We investigated the effect of ZnO buffer layer on the formation of ZnO thin film by ultrasonic assisted spray pyrolysis deposition. ZnO buffer layer was formed by wet solution method, which was repeated several times. Structural and optical properties of the ZnO thin films deposited on the ZnO buffer layers with various cycles and at various temperatures were investigated by field-emission scanning electron microscopy, X-ray diffraction, and photoluminescence spectrum analysis. The structural investigations showed that three-dimensional island shaped ZnO was formed on the bare Si substrate without buffer layers, while two-dimensional ZnO thin film was deposited on the ZnO buffer layers. In addition, structural and optical investigations showed that the crystalline quality of ZnO thin film was improved by introducing the buffer layers. This improvement was attributed to the modulation of the surface energy of the Si surface by the ZnO buffer layer, which finally resulted in a modification of the growth mode from three to two-dimensional.

• 한인섭(서울과학기술대학교 신소재공학과) | In Sub Han (Department of Materials Science and Engineering, Seoul National University of Science and Technology, Seoul 01811, Republic of Korea)
• 박일규(서울과학기술대학교 신소재공학과) | Il-Kyu Park (Department of Materials Science and Engineering, Seoul National University of Science and Technology, Seoul 01811, Republic of Korea) Corresponding author