nc-SiC/SiO_2镶嵌薄膜材料的制备、结构和发光特性

采用二氧化硅/碳化硅复合靶,用射频磁控共溅射技术和后高温退火的方法在Si(111)衬底上制备了碳化硅纳米颗粒/二氧化硅基质(nc-SiC/SiO2)镶嵌结构薄膜材料。用X射线衍射(XRD),傅里叶红外吸收(FTIR),扫描电子显微镜(SEM)和光致发光(PL)实验分析了薄膜的微结构以及光致发光特性。实验结果表明,样品薄膜经高温退火后,部分无定形SiC发生晶化,形成β-SiC纳米颗粒而较均匀地镶嵌在SiO2基质中。以280nm波长光激发薄膜表面,有较强的365nm的紫外光发射以及458nm和490nm处的蓝光发射,其发光强度随退火温度的升高显著增强,发光归结为薄膜中与Si—O相关的缺陷形成的发光中心。

Preparation,microstructure and photoluminescence properties of embedded thin films of nc-SiC/SiO2

SiC nanocrystals embedded in SiO2 matrix on Si(111)substrates were prepared by RF magnetron co-sputtering with a SiO2/SiC composite target and subsequent high temperature annealing. The microstructure and luminescent properties of the films are determined by X-ray diffraction(XRD),Fourier transform infrared transmission spectroscopy(FTIR),scanning electron microscopy(SEM)and photoluminescence(PL)measurements. The results show that crystallization has taken place in the composite films after annealing and a part of amorphous SiC has been changed into β-SiC,which may nucleate into SiC nanocrystals embedded in SiO2 matrix. Strong ultraviolet band(365 nm)and blue bands(458 nm and 490 nm)PL from the films,which is excited by 280 nm light,are observed at room temperature. PL intensity increases with the increasing annealing temperature. PL is attributed to the Si-O related luminescent centers.