Where l, q and b are the wavelength of Cu ka1 radiation, Bragg
diffraction angle and full-width at half maximum (FWHM) of the
ZnO(002) diffraction peak, respectively.
According to the obtained results, with increase of seed layer
thickness, the FWHMof the (002) peak decreased and the grain size
increased.
The particle size of ZnO films analyzed using AFM is much
greater than by XRD. This may suggest that AFM data relates to the
particle size, while XRD relates to the grain size [22].