Effects Of Post Annealing On Structural, Electrical And Optical Properties Of Zno:Al Thin Films Prepared By Rf Magnetron Sputtering

Al doped ZnO (ZnO:Al, AZO) thin films were deposited on ordinary soda-lime glass (SLG) substrates by RF magnetron sputtering. Effects of post annealing (300 similar to 600 degrees C for 2 similar to 30 min in air and N-2, respectively) were studied. All the films were wurtzite structure with highly c-axis preferential orientation. Their electrical properties were relatively stable at the post annealing temperature of 300 degrees C. As the temperature further increasing, post annealing in air leaded to drastic degradation in the electrical properties, while that in N-2 had relatively small influence. Diffusion of alkali ions from SLG substrates was deduced to be one of the influence factors for electrical properties. The spectra measurements showed that the post annealing mainly affected the transmittance in the near-infrared and infrared (NIR-IR) range and the optical band gap (E-g). The variation of E-g was attributed to the Burstein-Moss (BM) shift modulated by many-body effects.