Exploring the Amorphous-to-Crystalline Phase Transition in Se 80 In 5 Te 15-x Bi x Chalcogenide Thin Films

This work pronounces the interchange from amorphous to crystallization phase in quaternary Se 80 In 5 Te 15-x Bi x chalcogenide thin films which was prepared by controllable melt quenching technique using a vacuum of 10 –5 Torr. Non-isothermal behaviour by DSC measurements was carried out to establish the amorphous as well as glassy state of the synthesized Se 80 In 5 Te 15-x Bi x alloys. For phase transformation, Se 80 In 5 Te 15-x Bi x chalcogenide thin films were performed by thermal annealing at different temperatures 343 K, 353 K and 363 K for 2 h followed by taking XRD (X- Ray diffraction) and FESEM measurements. After thermal annealing, Se 80 In 5 Te 15-x Bi x thin films were considerably transformed from amorphous to crystalline nature. The luminescence peak position with elevated intensity was slightly shifted when the annealing temperatures were increased. The annealed Se 80 In 5 Te 15-x Bi x thin films exhibited the increased absorption coefficients (α) and extinction coefficient (k) with decreased optical band gap when annealing temperatures were increased. The lowering in the optical band gap with temperature of annealing was described on the basis of transferred phase from amorphous to crystalline.