多孔硅的微结构与发光特性研究

利用原子力显微镜（AFM）和光致荧光（PL）光谱对一系列直流腐蚀和脉冲腐蚀的多孔硅的微结构及发光特性进行了对比研究．表面和侧面的AFM结果表明，多孔硅表面呈“小山”状，有许多小的、突出的硅颗粒．在相同的腐蚀条件（等效）下，脉冲腐蚀的样品表面Si颗粒更加尖锐、突出，侧面的线状结构更明显，多孔硅层更厚．对应的PL谱，脉冲腐蚀的样品发光更强．量子限制效应的理论可以比较成功地解释这个结果 关键词：

STUDIES ON MICROSTRUCTURE AND PHOTOLUMINESCENCE PROPERTY OF POROUS SILICON

AFM and PL are adopted to study the morphological and photoluminescent characteristics of a series of porous silicon (PS) samples etched with direct current and pulsed current.The results of AFM indicate that there are many “hillocks” at the surface of PS samples and the microstructure of PS samples is quite different with different etching modes.The amount of the small Si particles formed by pulsed etching is more than that by direct current etching under the-equivalent etching-conditions and the particles appear more protruding and sharper by the pulsed etching.Moreover,PL spectra shows that it is easier to get photoluminescent PS samples with higher intensity by using pulsed etching method.The microstructure of PS samples plays a very important role in the generation of photoluminescence of porous silicon.