多孔硅的荧光及微结构

用扫描隧道显微和光致发光方法，观察了发光多孔硅的微结构形貌。发现多孔硅的光致发光主要源自其最表面层；该层是无定型的，但又不同于一般的非晶硅，而像是由大量纳米尺度的硅原子族组成的海绵状微结构；诸硅原子簇随机分布，相互间没有清晰的界面；没有观察到“线”状或“柱”状的结构；多孔硅的微结构有明显的分形特征，其发光很可能是源自此纳米硅材料中的量子尺寸效应。

Luminescence and structural study of porous silicon

canning tunneling microscopy was applied to observe the morphological feature of luminescent porous silicon. It was found that the luminescence of porous silicon might originate from its topmost surface layer which was regarded as an amorphous layer. However, unlike usual amorphous Si, it shows a sponge-like microstructure consisting of randomly distributed nanorsized silicon atomic cluster-like grains. There is no clear interface between clusters. No wire/column-like structure was observed. The microstructure of porous silicon surface shows obvious fractal.The luminescence from porous silicon is most likely due to quantum size effect in this nanorsized silicon material.