多孔硅薄膜纵向分辨Raman谱研究

Study on the Vertical Raman Spectrum of the Porous Silicon Film

采用高灵敏度的micro Raman系统研究了多孔硅(PS)在纵向的Raman效应,并研究了多孔硅尺寸对Raman谱的影响.实验中采用脉冲电化学腐蚀和直流电化学腐蚀两种方法制备PS样品,纵向Raman光谱的结果表明,在纵向不同深度,用脉冲电化学腐蚀方法制备的PS,Raman光谱不存在频移,而用直流电化学腐蚀方法制备的PS在多孔层深度为70～90μm处的Raman光谱有向低波数方向约40cm-1的移动,它是由于常规电化学腐蚀方法制备的PS不同深度的尺寸分布对量子效率的影响引起的.

Vertical Raman effects of the PS are studied by using the highly sensitive microRaman system. The effects of the PS size on the Raman spectra are also studied. PS samples in the experiments are prepared by means of both the DC electroetching and pulse electroetching. Results of the vertical microstructure show that at various depths between 70～90 μm beneath the DCetched PS surface there exists a 4 cm-1 shift towards the lower frequency side of the Raman spectrum. This is caused by the effect of the DCetched PS size at various depths on the quantum effect.