Optoelectronic properties of ZnO thin films grown by radio frequency magnetron sputtering

In the present work, Zinc oxide (ZnO) thin films with suitable optoelectronic properties required for application as transparent electrodes have been grown successfully on glass and silicon substrates by radio frequency magnetron sputtering technique at room temperature. A systematic study of the effect of film thickness on optical, electrical, and structural properties of the films was carried out by spectrophotometer, four-point probe, X-ray diffraction, and high-resolution transmission electron microscopy (HRTEM). It is observed that the film growth rate increases with increasing film thickness. The obtained ZnO films not only have an average transmittance greater than 90% in the visible region but also have low resistivity (rho = 4 x 10(- 2)ohm cm). All the deposited films are polycrystalline with a wurtzite structure and highly textured along the c-axis perpendicular to the substrate surface. As the film thickness increases, the intrinsic compressive stress decreases.