The optical constants (absorption coecient, refractive index, extention coecient, real and imaginary part of dielectric con-stant) have been studied for a-Se80Te20. xPbx (wherex = 0,2,6,10) thin lms as a function of photon energy in the wave length ra...
The optical constants (absorption coecient, refractive index, extention coecient, real and imaginary part of dielectric con-stant) have been studied for a-Se80Te20. xPbx (wherex = 0,2,6,10) thin lms as a function of photon energy in the wave length range(5001000nm). It has been found that the optical band gap increases while the refractive index and the extinction coecient (k)decreases on incorporation of lead in SeTe system. The value of absorption coecient (a) and the extinction coecient (k)increases, while the value of refractive index (n) decreases with incident photon energy. The results are interpreted in terms ofthe change in concentration of localized states due to the shift in fermi level..