Structure, optical and electrical properties of Ge30Sb10Se60 thin films

• Published in: Physica. B, Condensed matter Condensed matter, 2008-05, Vol.403 (10-11), p.1848-1853
• Main Authors: ALY, K. A, ABOUSEHLY, A. M, OSMAN, M. A, OTHMAN, A. A
• Format: Article
• Language: English
• Subjects: Amorphous semiconductors; glasses; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Electrical properties of specific thin films; Electronic structure and electrical properties of surfaces, interfaces, thin films and low-dimensional structures; Exact sciences and technology; Optical properties and condensed-matter spectroscopy and other interactions of matter with particles and radiation; Optical properties of specific thin films; Physics
• ISSN: 0921-4526; 1873-2135
• DOI: 10.1016/j.physb.2007.10.019

Amorphous Ge30Sb10Se60 chalcogenide thin films were prepared onto cleaned glass substrates using thermal evaporation technique. The structure of the as-prepared films was confirmed to be amorphous using X-ray diffraction. The optical absorption coefficient () for the as-deposited films was calculated by using reflectance and transmittance measurements in the wavelength range 400-900 nm. The optical constants (refractive index (n) and the extinction coefficient (k)) were controlled by Murman's exact equations. The effects of annealing temperature in the temperature range 300-658 K on the optical and electrical properties of the as-prepared Ge30Sb10Se60 thin films were discussed in details. It was found that both the optical band gap and the activation energy for electrical conduction DeltaEdc increase with increasing the annealing temperature up to the glass transition temperature (Tg), followed by a remarkable decrease with the increase of annealing temperature above Tg. The obtained results were interpreted on the basis of amorphous-crystalline transformations.