Analysis of Structural and Electrical Properties of Iron Sulfide (FeS2)Thin Films doped with Aluminum and Strontium impurities

Abstract

Abstract: Thin films of iron sulfide (FeS2) prepared by CBD technique were doped with aluminum (Al: 0.020.04M) and strontium (Sr: 0.02-0.04M) impurities at room temperature of 26 C. X-Ray diffraction (XRD) and four-point probe were used to analyze the structural and electrical properties of the thin films. The XRD results show that 0.02M of strontium impurities produced polycrystalline structure of the thin films with diffraction peak values located at Bragg’s angles, 2Θ of 14.71, 25.03 and 34.95, while the un-doped polycrystalline FeS2 thin films have diffraction peaks at 2Θ values of 19.81, 24.43, 31.45 and 36.73. Clearly, the contributing inphase reflections for the different diffraction angles occur from different orientations of lattice planes and/or different crystallite sizes caused by the Sr impurity. On the other hand, 0.02M of aluminum dopant produced mono-crystalline structure of the FeS2 thin film with 2Θ value of 24.97 o and a broadened full width at half maximum (FWHM). It is remarkable that the single peak of the mono-crystal due to Al impurity coincides with the highest intensity and sharper peak of the un-doped FeS2 thin film. The electrical resistivity of the thin films decreased while the conductivity increased with increase in impurity concentrations with non-uniform changes occurring from 0.02M for both impurities. The film thickness remained between 0.09-0.1μm but showed a more dramatic increase with impurity concentration from 0.02M for both impurities.