光学声子色散关系对多孔硅喇曼谱的影响

测量了多孔硅的喇曼光谱,观察到谱峰有明显的红移和非对称性展宽效应。用微晶模型对此现象进行了解释:认为谱峰的这种变化不完全是由尺寸的空间限制效应和多孔硅的应变造成的,更主要的是多孔硅的色散关系发生了变化。采用不同的色散关系对谱峰进行了拟合,发现色散关系对喇曼谱的拟合有较大的影响。

EFFECT OF DISPERSION RELATION OF OPTICAL PHONON ON RAMAN SPECTRA FROM POROUS SILICON

The Raman spectra of porous silicon films have been measured,The red shift and asymmetric broadening of the Raman signal have been described in terms of a model of phonon confinement. The results suggest that the change of Raman spectra peaks not only depends on phonon confinement and strain effects, but more depends on the dispersion relation of porous silicon as well. Using different dispersion relations,a series simulations have been made and it is found that the dispersion relation has obvious influence on Raman spectra simulations.