The Effect of Tellurium Content(x) on the Optical and Electrical Properties of (Se 1-x Tex) Thin Films

Abstract

Thin films of Se 1-x Te x were fabricated by co evaporating the separate elements under vacuum on glass substrate. Careful was used in order to obtain a wide range of composition i.e. ( Se, Se 0.9Te 0.1, Se 0.8Te 0.2, Se 0.7 Te 0.3,Se 0.6Te 0.4,Se 0.5Te 0.5,…..,Te).The transmittance and the absorbance were carried out in the spectral range (400-2500nm)and the values of optical energy gap (Eg),the optical constants (refractive index(n),the extinction coefficient(k),the real (ε1)and imaginary (ε 2) part of dielectric constant were calculated. The effect of increasing tellurium content (x) in selenium films on the optical parameters was discussed. The results for electrical properties like d.c conductivity ( σDC ),concentration of charge carriers (nH ) and the activation energy (Ea )were also found which support those of the optical results.