Au/SiO_2纳米复合膜的形貌及发光特性

采用磁控溅射和退火法在Si(111)衬底上制备Au/SiO2纳米复合薄膜,并在两种实验模式下进行退火处理。模式A:不同的退火温度,退火20min;模式B:退火温度1 000℃,不同的退火时间。用扫描电子显微镜(SEM)、X射线衍射方法(XRD)和光致发光(PL)等测试手段对退火后的Au/SiO2纳米复合薄膜的表面形貌、微观结构和发光特性进行了分析。SEM结果表明,在模式A情况下,随着温度的增加,Au纳米颗粒的大小先增加后减小,这与XRD测试结果相吻合。PL结果表明,在模式B情况下,随着退火时间的增加,发光峰强度先增加后减小。在325nm波长下激发,440nm的发光峰与Au颗粒的大小和数量有关,而523nm的发光峰与纳米复合膜的结构有关,这与SEM平面图相吻合。实验结果表明,Au/SiO2纳米复合薄膜的表面形貌、微观结构和发光特性与退火温度及退火时间有很强的依赖关系。

Morphology and Photoluminescence Properties of Au/SiO_2 Nanocomposite Films

The Au/SiO2 nanocomposite films were fabricated on Si(111) substrates by radio frequency(RF) magnetron sputtering technique and annealing at different temperatures for 20 min(mode A) and at 1 000 ℃ for different annealing time(mode B).The surface morphology,microstructure and photoluminescence properties of the annealed nanocomposite films were analyzed by scanning electron microscopy(SEM),X-ray diffraction(XRD) and photoluminescence(PL).The SEM results demonstrate that the size of Au crystallites in mode A first increases and then decreases with increasing annealing temperature,corresponding to the results of the XRD spectra.The analysis of PL spectra in mode B shows that the intensity of the emission peak early increases and later decreases with increasing annealing time.The emission peaks of 440 nm and 523 nm obtained at the excitation wavelength of 325 nm are related to the size and quantity of Au particles and the structures of nanocomposite films,respectively,according with the SEM images.Experimental results indicate that surface morphologies,microstructures and photoluminescence properties of Au/SiO2 nanocomposite films show close affinity with the annealing temperature and annealing time.