Physics Department, Faculty of Education, Ain Shams University, Rorxy Square, Cairo 11757, Egypt
Optical properties of 4-tricyanovinyl-N, N-diethylaniline thin films were investigated using spectrophotometric measurement of transmittance and reflectance at normal incidence of light in the wavelength range of 200–2500 nm. The optical constants (refractive index, n, and absorption index, k) were calculated using a computer program based on Murmann's exact equations. The calculated optical constants are independent of the film thickness and their values are decreased by annealing temperature. The optical dispersion parameters have been analysed by single oscillator model. The type of transition in as-deposited films is indirect allowed with a value of energy gap equals to 1.45 eV, which increased to 1.51 eV upon annealing.
(Received December 6 2008)
(Accepted July 15 2009)
(Online publication September 22 2009)