机构地区: 浙江大学材料科学与工程学系硅材料国家重点实验室
出 处: 《材料科学与工程学报》 2005年第2期163-166,共4页
摘 要: 以醋酸镍为原料 ,用溶胶 -凝胶法在石英衬底上制备了氧化镍薄膜 ,并利用X射线衍射、紫外 -可见吸收谱对样品进行了表征。结果表明 ,当热处理温度低于 80 0℃时 ,随着温度升高 ,石英衬底上生长的氧化镍薄膜的晶粒逐渐长大 ,其 (2 0 0 )面对应的衍射峰的强度增加 ,取向度提高。当热处理温度超过 80 0℃后 ,晶粒尺寸不但不再增加 ,反而略有下降 ,同时 ,取向度也略有下降。因此就晶粒大小及取向度而言 ,最佳热处理温度为 80 0℃ ,此时薄膜的晶粒尺寸最大 ,(2 0 0 )取向度最高。紫外 -可见吸收谱分析表明 ,氧化镍薄膜的禁带宽度也随着处理温度的变化而变化 ,其变化趋势与晶粒尺寸的变化正好相反 ,即禁带宽度在热处理温度为 80 0℃时有极小值。纳米尺寸粒子中存在的量子约束效应可以说明这一变化趋势。 NiO thin films were deposited on quartz substrates by sol-gel dip-coating method using Ni(Ac) 2·4H 2O as the starting materials. XRD measurement results showed that for process temperature below 800℃, the grain size, the (200) diffraction peak intensity, and the orientation factor of the (200) diffraction peak increased as the temperature increased. For process temperature above 800℃, the opposite phenomena were observed. So the optimum process temperature for the deposition of NiO film by this method was 800℃. Optical band-gap measured by UV-Vis absorption revealed that the band-gap of NiO thin films showed an opposite trend compared to the grain size, which can be qualitatively explained by the quantum confinement effect caused by small grain size in the film.