Department of Materials Science and Engineering, National Chiao Tung University, 1001 Ta-Hsueh Road, Hsinchu, Taiwan 30010, Republic of China.
Nanotechnology. 2010 Jul 23;21(29):295707. doi: 10.1088/0957-4484/21/29/295707. Epub 2010 Jul 5.
ZnO particles with an average size of about 5 nm were prepared via a sol-gel chemical route and the silane coupling agent, (3-glycidyloxypropyl)-trimethoxysilane (GPTS), was adopted to enhance the dispersion of the ZnO nanoparticles in ethyl glycol (EG) solution. A ZnO surface potential as high as 66 mV was observed and a sedimentation test showed that the ZnO precursor solution remains transparent for six months of storage, elucidating the success of surface modification on ZnO nanoparticles. The ZnO thin films were then prepared by spin coating the precursor solution on a Si wafer and annealing treatments at temperatures up to 500 degrees C were performed for subsequent preparation of ZnO thin film transistors (TFTs). Microstructure characterization revealed that the coalescence of ZnO nanoparticles occurs at temperatures as low as 200 degrees C to result in a highly uniform, nearly pore-free layer. However, annealing at higher temperatures was required to remove organic residues in the ZnO layer for satisfactory device performance. The 500 degrees C-annealed ZnO TFT sample exhibited the best electrical properties with on/off ratio = 10(5), threshold voltage = 17.1 V and mobility (micro) = 0.104 cm(2) V(-1) s(-1).
采用溶胶-凝胶化学路线制备了平均粒径约为 5nm 的 ZnO 颗粒，并采用硅烷偶联剂(3-缩水甘油丙基)三甲氧基硅烷(GPTS)来增强 ZnO 纳米颗粒在乙二醇(EG)溶液中的分散性。观察到 ZnO 表面电位高达 66mV，沉降试验表明 ZnO 前驱体溶液在储存 6 个月后仍保持透明，说明 ZnO 纳米颗粒的表面修饰成功。然后通过旋涂前驱体溶液在 Si 晶片上制备 ZnO 薄膜，并在高达 500°C 的温度下进行退火处理，以随后制备 ZnO 薄膜晶体管(TFT)。微观结构表征表明，ZnO 纳米颗粒在低至 200°C 的温度下发生融合，形成高度均匀、几乎无孔的层。然而，为了获得满意的器件性能，需要在较高温度下退火以去除 ZnO 层中的有机残留物。500°C 退火的 ZnO TFT 样品表现出最佳的电性能，导通/关断比=10(5)，阈值电压=17.1V，迁移率(微)=0.104cm(2)V(-1)s(-1)。
