Structural, morphology and optical properties of AlxSb1-x thin films prepared by Pulsed laser deposition (PLD)

Abstract

AlxSb1-x compounds with different aluminum content (x=0.1, 0.3, 0.5, 0.7 and 0.9) were prepared by mixing the two elements in the appropriate ratios in quartz ampulla which then sealed and put in an oven at 1273 and left 5 hours. The obtained powder were grinded and then pressed in pellets shape which will be the target to prepare thin films samples. AlxSb1-x thin films were synthesized by PLD with ∼ 150nm in thickness. The structures of AlxSb1-x powders and thin films were determined using X–ray diffraction. The data revealed that all the prepare AlxSb1-x bulk and thin films have polycrystalline. The results showed that increasing of Al reduced the crystallinity of the prepared samples at the first but then the opposite take place. The AFM data indicated that the average grain size and average surface roughness showed non regular sequence with composition ratio. The optical constants transmittance has been measured from transmittance spectra. The extinction coefficient and imaginary dielectric constant show regular reduction with the increase of x value while return to increase at high aluminum content. The direct optical energy gap (Egopt) for allowed transition get to change in different manner to that of optical constants. The optical energy gap showed red shift by increasing of x content and then decreased for high x content value, the optical energy gap reach minimum value (1.3 eV) and maximum value (1.9 eV) at x= 0.9 and 0.7 respectively.