Dependence of Structure and Optical Characterization of (Bi2Te3) Films Prepared by Flash Evaporation on Annealing Temperatures


In this study Bi2Te3 stoichiometry alloy was fabricated by using melting method in the electric furnce at temperature (580 0C for 6h). Thin films (Bi2Te3 ) were deposited by flash technique under vacuum 10-5 Torr . The thickness measured of films was 500nm .the influence of annealing temperature (100 -200) 0C was studied structure and optical properties of Bi2Te3 thin films. Structural properties for thin films of Bi2Te3 were investigated by XRD and AFM analysis. The XRD analysis of alloy show that poly crystalline phase for Bi2Te3 stoichiometry while the films prepared were amorphous at room temperature and phase transition to polycrystalline under annealing with preffered orientation at (015) corresponding to( 2θ =27.639) .FT-IR measured were studied for Bi2Te3 in range of (400-4000 )cm-1 under annealing temperature and this measured show that decreasing of Eg with increasing annealing temperature ,this can be interpreted in term improved the crystal structure.