Structural and optical properties of CdxZn(1 −x)Te thin films

✍ Scribed by H. S. Soliman; F. M. Allam; A. A. El-Shazly

• Publisher: Springer US
• Year: 1996
• Tongue: English
• Weight: 443 KB
• Volume: 7
• Category: Article
• ISSN: 0957-4522
• DOI: 10.1007/bf00133121

✦ Synopsis

Seven CdxZn(1-x) Te solid solutions with x=0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9 and 1.0 were synthesized by fusing stoichiometric amounts of CdTe and ZnTe constituents in silica tubes. Each composition was used in the preparation of a group of thin films of different thicknesses. Structural investigation of the obtained films indicates they have a polycrystalline structure with predominant diffraction lines corresponding to (1 1 1)(22 0) and (3 1 1) reflecting planes, which can be attributed to the characteristics of growth with the (1 1 1) plane.

The optical constants (the refractive index n, the absorption index k, and the absorption coefficient ~) of CdxZn(1-~Te thin films were determined in the spectral range 500-2000 nm. At certain wavelengths it was found that the refractive index, n, increases with increasing molar fraction, x. It was also found that plots of c~ 2 (hv) and c~ 1/2 (hv) yield straight lines, corresponding to direct and indirect allowed transitions respectively obeying the following two equations: E d = 1.583 + 0.277x+ 0.197x 2 E~na= 1.281 +0.11 lx+ 0.302x 2