Si nanocrystals embedded in SiO2: Optical studies in the vacuum ultraviolet range

Article

关键词: SILICON NANOCRYSTALS;    CARRIER MULTIPLICATION;    LUMINESCENCE;    PHOTOLUMINESCENCE;    CONFINEMENT;    CENTERS;   

DOI  :  10.1103/PhysRevB.83.045308

来源: SCIE

【 摘 要 】

Photoluminescence excitation and transmission spectra of Si nanocrystals of different diameters embedded in a SiO2 matrix have been investigated in the broad visible-vacuum ultraviolet spectral range using synchrotron radiation. The dependence of the photoluminescence excitation spectra on the nanocrystals size was experimentally established. It is shown that the photoluminescence excitation and absorption spectra are significantly blueshifted with decreasing Si nanocrystal size. A detailed comparison of photoluminescence excitation and absorption spectra with data from theoretical modeling has been done. It is demonstrated that the experimentally determined blueshift of the photoluminescence excitation and absorption spectra is larger than the theoretical predictions. The influence of point defects in the SiO2 matrix on the optical and luminescence properties of the embedded Si nanocrystals is discussed. Moreover, it is demonstrated that no energy transfer takes place between the SiO2 and Si nanocrystals when the excitation energy is higher than the band-to-band transition energy in SiO2.

【 授权许可】

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