Original scientific paper
Crystal structure and optical properties of quaternary systems of Bi-Sb-Te-Se
A. M. Abou El Soud
; Solid State Physics Laboratory, National Research Centre, Dokki, Cairo, Egypt
B. S. Farag
; Solid State Physics Laboratory, National Research Centre, Dokki, Cairo, Egypt
I. S. Ahmed Farag
; Solid State Physics Laboratory, National Research Centre, Dokki, Cairo, Egypt
S. A. Gad
; Solid State Physics Laboratory, National Research Centre, Dokki, Cairo, Egypt
H. A. Zayed
; Physics Department, Girls College for Art, Science and Education, Shams University, Cairo, Egypt
Abstract
The quaternary systems of Bi-Sb-Te-Se were synthesized by direct fusion technique. Thin films of these compounds were prepared by thermal evaporation under vacuum of 10−4 Pa. The structural properties of these compounds in powder and thin film forms were investigated by X-ray diffraction. The optical constants (absorption coefficient and band gap) of the thin films were determined by measurements of IR absorbance in the region 2.5 – 10 µm. Analysis of the optical absorption spectra revealed the existence of two direct energy gaps.
Keywords
Bi-Sb-Te-Se thin films; structural properties; IR absorption; direct energy gaps
Hrčak ID:
302526
URI
Publication date:
2.3.2008.
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