The bandgap energy of spin coating and CBD films decreases with increasing Cu-doped concentrations; the values were (3.88, 3.8, 3.68, and 3.63) eV and (3.8, 3.78, 3.66, and 3.55) eV, respectively. The electrical characteristics of the films include direct current (DC) electrical conductivity, which indicates the presence of two activation energies, Ea1 and Ea2. These activation energies exhibit an upward trend when the concentration of Cu doping is increased. The films were examined for their ability to detect carbon monoxide (CO) gas at a concentration of about 50 ppm at normal room temperature conditions. The sensitivity of the films to carbon monoxide (CO) gas was assessed at various time intervals and temperatures. The results indicated that the film generated using spin coating exhibited a notably high sensitivity at a temperature of 200 °C, while the film prepared using the chemical bath deposition (CBD) approach had heightened sensitivity at a temperature of 150 °C. Keywords: Spin coating, SnO2 thin films, CBD, AFM, XRD, gas sensor.
CuInSe2 (CIS)thin films have been prepared by use vacuum thermal evaporation technique, of 750 nm thickness, with rate of deposition 1.8±0.1 nm/sec on glass substrate at room temperature and pressure (10-5) mbar. Heat treatment has been carried out in the range (400-600) K for all samples. The optical properties of the CIS thin films are been studied such as (absorption coefficient, refractive index, extinction coefficient, real and imaginary dielectric constant)by determined using Measurement absorption and transmission spectra. Results showed that through the optical constants we can made to control it is wide applications as an optoelectronic devices and photovoltaic applications.
In this work the effect of annealing temperature on the structure and the electrical properties of Bi thin films was studied, the Bi films were deposited on glass substrates at room temperature by thermal evaporation technique with thickness (0.4 µm) and rate of deposition equal to 6.66Å/sec, all samples are annealed in a vacuum for one hour. The X-ray diffraction analysis shows that the prepared samples are polycrystalline and it exhibits hexagonal structure. The electrical properties of these films were studied with different annealing temperatures, the d.c conductivity for films decreases from 16.42 ? 10-2 at 343K to 10.11?10-2 (?.cm)-1 at 363K. The electrical activation energies Ea1 and Ea2 increase from 0.031 to 0.049eV and
... Show MoreCadmium 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
... Show MoreIn this research ,Undoped Nio and 1%Li doped Nio thin films were deposited utilizing chemical spray pyrolysis on the glass substrates heated (450C). The effects of non-thermal plasma on the structural and optical properties were studied. XRD measurement shows that Nio and Nio:1%Li films were found to be polycrystalline and have cubic structure with a preferred orientation (111). Decreased crystal size after exposure especially at (7) sec. AFM data indicate that the surface roughness average and (RMS) values of the prepared doped films are increasing after exposure to plasma, the transmittance increases after doped samples exposure to plasma, it was found that the energy gap value decreased when doped samples exposure to plasma, also, thickn
... Show MoreBackground: Human leukocyte antigen-G (HLA-G)and Toll-like receptor-9 (TLR-9)play a role in the regulation of autoimmune diseases and inflammatory processes. Aim of the study: To detect the HLA-G + 3142G > C gene polymorphism that associated with the susceptibility to SLE patients and associated with Hepatitis B infection and TLR-9 serum level. Patients and methods: This study was done on 75 SLE patients and 75 healthy control groups. Genotyping of HLA-G + 3142G > C were detected by PCR and PCR-RFLP methods. In addition to the estimation of Hepatitis B surface (HBs)antigen status by immunochromatography technique and TLR-9 serum level by ELISA technique. Results: The HLA-G + 3142G > C gene polymorphism between the SLE patients and controls
... Show MoreIn this work, Titanium oxide thin films doped with different concentration of CuO (0,5,10, 15,20) %wt were prepared by pulse laser deposition(PLD) technique on glass substrates at room temperature with constant deposition parameter such as : pulse (Nd:YAG), laser with λ=1064 nm, constant energy 800 mJ , repetition rate 6 Hz and No. of pulse (500). The structure , optical and electrical properties were studied . The results of X-ray diffraction( XRD) confirmed that the film grown by this technique have good crystalline tetragonal mixed anatase and rutile phase structure, The preferred orientation was along (110) direction for Rutile phase. The optical properties of the films were studied by UV-VIS spectrum in the range of (360-1100)
... Show MoreIn this study, SnS thin films were deposited onto glass substrate by thermal evaporation technique at 300K temperature. The SnS films have been prepared with different thicknesses (100,200 &300) nm. The crystallographic analysis, film thickness, electrical conductivity, carrier concentration, and carrier mobility were characterized. Measurements showed that depending on film thickness. The D.C. conductivity increased with increase in film thickness from 3.720x10-5 (Ω.cm)-1 for 100 nm thickness to 9.442x10-4 (Ω.cm)-1 for 300 nm thicknesses, and the behavior of activation energies, hall mobility, and carrier concentration were also studied.