Effects of O2 plasma power on the structural and surface morphologies of ZnO thin films grown on the flexible PES substrate by atomic layer deposition

ZnO thin films were deposited on polyethersurfone (PES) substrates by atomic layer deposition (ALD). We investigated the effects of O₂ plasma pretreatment from 0 W to 100 W before the ZnO growth. When the plasma power was increased, the PET substrate surface roughness was also increased. However, the surface roughness of ZnO on the roughest PET substrate with maximum plasma power pretreatment showed the smoothest value. The XRD (002) peak intensity of ZnO was increased with increasing plasma power. The morphologies of ZnO thin films were measured by atomic force microscope (AFM) and scanning electron microscope (SEM). And the crystal structural properties were analyzed by X-ray diffraction (XRD) method.