采用直流反应磁控溅射法在K9玻璃和KBr衬底上制备了VO2薄膜,利用扫描电镜(SEM)、X射线衍射(XRD)、傅里叶红外光谱(FT-IR)对薄膜的形貌、晶相和分子结构等进行分析。结果表明,在氧气气氛下退火后,薄膜颗粒变得清晰可见,平均尺寸约25 nm,薄膜由非晶态结构转变为晶态的VO2,且在(011)方向出现明显择优取向生长。利用四探针对薄膜电阻温度特性的测试结果显示,薄膜经过O2气氛退火10 min后具有显著的电阻突变特征,24℃时的激活能为0.24 eV。实验结果表明,退火改变了薄膜的结构形貌,进而对薄膜的电学性能产生影响,选择合适的退火条件可以获得性能优良的VO2薄膜。
VO 2 films were prepared on glass and KBr substrates by DC reactive magnetron sputtering.The morphology,crystallization and molecular structure of the films were studied by scanning electron microscope(SEM),X-ray diffraction(XRD) and Fourier transform infrared spectroscopy(FT-IR),respectively.Results reveal that the particles of films prepared by annealing in oxygen become clearly visible,and the average particle size is about 25 nm.After annealing,the structure of films is changed from amorphous one to crystalline,and shows a VO 2 (011) preferred growth orientation.Square resistance characteristics of the films were measured by four-point probe method.The tests show that after 10 min annealing in oxygen,the films have a significant resistance mutation.The activation energy of vanadium oxide films is 0.24 eV at 24 ℃.Experimental results show that the annealing leads to the change of the morphology and structure of the films,and thus affects the electrical properties.Good performance of VO 2 thin films can be acquired by selecting appropriate annealing conditions.