We report the pressure dependence of Ge nanocrystals embedded in SiO2 film matrix on Si substrate using Raman scattering and finite element analysis. Delamination of SiO2 film from the Si substrate occurs at ～23 kbar...We report the pressure dependence of Ge nanocrystals embedded in SiO2 film matrix on Si substrate using Raman scattering and finite element analysis. Delamination of SiO2 film from the Si substrate occurs at ～23 kbar due to the large difference between the compressibility of the SiO2 matrix and Si substrate. The observed effect can be understood by the nonhomogeneous distribution of the elastic field in the Ge/SiO2/Si nanosystem. Previous high pressure PL results on the Si/SiO2/Si nanosystem can also be explained by the nonuniform distribution of the elastic field. Although our investigation focuses on the Ge/SiO2/Si nanosystem, our results could provide generally understanding on the elastic properties of different multi-component nanosystems.展开更多
The geometry,stability,binding energy and electronic properties of（SiO2）n and Ge（SiO2）n clusters（n = 7） have been investigated by Density functional theory（DFT）.The results show that the lowest energy structur...The geometry,stability,binding energy and electronic properties of（SiO2）n and Ge（SiO2）n clusters（n = 7） have been investigated by Density functional theory（DFT）.The results show that the lowest energy structures of Ge（SiO2）n are obtained by adding one Ge on the end site of the O atom or the Si near end site of the O atom in（SiO2）n.The chemical activation of Ge-（SiO2）n is improved compared with（SiO2）n.The calculated second-order difference of energies and fragmentation energies show that the Ge（SiO2）n clusters with n = 2 or 5 are stable.展开更多
文摘We report the pressure dependence of Ge nanocrystals embedded in SiO2 film matrix on Si substrate using Raman scattering and finite element analysis. Delamination of SiO2 film from the Si substrate occurs at ～23 kbar due to the large difference between the compressibility of the SiO2 matrix and Si substrate. The observed effect can be understood by the nonhomogeneous distribution of the elastic field in the Ge/SiO2/Si nanosystem. Previous high pressure PL results on the Si/SiO2/Si nanosystem can also be explained by the nonuniform distribution of the elastic field. Although our investigation focuses on the Ge/SiO2/Si nanosystem, our results could provide generally understanding on the elastic properties of different multi-component nanosystems.
基金Project supported by the foundation start up for high level talents of Shihezi university (No. RCZX200747)
文摘The geometry,stability,binding energy and electronic properties of（SiO2）n and Ge（SiO2）n clusters（n = 7） have been investigated by Density functional theory（DFT）.The results show that the lowest energy structures of Ge（SiO2）n are obtained by adding one Ge on the end site of the O atom or the Si near end site of the O atom in（SiO2）n.The chemical activation of Ge-（SiO2）n is improved compared with（SiO2）n.The calculated second-order difference of energies and fragmentation energies show that the Ge（SiO2）n clusters with n = 2 or 5 are stable.
