【摘要】 纳米GaAs颗粒通过射频磁控共溅法成功地被镶嵌在SiO₂薄膜中.通过不同基片温度下沉积的薄膜的Raman光谱观察到了明显的声子限域效应.其结果表明:当沉积时基片温度低于200℃时,X射线衍射和Raman散射均表现出非晶结构特征;当基片温度升高到300℃时,薄膜内的GaAs具有闪锌矿结构,同时其结构振动纵光学声子模对应的Raman散射峰将从非晶散射峰中分离出来,但同大块材料相比,该峰表现出明显的宽化和红移;随着沉积时的基片温度进一步提高,其宽化和红移相应地减小.更多还原

【Abstract】 GaAs microcrystallites embedded in SiO2 thin films prepared by r. f. co-sputtering technique was studied by Ramam scattering. Experimemt using films deposited at a series of substrate temperature (T8) were performed. As it is lower than 200℃, the GaAs particles embedded in SiO2 thin films are of amorphous feature which is characterized by XRD and Ramam scattering. After T8 reaches 300℃, the GaAs particles become crystallite with the average size of several nanometers, and with the same struture as that of bulk GaAs. The interface mode and downward shift of peak frequency of LO mode of GaAs particles were distinguished. For LO mode, the red shift and widening of peak occurred as compared to the value of bulk GaAs. With the increasing of T8, the amount of the red shift and widening decrease relatively due to the increase of the average size of GaAs particles.更多还原