In this study, the ZnTe thin films were deposited on a glass substrate at a thickness of 400nm using vacuum evaporation technique (2×10-5mbar) at RT. Electrical conductivity and Hall effect measurements have been investigated as a function of variation of the doping ratios (3,5,7%) of the Cu element on the thin ZnTe films. The temperature range of (25-200°C) is to record the electrical conductivity values. The results of the films have two types of transport mechanisms of free carriers with two values of activation energy (Ea1, Ea2), expect 3% Cu. The activation energy (Ea1) increased from 29meV to 157meV before and after doping (Cu at 5%) respectively. The results of Hall effect measurements of ZnTe , ZnTe:Cu films show that all films were (p-type), the carrier concentration (1.1×1020 m-3) , Hall mobility (0.464m2/V.s) for pure ZnTe film, increases the carrier concentration (6.3×1021m-3) Hall mobility (2m2/V.s) for doping (Cu at 3%) film, but decreases by increasing Cu concentration.
ABSTRACT Porous silicon has been produced in this work by photochemical etching process (PC). The irradiation has been achieved using ordinary light source (150250 W) power and (875 nm) wavelength. The influence of various irradiation times and HF concentration on porosity of PSi material was investigated by depending on gravimetric measurements. The I-V and C-V characteristics for CdS/PSi structure have been investigated in this work too.
In this research the effect of laser energy by using argon gas on the some physical properties of semiconductor film of TiO2, was studied used Q-Switch Nd:YAG laser in different energies (600-1000) mJ with temperature 100 0C for glass substrate under vacuum nearly 10-3 - - , and by AFM test the roughness of films increased when the energy of laser increased too. The values of roughness between (6.77-13) nm, therefore the thicknesses increased to change from (34.88 - 165.48) nm, so the absorption of film increased because of the thickness of the film increased and we can get the optical energy gap between (3.6-3.9) eV.
This research aims at studying each of the cold and hot thermal wavelengths affecting
Iraq for a minimum climatic course of 11 years beginning from 1992 till 2002. Three stations
were selected including the parts of Iraq surface: Mosul, Baghdad and Basrah.
The wave days were also connected with the related climatic elements represented by
the wind direction and speeds and the relative humidity. It was shown that Iraq is affected by
the rates of hot thermal wave lengths greatly compared to the rates of cold wavelengths. The
results suggested that the highest rate of hot and cold wavelengths recorded over Basra station
was (3.5) days for the cold and (5) days for the hot. While the lowest rates was at Mosul
station
This research studied the effects of modified BaTiO3 (BT) nanoparticles with coupling agent γ-APS (0.5wt. %) on the tensile and thermal conductivity of epoxy nanocomposites with respect to content (0.25, 0.5, 0.75, 1, 3 and 5wt. %). Multiwall carbon nanotubes (MWCNTs) at different concentration (0.2, 0.4, 0.8 and 1 wt. %) were added to the BaTiO3/epoxy nanocomposites. The influence of MWCNTs on the tensile properties and thermal conductivity was investigated. The tensile strength and Young’s modulus of BaTiO3/epoxy nanocomposites film were increased at up to 3 wt. % of added BT, but adding BT at more than 3 wt.% decreased the strength of epoxy. The tensile strength was increased with incre
... Show MoreIn this paper, Al and Cu Plasmas that produced by pulsed Nd:YAG laser with fundamental wave length with a pulse duration of 6 nS focused onto Al and Cu targets in atmospheric air are investigated spectroscopically. The influence of pulse laser energy on the some Al and Cu plasmas characteristics was diagnosed by using optical emission spectroscopy for the wavelength range 320-740 nm. The results observed that the increase of pulse laser energy causes to increase all plasma characteristics of both plasmas under study and shown increasing of the emission line intensity. The appearance of the atomic and ionic emission lines of an element in the emission spectrum depends on the ionization energy of target atoms. The plasma characteristics ar
... Show MoreA hand lay-up method was used to prepare Epoxy/ metal composites. Epoxy resin (EP) was used as a matrix with metal particles (Al, Cu, and Fe) as fillers.
The preparation method includes preparing square panels of composites with different weight percentage of fillers (10, 20, 30, 40, and 50%). Standard specimens (88mm in diameter) for thermal conductivity tests were prepared to measure thermal conductivity kexp.The result of experimental thermal conductivity kexp, for EP/metal composites show that, kexp increase with increasing weight percentage, For EP/ Al and EP/Cu composites, and it have have maximum values of 0.33 and 0.35 W/m.K, respectively. While kexp for EP/ Fe composite show slight increase with maximum value of 0.186 W/m.K.
Tin oxide films (SnO2) of thickness (1 ?m) are prepared on glass substrate by post oxidation of metal films technique. Films were irradiated with Nd:YAG double frequency laser of wavelength (532 nm) pulses of three energies (100, 500, 1000) mJ. The optical absorption, transmission, reflectance, refractive index and optical conductivity of these films are investigated in the UV-Vis region (200-900) nm. It was found that the average transmittance of the films is around (80%) at wavelength (550 nm) and showed high transmission (? 90 %) in the visible and near infrared region. The absorption edge shifts towards higher energies, which is due to the Moss-Burstien effect and it lies at (4 eV). The optical band gap increased with increasing of ene
... Show MoreIn the current study, CuAl0.7In0.3Te2 thin films with 400 nm thickness were deposited on glass substrates using thermal evaporation technique. The films were annealed at various annealing temperatures of (473,573,673 and 773) K. Furthermore, the films were characterized by X-ray Diffraction spectroscopy (XRD), field emission scanning electron microscopy (FESEM), atomic force microscopy (AFM), and Ultra violet-visible (UV–vis). XRD patterns confirm that the films exhibit chalcopyrite structure and the predominant diffraction peak is oriented at (112). The grain size and surface roughness of the annealed films have been reported. Optical properties for the synthesized films including, absorbance, transmittance, dielectric constant, and refr
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