Cu2ZnSnS4 (CZTS) thin films were prepared by directly sputtering
Cu (In,Ga)Se2 quaternary target consisting of (Cu: 25%, Zn: 12.5%, Sn; 12.5%
and S: 50%). The composition and structure of CZTS layers have been
investigated after annealing at 200 0C, 350 0C and 500 0C under vacuum. The
results show that recrystallization of the CZTS thin film occurs and increasing
the grain size with a preferred orientation in the (112) direction was obtained. The
Raman spectra showed the existence of crystalline CZTS phase after annealing.
Optical transmission spectra were recorded within the range 300-900 nm. The
energy band gap (Eg) of the CZTS thin films was calculated before and after
annealing from the transmittance spectra using Beer-Lambert’s law. Results show
that Eg is dependent on the annealing temperature. The optical band gap of CZTS
also varied from 1.57 eV to 1.31 eV with increase in the annealing temperature
from 200 0C min to 500 0C. تفاصيل المقالة

Thin layer of titanium dioxide has been deposited on a glass sheet using RF magnetron sputtering under different preparation conditions. Phase, lattice parameters, optical features and morphology were investigated under different laboratory conditions in different thicknesses by using XRD, spectrophotometry and atomic force microscopic (AFM), within the visible spectrum range. Also, the lattice structure, in most cases, is tetragonal or a combination of tetragonal and orthorhombic. The band gap energy for each layer was measured using Tauc’s Plot. It was observed that the edge of absorption is reduced following an increase in thickness except for a thickness of 75 nm. By increasing the pressure, the band gap energy of the layers or the edge of absorption increases except for 0.04 mbar. By increasing the power, the band gap energy of the layers will change resulting in an increasing-decreasing trend in the edge of absorption, which can be the outcome of changes in the lattice formation. Nevertheless, it is obvious that the band gap energy, phase, lattice parameter and morphology is totally dependent on the laboratory conditions of making layers. تفاصيل المقالة

Abstract: In this paper, combining the Maxwell equations with the electron balance
equation, we obtain the inverse braking radiation absorption coefficient in a laser fusion
corona plasma. For a fixed plasma temperature, variations of the absorption coefficient
versus the penetration depth into the plasma are illustrated numerically for different
values of laser wavelength. It is shown that, by increasing the skin depth of the laser
into the plasma, the absorption coefficient increases and tends to asymptotic value one.
The effect of plasma temperature on the absorption coefficient has also been
investigated. In addition, the fraction of absorbed energy for resonance absorption is
studied analytically and illustrated numerically. Moreover, the fractional absorption for
different laser wavelengths as well as different values of incident angle is illustrated. It
can be seen that, the maximum value of the absorption coefficient is independent of the
laser wavelength and is about 0.6 for all the wavelengths. تفاصيل المقالة

In this paper, we employed Raman spectroscopy to
investigate Indium sulfide thin layer films deposited on
glass substrates using the PVD method. The results showed
that the bandwidth and Raman shift of different In2S3 thin
films depended on the annealing temperature. In addition,
the crystallization stage from tetragonal to cubic occurred
at the excessive temperature range of 350-400 °C. The
Raman spectroscopy of the In2S3 thin films before
annealing and at 300 °C indicated the existence of β- In2S3
at 70, 166 and 281 cm-1 in the active modes of the spectra.
New modes that were related to α-In2S3 appeared at 126,
244, and 266 cm-1 after thermal treatment at 400 °C for 30
and 60 min. Our results are in agreement with the phase
transitions observed from the XRD analysis of In2S3 thin
films. There are few reports about the Raman spectroscopy
of In2S3 thin layer films deposited using vacuum thermal
evaporation. In the present paper, the Raman spectra of
In2S3 thin films with different thicknesses as well as the
effects of temperature on their depositions in vacuum were
examined. تفاصيل المقالة