Investigation into Texture, Preferential Orientation, and Optical Properties of Zinc Oxide Nanopolycrystalline Thin Films Deposited by the Sol-Gel Technique on Different Substrates

摘要

ZnO nanopolycrystalline thin films were deposited by the sol-gel technique on glass and silicon, and compared systematically via atomic force microscopy, scanning electron microscopy, x-ray diffraction, UV-Vis spectrophotometry, and fluorescence spectrophotometry. The thickness of the ZnO films was measured by ellipsometric microscopy. A higher preheating temperature was needed to obtain films with a strong preferential orientation. The optimal annealing temperatures for c-axis films on glass and silicon substrates were 525 deg C and 750 deg C, respectively. The relative intensity of the blue-green emission peak tends to increase with the annealing temperature. When the film is annealed in N_(2), the transmittance of the film reduces while the intensity of the blue-green emission increases.