Effect of cadmium addition on the optical constants of thermally evaporated amorphous Se-S-Cd thin films

作者：Khan Shamshad A^*; Al Hazmi F S; Al Heniti S; Faidah A S; Al Ghamdi A A

来源：Current Applied Physics, 2010, 10(1): 145-152.

DOI：10.1016/j.cap.2009.05.010

• Amorphous semiconductor
• Glasses
• Optical band gap
• Optical constants
• Absorption

Se(75)S(25-x)Cd(x) is a promising ternary material, which has received considerable attention due to its applications in the fabrication of various solid state devices. These have distinct advantages, large packing density, mass replication, fast data rate, high signal-to-noise ratio and high immunity to defects. Measurements of optical constants (absorption coefficient, refractive index, extinction coefficient, real and imaginary part of the dielectric constant) have been made on Se(75)S(25-x)Cd(x) (where x = 0, 2, 4, 6 and 8) thin films of thickness 3000 angstrom as a function of photon energy in the wave length range 4001000 nm. It has been found that the optical band gap and extinction coefficient increases while the value refractive index decreases on incorporation of cadmium in Se-S system. The results are interpreted in terms of the change in concentration of localized states due to the shift in Fermi level. Due to the large absorption coefficient and compositional dependence of reflectance, these materials may be suitable for optical disk material.

• 出版日期2010-1