Effect of substrate temperature on the structural, optical, electrical, and morphological properties of zinc oxide thin films

The present paper reports on the effect of substrate temperature on the physical properties of zinc oxide (ZnO) thin films deposited using spray-pyrolysis technique. The films exhibit a polycrystalline nature with a preferred orientation along [002]. Furthermore, the average crystallites size increases with increasing the substrate temperature. The scanning electron microscopy results showed that the films were evenly distributed and homogeneous. The average optical transmittance varies in the range of 62 to 90% depending on the substrate temperature. On the other hand, with increasing the substrate temperature, the absorption coefficient decreases and the optical band gap varies in the range of 3.25 - 3.28 eV. The electrical conductivity of films varies between 18 and 58 mS.cm-1.