溶胶凝胶法制备钙改性钛酸铅铁电薄膜及其光学性质研究

Preparation and Optical Properties of Ca-modified Lead Titanate Thin Films

用溶胶-凝胶法在(100)Si及石英衬底上成功地制备了钙改性钛酸铅铁电薄膜.X射线衍射研究结果表明,晶化好的PCT薄膜是多晶钙钛矿结构.用SEM、AFM对薄膜的形貌进行了表征,发现薄膜致密均匀、晶粒随着退火温度的升高而长大,700℃退火后薄膜的晶粒大约为55nm.用紫外-可见分光光度计在波长190～1000nm范围内,测量了不同温度退火的PCT薄膜的光学透射率.结果表明600℃、700℃、800℃退火的薄膜样品,其禁带能分别为3.74eV,3.71eV和3.66eV.

PCT thin films were prepared on (100)Si and fused quartz substrates by sol-gel process. The crystal structure was investigated using XRD and the results show that PCT thin films have a perovskite phase structure. SEM and AFM were respectively used to observe the surface morphology of the thin films. The films were homogeneous and crack-free. In the PCT30 thin films on (100)Si substrate, the average grain size was 55 nm when annealed at 700℃.The optical transmission spectra of PCT thin films were measured in the wavelength range 190-1000 nm. The films have good optical transparent properties. The band gap energy of the films decreases with the rise of annealing temperature.