الفهرس 
1.1 IntroductionOnly 14 pages are availabe for public view
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Abstract
The samples Se82.05 S5.15 Te12.8 and Se87.41S4.03In8.56 were prepared by using melt Quenching technique. The X-ray diffraction and the SEM micrographs ensure the amorphous nature of obtained the samples as powder and thin films.
The light transmission (T) and reflection(R) were non-linear as function of wavelength during the wavelength range 200-2500 nm
The same behavior was revealed for the refractive index(n),extinction coefficient(K) and absorption coefficient (α).the optical energy gap(Ego)was calculated and found to be 1.7 and 1.8 eV for Se82.05 S5.15 Te12.8 and Se87.41S4.03In8.56 respectively.
The optical parameters illustrate that these two samples can be used as ultraviolet absorber and transparent window during the visible and IR regions. The laser induced photocurrent show theses samples are photosensitive for the both laser irradiation and medium temperature.
The photodarkening phenomena was revealed as transmission peaks and reflection peaks were shift toward longer wavelength for both samples as laser exposure time increases.
Photobleaching was also detected as the transmission and reflection peaks were shift toward short wavelength at some exposure time. The optical band gap (Ego) was decreases as laser exposure time increase. The change of T,R and Ego with laser exposure time has been used as a measure for the amorphous-crystalline transformation.
Also, the change of the electric resistance(r) under the laser exposure time was used as a measure of amorphous-crystalline transformation.
The crystalline kinetic was following by T,R , Ego and r as function of laser exposure time using Avarmi,s equation.
The rate of crystallization (K) and exponent factor (n) of Avarmi,s equation were calculated. The value of (K) was constant for every sample and the constant (n) was a fraction value around unity. This means that, the crystal growth was in one- dimensional. The energy of crystallization was calculated from change of the electrical resistance with laser exposure time and found to be 10.226 K.cal/mole and 17.355 K.cal/mole for Se82.05 S5.15 Te12.8 and Se87.41S4.03In8.56 respectively. This result confirm that the phase transformation process for Se87.41S4.03In8.56 was slower than of Se82.05 S5.15 Te12.8. the X-ray diffraction was used to follow the phase transformation process and the detected crystalline phases were Se7.68 Te0.32 , Se S, S Te, Se and S e S 2 for sample Se82.05 S5.15 Te12.8 and were Se S10, Β- Se3 In2 , Se2.4 S 0.6 In 2 and S In for the sample Se87.41S4.03In8.56 .Also , the SEM micrograph confirm same results.