DETERMINING OPTICAL CONSTANTS OF SELENIUM THIN FILMS USING THE ENVELOPE METHOD

Two Selenium thin films were deposited on glass substrates using thermal evaporation technique. The optical constants (refractive index, absorption coefficient and extinction coefficient and energy gap) were calculated using the Transmittance (T) spectrums of the films in the spectral range of 500-900 nm. The envelope method was used to determine optical constants. The calculated refractive index was found to be in the range of 2.60 to 2.85 and the Energy gap (Eg) was found to be 1.8 eV which are in agreement with other studies made using other procedures. The films were found to be amorphous according to the results obtained by XRD technique. This method can be used to have a good results for many tranparent thin films with more mathematical tools