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 MoreIn this study, tin oxide (SnO2) and mixed with cadmium oxide (CdO) with concentration ratio of (5, 10, 15, 20)% films were deposited by spray pyrolysis technique onto glass substrates at 300ºC temperature. The structure of the SnO2:CdO mixed films have polycrystalline structure with (110) and (101) preferential orientations. Atomic force microscopy (AFM) show the films are displayed granular structure. It was found that the grain size increases with increasing of mixed concentration ratio. The transmittance in visible and NIR region was estimated for SnO2:CdO mixed films. Direct optical band gap was estimated for SnO2 and SnO2 mixed CdO and show a decrease in the energy gap with increasing mixing ratio. From Hall measurement, it was fou
... Show MoreIn the present article, Nano crystalline SnS and SnS:3% Bi thin films were fabricated using thermal
evaporation with 400±20 nm thickness at room temperature at a rate deposition rate of 0.5 ±0.01nm
/sec then annealing for one hour at 573 K for photovoltaic application. The prepared samples were
characterized in order to investigate the structural, electrical, morphological, and optical properties
using diverse techniques. XRD and SEM were recorded to investigate the effect of doping and
annealing on structural and morphological possessions, respectively. XRD showed an SnS phase
with polycrystalline and appeared to form an orthorhombic structure, with the distinguish trend
along the (111) grade,
SnO2 thin films of different two thicknesses were prepared an glass substrate by DC magnetron sputtering. The crystal structure and orientation of the films were investigated by XRD patterns. All the deposited films are polycrystalline. The grain size was calculated as 25.35, 28.8 nm. Morphological and compositions of the films were performed by SEM and EDX analyses respectively. The films appeared compact and rougher surface in nature. The allowed direct band gap was evaluated as 3.85 eV, and other optical constants such as refractive index, extinction coefficient, real and imaginary parts of dielectric constants were determined from transmittance spectrum in the wavelength range (300-900) nm and also analyzed.
A simple, inexpensive, and home–built electrostatic spray deposition (ESD) system with stable cone-jet mode was used to obtain nickel oxide (NiO) thin films on glass substrates kept at temperature of 400°C. The primary precursor solution of 0.1 M concentration hydrated nickel chloride dissolved in isopropyl alcohol. The structural, optical and electrical parameters were studied. The optical absorbance spectra for the studied samples showed its maximum around 280 nm. On the other hand, thickness interferometry measurements on the tested samples showed that film thickness was around 400 nm. The optical energy gap of the prepared NiO samples was determined to be 3.75 eV and the maximum value of refractive index was determined to be 2.1 a
... Show MoreCadmium sulfide (CdS) nanocrystalline thin films are prepared onto ITO-glass and Si(111) substrates by chemical bath deposition method. The scanning electron microscope images showed that the CdS thin film onto Si substrate is more homogenous without vacancies. The XRD patterns of the CdS nanocrystalline thin film confirm that they have polycrystalline with cubic phase. Room temperature photoluminescence (PL) spectrum of the CdS nanocrystalline thin films shows emission band located at 502nm for CdS/Si sample while the CdS/ITO-glass thin films shows a broad emission band peaked at 505nm. The Raman spectra of CdS nanocrystalline thin films prepared onto Si and ITO-glass substrates contain two main peaks which are corresponding to the firs
... Show More(Sb2S3)1-xSnx thin films with different concentrations (0, 0.05 and
0.15) and thicknesses (300,500 and 700nm) have been deposited by
single source vacuum thermal evaporation onto glass substrates at
ambient temperature to study the effect of tin content, thickness and
on its structural morphology, and electrical properties. AFM study
revealed that microstructure parameters such as crystallite size, and
roughness found to depend upon deposition conditions. The DC
conductivity of the vacuum evaporated (Sb2S3)1-x Snx thin films was
measured in the temperature range (293-473)K and was found to
increase on order of magnitude with
Diamond-like carbon, amorphous hydrogenated films forms of carbon, were pretreated from cyclohexane (C6H12) liquid using plasma jet which operates with alternating voltage 7.5kv and frequency 28kHz. The plasma Separates molecules of cyclohexane and Transform it into carbon nanoparticles. The effect of argon flow rate (0.5, 1 and 1.5 L/min) on the optical and chemical bonding properties of the films were investigated. These films were characterized by UV-Visible spectrophotometer, X-ray diffractometer (XRD) Raman spectroscopy and scanning electron microscopy (SEM). The main absorption appears around 296, 299 and 309nm at the three flow rate of argon gas. The value of the optical energy gap is 3.37, 3.55 and 3.68 eV at a different flow rate o
... Show Morea-Ge: As thin films have prepared by thermal evaporation teclmique, then they were annealing at various temperatures within the
range (373-473) K. The result of X-ray di ffraction spectrum was showing that all the specimens remained in amorphous structure before and after annealing process. This paper studied the effect of annealing temperature as a function of wavelength on the optical energy gap and optical constants for the a-Ge:As thin films . Results have showed that there was an increasing in the optical energy gap
{Egopt) values with the in ,;rcasing of the annealing temperatures within
... Show More