Document Details

Document Type : Article In Journal 
Document Title :
Effects of annealing temperatures on optical and electrical properties of vacuum evaporated Ga15Se77In8 chalcogenide thin films
Effects of annealing temperatures on optical and electrical properties of vacuum evaporated Ga15Se77In8 chalcogenide thin films
 
Subject : Physics 
Document Language : English 
Abstract : The optical constants (absorption coefficient, optical band gap, refractive index, extinction coefficient, real and imaginary parts of dielectric constants) of amorphous and thermally annealed thin films of Ga 15Se77In8 chalcogenide glasses with thickness 4000 have been investigated from absorption and reflection spectra as a function of photon energy in the wave length region 400-800 nm. Thin films of Ga 15Se77In8 chalcogenide glasses were thermally annealed for 2 h at three different annealing temperatures 333 K, 348 K and 363 K, which are in between the glass transition and crystallization temperature of Ga15Se77In8 glasses. Analysis of the optical absorption data shows that the rule of non-direct transitions predominates. It was found that the optical band gap decreases with increasing annealing temperature. It has been observed that the value of absorption coefficient and extinction coefficient increases while the values of refractive index decrease with increasing annealing temperature. The decrease in optical band gap is explained on the basis of the change in nature of films, from amorphous to crystalline state. The dc conductivity of amorphous and thermally annealed thin films of Ga15Se77In8 chalcogenide glasses is also reported for the temperature range 298-393 K. It has been observed that the conduction is due to thermally assisted tunneling of the carriers in the localized states near the band edges. The dc conductivity was observed to increase with the corresponding decrease in activation energy on increasing annealing temperature in the present system. These results were analyzed in terms of the Davis-Mott model. 
ISSN : 0042-207X 
Journal Name : Vacuum 
Volume : 85 
Issue Number : 9 
Publishing Year : 1432 AH
2011 AD 
Article Type : Article 
Added Date : Tuesday, June 12, 2012 

Researchers

Researcher Name (Arabic)Researcher Name (English)Researcher TypeDr GradeEmail
فيصل عبدالعزيز العقلAl-Agel, Faisal AResearcherDoctoratefagel@kau.edu.sa

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