利用快速熱氧化摻雜鉺之多孔矽室溫發光研究

Abstract

我們利用多孔矽經過快速熱氧化製造出奈米矽晶體(Silicon nanocrystals, nc-Si)，經由穿透式電子顯微鏡(TEM)、拉曼散射光譜(Raman)、可見光激發光(Photoluminescence)確定奈米矽晶體存在，並研究奈米矽晶體平均尺寸與發光特性光譜之間關係。最後再摻雜鉺原子於含有奈米矽晶體的結構，成功地量測到鉺原子在1.54μm紅外光激發光，並探討鉺原子發光與奈米矽晶體關係。 此篇論文，我們將以不同的電流密度製造出不同孔隙度(porosity)之多孔矽，經過快速熱氧化後形成不同平均尺寸的奈米矽晶體。藉由拉曼散射光譜紅位移及可見光激發光藍位移，可以發現它們位移量隨奈米矽晶體尺寸變小而增大。當將奈米矽晶體之樣品中摻雜鉺原子，發現鉺原子在1.54μm螢光發光強度隨著奈米矽晶體尺寸變小而增強。如同其它文獻所證實，奈米矽晶體的存在的確可以加強激發鉺原子發光，且發光效益也和奈米矽晶體尺寸有密切關係。

We successfully employed rapid thermal oxidized porous silicon (PS) to create silicon nanocrystals (nc-Si). In order to observe the size and the characteristics, experiments on different samples were investigated via transmission electron microscope (TEM)、Raman scattering and photoluminescence. After that, we doped Er ions into silicon rich SiO2 (SRSO) structure and successfully observed the infrared photoluminescence at 1.54μm from Er ions. The relations between infrared photoluminescence and average size of nc-Si were discussed in this study. In this work, we controlled different current density to vary the silicon porosity. The different average size of nc-Si were formed by changing the silicon porosity and rapid thermal oxidization. We observe the red-shift of Raman scattering and the blue-shift of visible photoluminescence from the average size of nc-Si. The intensity of infrared photoluminescence at 1.54μm from Er ions would increase as the decreasing of the average size of nc-Si. This fact means that the Er ions are excited by energy transfer process from the excited nc-Si and the conversion efficiency has relations with the average size of nc-Si.