水热处理对ZnO薄膜微结构及光学性能的影响

Effects of Hydrothermal Treatment on Microstructure and Optical Properties of ZnO Thin Films

基于溶液工艺和水热处理制备了ZnO薄膜。采用椭圆偏振光谱分析仪,原子力显微镜,X射线衍射仪研究和分析了水热处理温度对薄膜的微观形貌,光学特性,晶体结构的影响。实验结果表明,水热处理温度由110℃升高到130℃,薄膜光学带隙由3.19eV增大到3.31eV,而薄膜表面粗糙度从19.3nm降到12.9nm。然而,当处理温度超过140℃后,与130℃下处理的膜相比质量显著劣化。此外,130℃下水热处理的膜与500℃下高温退火的膜对比表明水热法有相似的光学特性,同时,XRD分析表明水热处理能改善晶体特性。证明了利用水热处理能够极大地降低溶液法制备ZnO薄膜所需的退火温度。

Zinc oxide thin films were prepared by solution method and hydrothermal treatment process. The effects of hydrothermal treatment temperature on microstructure, optical properties and crystal structure were studied by spectroscopic ellipsometry （SE）, atomic force microscope （AFM） and x-ray diffraction （XRD）. Results show that the optical band gap of the film increases from 3.19eV to 3.31eV, and the surface roughness decreases from 19.3nm to12.9nm when the hydrothermal treatment temperature increases from 110℃ to 130℃. However, when the treatment temperature exceeds 140℃, the quality of film is remarkably deteriorated, comparing to the quality of 130℃. In addition, hydrothermal method of 130℃ gets the similar optical properties as thermal annealing of 500℃, and XRD evidences that hydrothermal method improves crystal properties. All work indicates that hydrothermal method decreases the temperature of treatment when depositing zinc oxide thin films by solution method.