Spherical Growth and Surface-Quasifree Vibrations of Si Nanocrystallites in Er-Doped Si Nanostructures
2001; American Physical Society; Volume: 86; Issue: 14 Linguagem: Inglês
10.1103/physrevlett.86.3000
ISSN1092-0145
AutoresXinglong Wu, Yongfeng Mei, G. G. Siu, Ka-fu Wong, Keith M. Moulding, M. J. Stokes, C. L. Fu, Xiaoguang Bao,
Tópico(s)Semiconductor materials and interfaces
ResumoSi-based Er-doped Si nanostructures were fabricated for exploring efficient light emission from Er ions and Si nanocrystallites. High-resolution transmission electron microscopy observations reveal that Si nanocrystallites are spherically embedded in the SiO2 matrix. Energy-dispersive x-ray analysis indicates that the Er centers are distributed at the surfaces of nanocrystallites surrounded by the SiO2 matrix. Low-frequency Raman scattering investigation shows that Lamb's theory can be adopted to exactly calculate the surface vibration frequencies from acoustic phonons confined in spherical Si nanocrystallites and the matrix effects are negligible.
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