Annealing induced structural changes in sputtered AgInSbTe thin films and its implication on electrical properties

In this paper, we report on annealing temperature dependence of structural and electrical properties of the AgInSbTe films. X-ray diffraction shows an amorphous phase for the as-deposited films, while mixed crystalline phase for the films annealed above 160 degrees C (rhombohedral Sb/cubic AgSbTe2 and rhombohedral Sb/cubicAgInTe(2) phases for the films annealed between 200 degrees-350 degrees C and 350 degrees-400 degrees C respectively). The room temperature resistivity of the annealed films decreases from a value of 7.51 x 10(-4) to 5.32 x 10(-4) Omega cm with annealing temperature increasing from 200 degrees C to 300 degrees C, which is mainly due to large increase in mobility (3.4-7.3 cm(2) Vs(-1)) of charge carriers in p-type film. This mobility improvement can be easily related to increase in scattering time of charge carriers attributed to better crystallization and thereby reduced scattering. The annealing of the films above 300 degrees C resulted in partial evaporation of the material and increase in resistivity.