论文部分内容阅读
应用射频磁控共溅射方法和真空退火方法制备了GaAs SiO2 纳米颗粒镶嵌薄膜 .X射线衍射实验结果表明 ,经高温退火的薄膜中形成了面心立方闪锌矿结构的GaAs纳米晶粒 ,晶粒平均直径为 1.5— 3.2nm .吸收光谱展示了由于强量子限域引起的 1.5— 2eV的吸收边蓝移 .室温光致荧光 (PL)光谱显示了电子 重空穴激子与电子 劈裂空穴激子的近紫外和紫外双PL谱峰以及深俘获态的PL谱峰 .对实验吸收边蓝移量与有效质量模型的蓝移量的悬殊差别、俘获态PL谱的形成以及PL谱线的特征作了解释 .应用激光Z扫描技术测量了退火温度为 5 0 0℃的复合膜在非共振条件下的光学非线性 ,结果表明 ,复合膜的非线性折射率系数和非线性吸收系数都比块材GaAs相应的系数增大了 5个数量级 .光学非线性系数增大主要起因于强量子限域效应
GaAs SiO2 nanoparticle inlay films were prepared by radio-frequency magnetron co-sputtering method and vacuum annealing method.The results of X-ray diffraction showed that the GaAs nanocrystals with face-centered cubic sphalerite structure were formed in the films annealed at high temperature The average diameter of the particles was 1.5-3.2 nm.The absorption spectra showed a blue shift of absorption of 1.5-2 eV due to strong quantum confinement.The room temperature photoluminescence (PL) spectra showed that the electron heavy hole exciton and the electron splitting hole Excitons near the UV and UV dual PL peaks and deep trapping of the PL peak.For the experimental absorption edge of the blue shift and effective mass model of the blue shift of the disparity, the formation of trapped PL spectra and PL spectrum The optical nonlinearity of the composite film with the annealing temperature of 500 ℃ was measured by laser Z-scan technique. The results show that the nonlinear refractive index and the nonlinear absorption coefficient of the composite film are better than those of the non-linear absorption coefficient The corresponding coefficient of bulk GaAs increases by 5 orders of magnitude.The increase of optical nonlinearity coefficient mainly comes from the strong quantum confinement effect