Studying on the Preparation and Characteristics of Al2O3-Based Textured ZnO Thin Films

Using the magnetron sputtering technology, high quality Al₂O₃-based textured ZnO thin films (Al₂O₃/ZnO) which can be applied to solar cells´ light trapping effect were fabricated by controlling the preparation parameters properly. X-ray diffraction (XRD) and Scanning electron microscopy (SEM) results show that O₂ /(Ar+O₂) flow ratio has great influence on Al₂O₃/ZnO films surface morphology during Al₂O₃ layer growth, the Al₂O₃/ZnO films with pyramid structure morphology were easily prepared as O₂ /(Ar+O₂) flow ratio is in the range of 16.7%~50%. According to the measurement results of Al₂O₃/ZnO films´ resistivity and UV-Visible transmission spectra, the lowest resistivity of 0.0048Ωcm and optical transmission of larger than 80% were obtained for these Al₂O₃/ZnO films in this paper. After treated up to 720h under harsh environmental condition with relative humidity of 85°C and temperature of 80°C, these samples conductivity degradation is in the range of 12%~14% for Al₂O₃/ZnO films, which indicates that the Al₂O₃/ZnO films have better stability compared to ZnO films.