J.Y. Lee

Effects of precursor concentration on ZnO nanorods grown on flexible PET substrate by hydrothermal synthesis

In this study, the effects of precursor concentration on the zinc oxide (ZnO) nanorods grown on flexible polyethylen terephthalate (PET) substrate with and without buffer layer were discussed. The concentration was varied from 0.05 to 0.5M. When we inserted buffer layer before hydrothermally growth of ZnO, better aligned ZnO nanorods were grown. At relatively middle concentration (from 0.2 to 0.3M), well-aligned ZnO nanorods were grown on PET substrate with and without buffer layer. The crystal structural properties and surface morphologies were examined by x-ray diffraction (XRD), and field emission scanning electron microscope (FE-SEM), respectively.

Effects of O 2 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 0W to 100W 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.

Characterization of ZnO Thin Films and Ga doped ZnO Thin Films Post Annealing for Transparent Conducting Oxide Application

Polycrystalline ZnO and Ga doped ZnO (GZO) films are deposited on glass substrate by RF magnetron sputtering at room temperature. The characteristics of ZnO and GZO films are investigated with X-ray diffraction measurement, UV-VIS-NIR spectrophotometer and hall measurement. The post-growth thermal treatment of these films is carried out in N2 ambient at for 30 min and an hour. ZnO and GZO films have different changing behavior of structural and optical properties by annealing. To use transparent conductive films for solar cell, films should have not only high transmittance but also good electrical property. Although as deposited GZO films have electrical properties than ZnO films, GZO films have not good transmittance properties. Consequently, we succeed that the high transmittance of GZO films is improved by annealing process.