摘要
用直流辉光溅射法结合真空镀膜法制备出了一种“多层三明治结构”的光致发光材料—C(膜 ) /Si(SiO2 ) (纳米微粒 ) /C(膜 )夹层膜 ,然后分别在 40 0、6 5 0和 75 0℃退火 1h .在波长为 2 5 0nm的紫外光激发下 ,刚制备出来未经退火处理的样品具有一个在 398nm (3.12eV)处的紫光宽带PL1峰 .在 6 5 0℃退火后 ,又出现了一个在 36 0nm (3.44eV)附近的PL2 峰 .PL1和PL2 峰形状和峰位与退火温度和激发波长无关 ,但强度却与退火温度和激发波长密切相关 .结合形态结构分析可知 ,紫光PL1峰可用量子限制 -发光中心 (QC LCs)模型进行解释 :即光激发发生在SiO2 微粒内部 ,而光发射源于SiO2 与Si界面上的缺陷中心 .紫外荧光PL2 峰则源自SiC内部的电子
A new silicon-based luminescence material-C( Film) /Si( SiO2) ( nanometer particles)/C( Film) ( abbr. C(F)/Si(SiO2)(N)/C(F)) is made by sputtering silicon nano-particles on the amorphous carbon film in Ar gas firstly, then depositing amorphous carbon film on silicon nano-particles layer in vacuum. Finally, it has been annealed at 400,650 and 750degreesC for 1h respectively. The photoluminescence (PL) of the sample is tested by fluorescence spectrophotometer. Excited by 250 nm UV-Iight, the unannealed sample gives a strong PL1 band around 398 nm (3.12 eV). After annealed at 650degreesC, the sample gives not only PL1 band, but also gives another strong PL2 band around 360 nm (3.44 eV). The shape and peak position of PL1 and PL2 are independent on annealing temperature and excited wavelength. On the contrary, the intensities of PL1 and PL2 are strongly dependent on it: their intensities are the lowest after the sample annealed at 400degreesC and the highest after annealed at 650degreesC. The shorter the excited wavelength is; the stronger their intensities are. The intensity of PL1 band is directly proportional to the ratio of SiO2/Si. Related to the configuration analysis([10]), these results suggest that the excitation of photons of PL1 band occurs inside SiO2 nanometer particles, and the emission of photons comes from the defects at the interface between SiO2 and Si. PL2 band is due to electron-hole recombination inside SiC nanometer particles.
基金
国家教育部骨干教师资助项目~~
